Uponor infra gravity systems eng

Gravity Systems Properties, designing, assembling Weholite, WehoDuo, WehoTripla, Weho Tanks, Weho Manholes

Contents

1. General ........................................................................................ 4 2. Properties of PE pipelines ........................................................... 7 3. Structure of gravity pipes ............................................................. 9 4. Hydraulic calculations for gravity flows ...................................... 10 5. Design parameters of PE and PP gravity pipes ........................ 15 6. Static calculations for PE and PP pipelines ............................... 16 7. Uponor program for pipeline calculations .................................. 24 8. Laying gravity pipelines in the ground ........................................ 26 9. Gravity pipe connections ........................................................... 39 10. Leak proof tests for gravity pipelines ......................................... 44 11. Installation of Weho tanks........................................................... 46 12. Installation of Weho manholes .................................................. 48 13. Installation of Weholite culverts.................................................. 51 14. Installation of Weholite marine system ...................................... 52 15. Renovation of gravity pipelines ................................................. 56 16. Transport and storage of PE and PP pipes ............................... 62 17. PE and PP chemical resistance – tables .................................. 64

Gravity Systems – Manual | 3

1. General 1.1. Applicable standards, guidelines and recommendations Uponor Infra Sp. z o.o. (formerly KWH Pipe Poland Sp. z o.o.) is Classification of Uponor Infra gravity systems and type approvals on the Polish certified to ISO 9001 and ISO 14001, in recognition of our efforts market to maintain the highest standards in manufacture and sale of our Product General application ITB GIG IBDIM products. Our quality control system is based on the standards applied in all UE countries. Each product has a relevant testing Gravity sewage systems, Weholite pipes and    underground systems, plan. Uponor Infra laboratory is fitted with state-of-the-art fittings renovation equipment, among the most advanced in the whole corporation.

PE pipes and fittings made by Uponor Infra are applied in building industry and have technical approvals issued by Research Institute of Roads and Bridges (IBDiM) and the Institute of Building Technology (ITB) in Warsaw.

WehoDuo pipes and Gravity sewage systems fittings



WehoDuo Drain pipes and fittings

Surface drainage, draining of waste dumps



WehoTripla pipes

Gravity sewage systems



VipLiner modules

Renovation



Weho manholes

Gravity sewage systems



Weho tanks and sewage treatment plants

Gravity sewage systems



  



Reference standards

Symbol

Title

PN-EN 13476-1

Plastics piping systems for non-pressure underground drainage and sewerage - Structured-wall piping systems of unplasticized poly(vinyl chloride) (PVC-U), polypropylene (PP) and polyethylene (PE) Part 1: General requirements and performance characteristics

PN-EN 13476-2

Plastics piping systems for non-pressure underground drainage and sewerage - Structured-wall piping systems of unplasticized poly(vinyl chloride) (PVC-U), polypropylene (PP) and polyethylene (PE) - Part 2: Specifications for pipes and fittings with smooth inside and outside surface, Type A

PN-EN 13476-3+A1

Plastics piping systems for non-pressure underground drainage and sewerage - Structured-wall piping systems of unplasticized poly(vinyl chloride) (PVC-U), polypropylene (PP) and polyethylene (PE) - Part 3:. Specifications for pipes and fittings with smooth inside and profiled outside surface, Type B

PN-EN 476

General requirements for components used in discharge pipes, drains and sewers for gravity systems

PN-ENV 1046

Plastics piping and ducting systems - Systems outside building structures for the conveyance of water or sewage - Practices for installation above and below ground

1.2. Material properties of PE and PP Property

Unit of measure

PE

PP

kg/m3

≥ 930

≥ 890

1

Density

2

MFR (PE 190˚C/5kg; PP 230˚C/2,16kg)

[g/10min]

≤ 1,6

≤ 1,5

3

Oxidation Induction Time (OIT) (200˚C)

[min]

≥ 20

≥8

4

E modules

[MPa]

≥ 800

1200÷2000

5

Tensile strength

[MPa]

18÷29

24÷31

6

Elongation to break point

[%]

≥ 350

-

7

Thermal linear expansion coefficiant

[10-4 K-1]

1,7

1,4

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1. General 1.3. Applications of gravity systems manufactured by Uponor Infra

Storm water drainage

Sanitary and combined sewer systems

Drainage of highways, car parks, airports and logistics centres

In-plant pipelines e.g. at sewage treatment plants

Technological and industry pipelines (coolant water, water and sewage management)

Mining drainage systems

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1. General c.d. 1.3. (continued) Applications of gravity systems manufactured by Uponor Infra

Derivative pipelines in water-power plants

Underwater pipelines

Renovations

Domestic septic tanks and sewage treatment plants

I

Water tanks: storage reservoirs and fire water tanks

II

Tanks for the agriculture – Weho Agro

Building for livestock

Manure channel

Weho Agro - liquid manure tank

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Transition tank

Manure plate

2. Properties of PE pipelines 2.1. Advantages of PE material Favourable properties of the PE material have had a decisive effect on general use of polyethylene pipes and fittings in water supply and sewage systems.

The most crucial advantages include:

• High abrasion resistance • Corrosion resistance (chemical compounds) • Very good fluid-flow properties • Non toxic material

• 100% tight joints • Flexibility • Light weight • Reliability

Asbestos pipes

Abrasion [mm]

Glass fibre pipes

Concrete pipes Clay pipes PVC pipes

PE pipes •

High abrasion resistance Abrasion resistance belongs to the most distinctive features of PE pipes among other materials used in pipeline construction. Owing to this advantage, PE pipes are used for transport of sludge, sand and other highly abrasive media.

Pipes made of commonly used materials were tested using the Darmstadt method. Pipe samples were filled with water and sand mixture and subjected to cyclic swinging motion.

Amount of the rubbed off pipe wall material was regularly measured. Test results demonstrate high abrasion resistance of polyethylene pipes. For example, a 0.3 mm loss of PE pipe surface was measured after 400,000 cycles while the loss measured for glass fibre pipes (GRP) was 6 - 8 times greater.

Number of cycles during test, N Source: University of Darmstadt (DIN 19534)

Corrosion resistance PE pipes are resistant to many chemical compounds – unlike pipes made of conventional materials that easily corrode and age when exposed to most of acids (excluding nitric acid), bases, salts, aliphatic solvents (pH 0 – 14). Polyethylene pipes are low-resistant to oxidants and aromatic solvents.

Resistance of PE pipes to chemical compounds depends on their temperature, concentration and working pressure.

Detailed information on chemical resistance of PE and other thermoplastics may be found in the ISO/TR 10358 Standard.

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2. Properties of PE pipelines Fluid-flow properties PE pipes retain low and constant roughness grade k = 0.01 mm. Lack of corrosion and resistance to clogging of PE pipes belong to the most important functional qualities of PE systems.

Non toxic Weho systems allow construction of drinking water tanks. Such tanks are made of PE material approved by the PZH (National Institute of Hygiene) in Warsaw.

100% tight joints PE gravity pipes can be welded together using polyethylene wire (extrusion method) or connected by means of socket joints, snap fasteners (SNAP-joint) or screw joints. Each type of connection is adapted to particular erection requirements, pipe size and the type of gravity system.

Flexibility With natural bend radius of outside diameters, PE pipes may be laid according to variations of the pipeline route and in many cases use of expensive fittings can be avoided. Flexibility is the distinctive feature of PE pipes among other conventional materials.

Low pipe weight Low pipe weight permits to reduce the costs and shorten the installation time.

Owing to their light weight, PE pipes do not require heavy equipment for laying a pipeline as well as for unloading the pipes at the construction site.

Approximate pipe weights PE DN 1000 - 120 kg/m Betras DN1000 - 700 kg/m Cast iron DN1000 - 300 kg/m Reliability Failure frequency of PE pipes is much lower than that of rigid pipes (concrete, clay, GRP). PE pipes are resistant to changing atmospheric conditions. The may be installed and transported both in low (below freezing point) and high ambient temperatures (tropical conditions). Therefore, PE pipes are used worldwide regardless of climatic conditions.

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3. Structure of gravity pipes 3.1. Ground load diagram

Earth pressure

Side support

Side support

Subgrade reaction PE gravity pipelines are interacting with ground as it constituted its integral element. By contrast with rigid pipes, flexible pipes do not crack under earth pressure and remain tight through the entire service life.

3.2. Construction of structural pipes

Weholite pipes (PE)

WehoDuo OD and WehoDuo Drain pipes (PE)

WehoTripla pipes (PP)

Diameters from 300 to 3000 mm

Diameters from 110 to 400 mm

Diameters from 110 to 400 mm

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4. Hydraulic calculations for gravity flows 4.1. A flow through the fully filled conduit Hydraulic analysis of gravity flow conduits is based on correct relations between variables of a flow and flow resistance resulting in velocity and potential energy losses. Hydraulic resistance is expressed as a loss of pressure head along the pipe length and as local losses resulting from disturbances of the stream. These relations are defined by the following DarcyWeisbach formula:

λ.ν2 κ i = ______ . 1+ _____ dw.2.g 100%

• (1)

i - unit pressure drop [-] lub [‰] g - acceleration of gravity [m/s2] λ - hydraulic resistance coefficient [-] dw - conduit inside diameter [m] v - mean velocity of flow [m/s] κ - proportional allowance for local losses as part of losses over conduit length [%]

For such flow conditions, hydraulic resistance coefficient representing resistance generated at the point of contact between liquid and the conduit wall, can be determined using the Colebrooke-White formula:

1 ____ = -2.log

λ

2.51 k _______ + _______ .

Re λ 3.71.dw

• (3)

k - absolute roughness of conduit wall surface [m] Re - Reynolds number calculated from the formula:

Re =

v.dw _____

ν

• (4) v - mean velocity of flow [m/s] ν - coefficient of kinematic viscosity [m2/s]

Mean velocity of flow may be calculated using the formula: v

• (2) Q - mean flow rate [m3/s] Turbulent flow occurs in transient range between hydraulically smooth and totally rough conduits (the so called B zone) in pipelines with free surface of liquid.

4.Q = ______ . 2 π dw

Coefficient of kinematic viscosity depends on type and temperature of a liquid. The table below shows coefficients of viscosity for temperature range between 2 and 25 degrees

Celsius. Uponor Infra computer program makes it possible to select liquid temperature in the range between 0 and 60 degrees Celsius

Table 4.1.a Values of the coefficient of kinematic viscosity ν [m2/sec] depending on temperature and concentration of the matter suspended in liquid wastes:

Temperature [°C]

Water

2 5 10 20 25

1,67 x 10-6 1,52 x 10-6 1,31 x 10-6 1,01 x 10-6 0,90 x 10-6

100 mg/l 2,17 x 10-6 1,60 x 10-6 1,33 x 10-6 1,02 x 10-6 0,90 x 10-6

Liquid wastes with concentration of suspended matter 300 mg/l 3,17 x 10-6 1,76 x 10-6 1,37 x 10-6 1,02 x 10-6 0,91 x 10-6

500 mg/l 4,17 x 10-6 1,92 x 10-6 1,41 x 10-6 1,04 x 10-6 0,92 x 10-6

In the existing design practice fixed value of the coefficient of kinematic viscosity both for water and liquid wastes is usually assumed: ν = 1,31 * 10-6 m2/s for water (liquid wastes) temperature of 10° C.

If the above formulas are combined in one and standard liquid temperature is assumed at 10 degrees Celsius, mean flow rate can be calculated using the following formula:

Conduit wall relative roughness depends on conduit material and pipe inside wall surface wear. As regards PE pipes, standard value for k is 0.01 mm. By assuming respective roughness the type of transported liquid may be modelled. For pipelines carrying liquids containing considerable amount of deposits bigger roughness should be assumed - according to their content and up to a value between 0.05 and 0.4 mm.

Q = - 6.598.log

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0.41 k __________ _______ + 106.dw. dw.i 3.71.dw

. dw. dw.i

• (5) This formula is a basis for preparing flow nomograms. It combines three quantities essential in hydraulic dimensioning – rate of flow, pipe bottom falling gradient (pressure drop) and pipe diameter.

4. Hydraulic calculations for gravity flows Basing on the flow nomograms it is possible to determine one of the three values mentioned above if two values are known. In Uponor Infra program designed for determination of the required value, iteration method is used. Additionally, consideration was given to the liquid temperature.

• (6)

τmin imin = ______ γ.Rh

Value of hydraulic radius used in the above formula should correspond to the type of liquid flowing through a pipe.

In case of industrial and municipal waste water systems - hydraulic radius corresponding to filling ratio of 60% is assumed while in case of rain-water disposal systems they are considered as fully filled with water.

Minimum tangential stresses are assumed 2.20 N/m2 and 1.47 N/m2 respectively.

Rh - Hydraulic radius [m] min - minimum tangential stress on the pipe-liquid border [N/m2]

τ

4.2. Minimum conduit bottom falling gradients In case of sewage systems, hydraulic gradient is limited by minimum liquid flow velocity necessary for transport of sludge. This velocity is called self-cleaning velocity.

Table 4.2.a. Minimum self-cleaning velocities

Pipe type

Sewage system, Vmin [m/s] Rain-water

Sewage

Combined sewage system

Weholite

0,6

0,8

1,0

WehoDuo

0,6

0,8

1,0

WehoTripla

0,6

0,8

1,0

4.3. Flow through partially filled conduits In design of gravity flow conduits their partial filling is often assumed. Consequently, the formulas applying to fully filled conduits are corrected accordingly by introducing a coefficient depending on the h/dw ratio (see the diagram next to this text).

1 0,9 0,8 0,7 0,6

h/dw

αQ - flow rate for partially filled conduit to flow rate for fully filled conduit ratio [-]

αv - flow velocity for partially filled conduit to flow velocity for fully filled conduit ratio [-] αA - fluid stream cross section for partially filled conduit to conduit cross section ratio [-]

0,5

αQ

αv

0,4 0,3

αA

0,2 0,1

0 0,1 0,2 0,3 0,4 0,5 0,6 0,7 0,8 0,9 1 1,1

Gravity Systems – Manual | 11

4. Hydraulic calculations for gravity flows 4.4. Comparison of pressure losses and flow capacities of the pipelines made of various materials These calculations were made to compare flow capacity losses in gravity pipelines made of various materials. Change in condition of pipeline inner wall surface after several years of operation was also taken into consideration.

For clarity of comparison the same inside diameter (D = 500 mm) was assumed. Coefficient of kinematic viscosity was assumed to be ν = 1,31 * 10-6 m2/sec at water (liquid waste) temperature of 10°C. Remaining values used in calculations are shown in the tables below.

Gravity pipeline flow capacity for transport of liquid wastes as well as flow velocity in fully filled conduit: D = 500 mm, hydraulic gradient l = 0.2%, filling ratio h = D (0.5 m).

Coefficient of pipeline losses was calculated using the

Colebrook-White formula.

Calculation results explicitly indicate that PE and PP conduits offer much less resistance to flow and much bigger flow capacity as compared with the conduits made of conventional materials – regardless of their operation time. These differences increase considerably in favour of PE and PP pipes as operation time becomes longer. In the first place, this results from little absolute roughness of the pipe that practically remains constant during operation.

Table 4.4.a. Flow capacity of PE and PP pipes in comparison with the pipes made of other materials

Material

PE, PP Steel PVC Reinforced concrete

New Old New Old New Old

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Absolute roughness

Flow rate

Flow capacity reduction as compared with PE and PP pipes

k [mm]

Q [l/s]

[%]

0,01

235

0

0,1 3,0 0,05 0,07 0,5 3,0

220 153 227 224 193 153

6,4 34,9 3,4 4,7 17,9 28,1

4. Hydraulic calculations for gravity flows 4.5. Nomograms for hydraulic calculations A nomogram for hydraulic calculation of fully filled Weholite pipes at temperature of 10ºC and roughness k = 0.01 mm using the Colebrook-White formula 10 100

20

40

60

80

100

200

400

Flow rate Q [dm3/s] 1000 600

800

2000

4000

6000

10000

8000

20000

40000

100000 100

60000 80000

80

80 60

v=

40

v= v=

3,0

50 0 60 0

8

v= v=

1 0,8

v=

0,6 0,4

v=

1,0

0,8

0,6

2

1

Unit pressure drop H [‰ ]

DN 2

DN DN 140 0 DN 150 16 0 00 DN 18 00 DN 20 00 DN 2 DN 200 2 DN 400 DN 260 0 DN 280 30 0 00

12 00

10 00

4

DN

80 0

90 0

1,5

6

DN

70 0

2,0

DN

v=

4

20

DN

Unit pressure drop H [‰]

6

40

4,0

DN

v=

DN

8

6,0

5,0

10

DN

DN

10

v= 40 0

DN

35 0

30 0

20

60

0,8 0,6 0,4

0,4 m/s

0,2

0,2

0,1 10

20

40

60

80

100

200

400

600

800

1000

2000

4000

6000

8000

10000

20000

40000

0,1 100000

60000 80000

Flow rate Q [dm 3/s]

Nomogram do obliczania hydraulicznego ca•kowicie wype nionych rur WEHOLITE SPIRO , dla temperatury 10oC i chropowato ci k=0.01 mm

A nomogram for hydraulic calculation of fully filled WehoDuo OD pipes at temperature of 10ºC and roughness k = 0.01 mm using the Colebrook-White formula

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4. Hydraulic calculations for gravity flows A nomogram for hydraulic calculation of fully filled WehoTripla pipes at temperature of 10ÂşC and roughness k = 0.01 mm using the Colebrook-White formula

1 4 | Gravity Systems – Manual

5. Design parameters of PE and PP gravity pipes 5.1. Ring stiffness Pipe section stiffness is characterized by the so called ring stiffness. Ring stiffness depends on geometry of a pipe (diameter and wall thickness) as well as on the strength of the structural material.

As regards pipes made of the most popular plastics: PE, PVC and PP, their ring stiffness marked with SN should be determined according to the Standard PN EN ISO 9969 “Thermoplastics pipes. Determination of ring stiffness”.

a) Ring stiffness – as per Standard ISO 9969 – is determined experimentally following the described procedures consisting in measurement of the force causing 3% pipe deflection within 3 minutes.

This force varies with time during the test and is acting on the pipe with constant speed.

b) Another method for determination of ring stiffness is based on the DIN 16961 Standard. Even though this method is not legally binding in Poland, certain German companies still use it. In this method constant pressure is applied to the pipe and pipe deflection is measured after 1, 6 and 24 hours. 24-hour deflection under defined load should be 3% (the so called Constant Load Method). Pipe stiffness according to the DIN method can be calculated from the following formula:

SN = ER×I / D3 [kN/m2] where: ER - modulus of elasticity of the structural material I - unit moment of inertia of the pipe wall D - mean (neutral) pipe diameter

In Poland, the PN EN ISO 9969 Standard has been legally binding for a few years. For customer’s information the manufacturer should always make reference to the standard he used to determine particular ring stiffness. Failure to do so may lead to wrong interpretation of strength properties of a pipe.

SR (ATV) = ER×I / rm3 [kN/m2] where: ER - modulus of elasticity of the structural material I - unit moment of inertia of the pipe wall rm - mean pipe radius

In case of solid wall pipes their ring stiffness may be determined using the above mentioned methods.

Table 5.1.a. Ring stiffness SN according to different methods

SN [kN/m2] acc. ISO9969

SN [kN/m2] acc. DIN16961

2

7.6

4

15.2

6

22.8

8

30.4

10

38.0

12,5

47.5

16

60.8

where: SN – ring stiffness of a pipe [kN/m2] Table 5.1.b. Ring stiffness (acc. to ISO9969) of structural pipes and ring stiffness values of solid wall (pressure) pipes.

Gravity pipelines Ring stiffness SN [kN/m2] Pipe Weholite WehoDuo WehoTripla

[-] [kN/m2] [kN/m2] [kN/m2]

SN* 2;4;6;8;10;12,5;16 8 8;10;12,5;16

*- other ring stiffnesses - on request

Pressure pipelines Ring stiffness SN [kN/m2] Pipe WehoPipe

SDR [-] [kN/m2]

33 2,5

27,6

26 5

22

21 10

17,6

17 19

13,6 38

11 75

9 150

SDR – Standard Dimension Ratio of solid wall pipes [SDR = Dn/e, Dn = nominal diameter, e= wall thickness]

Gravity Systems – Manual | 1 5

6. Static calculations for PE and PP pipelines 6.1. Interaction between pipe and ground – flexible and rigid pipes carrying capacity of flexible pipes depend on the way they are Behaviour of the pipe under load depends on its stiffness. assembled as well as the type of soil.

Flexible PE pipes interact with the ground and form stable As regards rigid pipes load is mainly taken by the pipe ground-pipe system. Plastic pipes belong to the category of material. When the load exceeds permissible value damage flexible pipes. Flexible pipe deflects under load and exerts of the pipe occurs. Standards on rigid pipes define pressure on the surrounding earth. This generates reaction load-carrying capacity as cracking strength as measured in of the ground that in fact resists further pipe deformation. standard test being maximum permissible pipe load.

Amount of pipe deflection may be limited through proper selection of ground material and workmanship. Therefore,

Flexible pipes

Pict 6.1.a. 17t caterpilar, 0,5m of cover. No deflection is visible. Pipe stiffness is 2kN/m2.

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Rigid pipes

6. Static calculations for PE and PP pipelines 6.2. Permissible pipe deflections Thermplastics (PE and PP) are viscoelastic materials.

Rheologic processes that is proceeding over long period of time take place in these materials. They include creeping and stress relaxation. Creeping is the increase of deformation under constant stress while relaxation consists in reduction of stress over time with constant deformation values.

Consequently, when deflection of a pipe under load does not

increase any longer, gradual reduction of stress in the pipe wall follows and this prevents pipe from damage.

Long lasting stability of the pipe in the ground is achieved and the ground itself becomes naturally stabilized. Density and consolidation of soil are accelerated as an effect of various factors, such as vibration, dynamic loads, soil own weight and changeable underground water level.

Fig. 6.2.a. Change of flexible pipe deflection over time

Table 6.2.a. Maximum permissible deflections of PE pipes on account of long-term operation

Stage of work

Deflection %

Initial phase Phase 1

Before installation Pipe assembly

3-5 % 3-5%

Phase 2 (2-3 years after installation)

Soil self-compacting

3-5%

If there is road traffic above the pipeline, maximum deflection will be achieved within much shorter period of time than in the case of static loads only.

In most cases, dynamic loads (generated by traffic) have no effect on final deflection.

6.3. Structural analysis Ring stiffness SN should be regarded as auxiliary parameter only in pipe selection process. Selection of pipes is based on dimensional analysis with consideration given to their foundation and load conditions followed by analysis of actual safety of the structure in question.

In case of laid in ground rigid pipelines made from conventional materials such as cast iron, concrete or clay basic dimensioning criterion is permissible stress or destructive force defined by the manufacturer. These boundary values are compared with actual values occurring in the case under study. Next, pipe safety in the assumed conditions of installation and loading are evaluated.

Flexible thermoplastics pipes are dimensioned in a different way. Here, basic dimensioning criterion is relative vertical deflection of a pipe as well as verification of cross-section buckling stability. Structural analysis of PE pipes may be carried out using the Scandinavian Method or according to the guidelines given in ATV A 127.

However, it is recommended to use the Scandinavian Method (Molin Method) and the algorithm given below is based on this very method.

Gravity Systems – Manual | 1 7

6. Static calculations for PE and PP pipelines The rules of structural design concerning rigid and flexible pipes have been drawn up by Spangler. General formula to determine relative deflection of both rigid and flexible pipes is as follows: (1)

C1.q δ_ = ___________

D

C2.SR+C3.Ss

q - vertical load C1, C2, C3 - coefficients SR - pipe ring stiffness SS - ground stiffness (depending on ground compression modulus E’s) There are many methods for calculating strength (among others are British, German, Austrian, French and Swedish

methods) based on classical Spangler formula. They differ in approach to the matter of strength of plastic pipes (individual coefficients), way of calculating pipe ring stiffness SR (basing on EN, ISO or DIN) as well as extent of complexity.

Certain methods, such as ATV 127 are based on theoretical assumption of ground and water conditions and give theoretical results.

Scandinavian Method (Molin Method) is based on a few dozen years of experience and on the analysis of interaction between pipeline and the ground in actual conditions of installation.

6.4. Adaptation to the legally binding standards Scandinavian Method for dimensioning of laid in ground pipelines has been adapted to the requirements of the Polish Standards. Modifications concern conditions for laying pipelines in excavations. Branch Standard BN-83/8836-02 “Conduits laid below the ground. Earth work. Requirements and acceptance tests” as well as National Standard PN92/B-10735 “Sewage system. Sewers. Requirements and acceptance tests” became a legal basis. These standards are used in partial and final technical acceptance of earth work

necessary to lay down water conduits, sewers, gas piping and heating pipelines in areas not affected by mining damages.

Therefore, use of the algorithm has to meet the requirements stipulated in these Standards.

Method for static calculations according to Molin has been worked out basing on the book: “Plastic Pipes for Water Supply and Sewage Disposal” by Lars-Eric Janson, Stockholm 1999, 3rd edition.

6.5. Static calculations for pipes using the Molin Method The Molin Method enables the designer easily and with sufficient accuracy to assume the values of parameters of pipeline installation valid in the conditions existing in Poland.

The results obtained are close to the actual values. This is confirmed by the measurements of thermoplastics pipe deflections carried on in Poland (see Alferink F. “Deflection Measurements in Poland; Wavin M&T, 1995) and in Europe (see TEPPFA – The European Plastics Pipe Association “Design of Buried Thermoplastics Pipes. Results of a European research project”, March 1999). The advantage of this method is that it is an empirical method rather than theoretical. It was worked out basing on the results of tests of pipelines installed and operated in various conditions. It is less sensitive to departures from design values during execution. Since the Scandinavian Method (Molin Method) concerns plastic pipelines only its form is more simple - in contrast to ATV method that requires more parameters but may be applied to both rigid and flexible pipes.

Basing on theoretical analysis and experience gained in flexible pipes, basing on the formula (1), Molin formulated an expression for maximum pipe deflection (δ/D)m – calculated from the value of theoretical pipe deflection (δ/D)q – after considering the values related to anticipated installation conditions (lf) and subsoil (sub-crust) quality (Bf):

1 8 | Gravity Systems – Manual

Fig. 6.5.a. Flexible pipe deflection over time

(2)

_δ = δ_ + I + B f Dm Dq q

6. Static calculations for PE and PP pipelines 6.6. Pipe deflection Theoretical deflection of a pipe under the load of soil and vehicular traffic is: (3)

Ring stiffness of SR pipe (according to ISO)

E . l1 SR = ____ D R3

q(C . b1-0,083 . K0) _δ = _________________ D q 8 . SR + 0,061 . ES

C - coefficient of load concentration C=1 b1 - coefficient of load distribution for pipe bearing angle

α =180o b1 = 0,083

K0 - coefficient of static earth pressure K0 = 0,5 E`s - ground compression modulus

I - moment of inertia of pipe cross section [m4/m] E - modulus of elasticity of pipe material [kN/m2] assumed for PE: momentary value E = 800 000 kPa sustained value El = 200 000 kPa DR - neutral axis diameter [m]

6.7. Vertical load Vertical load q caused by earth weight, hydrostatic thrust and vehicular traffic, is:

Table 6.7.a. Values of specific gravity of dry ground γgs

Specific gravity [kN/m3]

Type of ground

(4) q = qs+qw+qtr where:

Sand

17÷19

qs - earth weight qs = γgs(H-h) + γgm(h-D+s) [kN/m2] qw - hydrostatic thrust of underground water

Sandy clay

17÷19

Thick clay

18÷22

Sandy and dusty loams

17÷22

Loams

17÷22

qw = γw(h-(D/2)+s) [kN/m2] qtr - load caused by vehicular traffic [kN/m2]

γgs - specific gravity of dry ground; here γgs = 19 kN/m3 γgm - specific gravity of watered ground; here γgm = 11 kN/m3 γw - specific gravity of water; here γw = 10 kN/m3 D - pipe outside diameter [m] s - pipe wall thickness

Traffic load qtr according to Swedish Standard Effect of vehicular traffic on pipe loading is expressed as pressure distribution according to Boussinesq theory. In Sweden, type 2 of traffic is commonly assumed – according to the model shown in Fig. 6.7.a.

Diagram 6.7.a presents pipe vertical loads generated by the traffic depending on thickness of cover Hp. Load includes the dynamic load coefficient of 1.75. Dynamic load coefficient

decreases with increased thickness of the cover Hp. At a depth of 6 m this coefficient becomes 1. In the program, no effect of traffic generated load is assumed for depths Hp exceeding 5.5 m.

Fig. 6.7.a. Vertical loads qtr [kN/m2] caused by vehicular traffic depending on thickness of cover Hp [m] 100 80 60

qtr

Wheel load 130 kN Axle load 260 kN

40 20

0

Fig. 6.7.a. Swedish equivalent for calculation of axial load – Type 2.

1

2

3

4

5

6

Thickness of cover above the pipe top Hp [m]

Gravity Systems – Manual | 1 9

6. Static calculations for PE and PP pipelines Traffic generated load qtr according to German Standards (ATV A127, DIN 1072, DIN4033).

Guidelines of the German Standard ATV A127 single out three types of standard loads in evaluation of load carrying capacity of pipelines exposed to traffic loads. These are: - SLW60 – standard vehicle with gross vehicle weight of 600 kN and wheel load of 100 kN - SLW30 – standard vehicle with gross vehicle weight of 300 kN and wheel load of 50 kN - LKW12 – standard vehicle with gross vehicle weight of 120 kN and front wheel load of 20 kN and rear wheel load of 40 kN. Load acting on the top of pipe and caused by particular type of standard vehicle can be calculated using the following formulas:

(5) pv = ϕ . aF . F where: ϕ – dynamic coefficient acc. to DIN 4033 (6)

(7)

pF =

FA _____

ra .π 2

.1

1 _ ________ 2 rA 1+ ___ Hp

_3

2

+

.

3 FE ________ 2

2.π.H p

1 ________ rE 1+ ___ Hp

5_ 2

0.9 aF = 1- _______________ .H2p+ H6 p 4 ____________ 0.9 + 1.1. D 2/3 m

dm =

dw + dz ________ 2

Table 6.7.b. Coefficients used in calculations of traffic generated load qtr

FA

FE

rA

rE

[kN]

[kN]

[m]

[m]

SLW60

100

500

0.25

1.82

SLW30

50

250

0.18

LKW12

40

80

0.18

Type of load

Type of load

ϕ

SLW60

1,2

1.82

SLW30

1,4

2.26

LKW12

1,5

Application of relieving slab or stable road surface If it is necessary to lay a pipeline at a relatively shallow depth with heavy traffic load, an effective method to decrease the value of traffic load is application of a relieving plate. A slab made of reinforced concrete or concrete, which creates the road surface (or stable road surface) causes that the distribution of stress in the ground is more uniform and the load acting on the pipe decreases. The effectiveness of stress reduction in the ground depends on the dimensions of the slab. Thanks to the application of the slab, the concentrated load coming from the wheels of vehicles is uniformly distributed over a large area. This solution can be reasonably applied in the case of shallow pipelines covered by a 1-2 m layer of ground since the stress in the ground caused by the traffic load radically decreases with the increase of depth.

The programme assumes that the normal vertical stress

a b

σz =

3 ⋅ q ⋅ z3 1 ⋅ dxdy 2 ⋅ π ∫0 ∫0 R 5 ( x, y )

xis

ea

elin

pip

under the relieving slab is uniformly distributed and corresponds to the load of vehicle axis applied on the surface of the ground by means of a typical road slab (IOMB, MON) covering an area of 3.0 x 1.0 m.

In accordance with PN-81/B-03020 standard, the stress under the corner of a rectangular area of axb dimensions, loaded with continuous uniform load q, should be determined on the basis of the following formula:

Other types of loads were described in Underground pipes - static calculation in Uponor Infra calculation program.

calculaton point

Fig. 6.7.b. Diagram of vertical stress under the corner of the slab.

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6. Static calculations for PE and PP pipelines 6.8. Coefficients If i Bf Coefficients lf and Bf have been determined basing measurements of deflection of many plastic sewage pipes in Sweden and other countries.

Their value is influenced by the following factors:

- excavation shape

- traffic of heavy vehicles during construction work

- type of equipment and the method used for soil compacting

- irregularity of subgrade surface

- frequency and quality of supervision

- skills and experience of personnel Recommended values of coefficients were used on assumption that:

- The pipe was backfilled with sand, gravel or soil belonging to the group 1-4

- The pipeline must not be laid down directly on the ground covered with stones

Fig. 6.8.a. Combined trench

Table 6.8.a. Recommended values of coefficient If for particular installation conditions If

Recommended values of coefficient If for particular installation conditions Pipe in the combined trench - lack of supervision 1-2% (2% assumed) (Fig. 6.8.a.)

- with supervision 0% Intensive heavy vehicle 1-2 % traffic during construction (depending on Hp - value of 1 with Hp < 1.5 m (Fig. 6.8.b.) to 2% is assumed) Compaction of the first 30 cm layer above the pipe using heavy equipment > 0.6 kN (Fig. 6.8.c.)

0-1% (0% assumed – acc. to pipe-laying instructions first 30 cm layer above the pipe should not be compacted with the use of heavy equipment > 0.6 kN)

Table 6.8.b. Recommended values of coefficient Bf for subgrade quality

Recommended values of coefficient Bf for subgrade quality Very accurate execution

Standard execution

Without supervision

2%

4%

With supervision

1%

2%

Subgrade without stones

Fig. 6.8.b. Intensive heavy vehicle traffic during construction with Hp < 1.5 m

Fig. 6.8.c. Do not compact first 30 cm layer of backfill above pipe using heavy equipment (> 0.6 kN)

6.9. Compression modulus E’s of the pipe surrounding ground Soil compression modulus E’s depends not only on degree of compaction but also on type of soil and thickness of cover Hp. Diagram 6.9.a shows minimum values of ground compression modulus E’s for underground water level below pipe and specific gravity of the backfill of 19 kN/m3 and compaction degree acc. to modified Proctor for such grounds as loam, sand and gravel.

For covers Hp exceeding 6 m constant value of E’s, corresponding to Hp=6m were assumed.

4000

4000

3500

3500

3000

3000

100%

2500

E's [kPa]

E's [kPa]

Diagram 6.9.b. shows minimum values of E’s for underground water level above pipe and compaction degree acc. to modified Proctor for such grounds as loam, sand and gravel.

For covers Hp exceeding 6 m constant value of E’s, corresponding to Hp=6m were assumed.

90%

2000

85%

1500

80%

1000

0

1 2 3 4 5 Thickness of cover above the pipe top Hp {m}

90%

2000 1500

85%

1000

75%

500

100%

2500

80%

500 6

Diagram 6.9.a. Ground compression modulus E’s depending on the modified Proctor density of soil and Hp for underground water level below pipe

75% 0 1 2 3 4 5 Thickness of cover above the pipe top Hp {m}

6

Diagram 6.9.b. Ground compression modulus E’s depending on the modified Proctor density of soil and Hp for underground water level above pipe.

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6. Static calculations for PE and PP pipelines 6.10. Modified Proctor Density versus Standard Proctor Density One of parameters defining foundation conditions that may be selected in the program is Modified Proctor Density (MPD). Its value is slightly smaller in comparison with Standard Proctor Density (SPD), however, no direct and clear quantitative relation exists between these two numbers.

This relation is closely connected with type of soil. In common practice, for non-cohesive soil used for pipeline foundations, Modified Proctor Density constitutes reliable parameter to define mechanical properties of soil.

Table 6.10.a. Values of Standard Proctor Density and relevant values of Modified Proctor Density

Methods for ground compaction are shown in Table 6.10.b (for details see Table 8.7.b)

Max. layer thickness Type of equipment

Weight [kg]

90 %

0,10

1

3

0,30

0,20-0,25

1

3

0,15 0,20 0,40

0,20

1

4

Loam, clay, silt

Min. 15

0,15

Vibratory compactor

50-100

Dust vibrator

50-100 100-200 400-600

Modified Proctor Density

88

85

Manual tamper

93

90

Number of cycles 85 %

Gravel, sand

Standard Proctor Density

SOURCE: Design and installation of outdoor plastic systems, Wavin 1991

In order to obtain proper value of Modified Proctor Density for pipe backfilling, with particular consideration given to the sub-base zone, it is necessary to choose appropriate type of soil, thickness of compacted layers and suitable compacter equipment.

of Modified Proctor of Modified Proctor Density Density

6.11. Buckling External pressure (generated by soil and underground water) that generates circumferential compressive stress in the pipe wall may lead to buckling damages of pipe. Buckling risk depends on external pressure (Hp and h), possible negative pressure inside the pipe, pipe ring stiffness and type of soil.

As regards pipes laid in grounds with relatively high and uniform compaction, risk of buckling is small.

Permissible (critical) load can be calculated using the following formula:

For pipes with low ring stiffness, laid down in shallow trenches (Hp < 1.5 m) and subjected to vehicular traffic loads, the following formula is additionally used:

(9)

qdop =

64 . SR _____________ 3 1+3,5. D_δ__ m

Short-term pipe ring stiffness should be used here.

Dimensioning criteria are: short-term relative deflection and critical pressure causing buckling.

(8)

qdop =

5,63 . _____ F

δ 1-3. ___ . SRI . E't Dm

Diagram 6.11.a. Resistance to buckling as a function of ring stiffness of a pipe q Buckling (kN/m2)

where: F - factor of safety, here F = 2 E’t - ground deformation modulus, here E’t = 2E’s δ/Dm - total relative pipe deflection Long-term pipe ring stiffness SRl = 0,25 SR was assumed in this formula.

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well compacted soil non-compacted soil

e without buckling of the pip ground the support of the Ring stiffness (kN/m2)

6. Static calculations for PE and PP pipelines 6.12. Maximum short-term deflection Recommended maximum short-term deflection is 6%. This value includes considerable margin for unpredictable effects resulting from operating conditions rather than from strength of pipe material.

Excessive pipe deflection and self-consolidation of the backfill soil may lead to surface damages. When tube jointing sleeves are used, excessive pipe deflection may result in unsealed joints.

Verification of permissible load is based on the formulas: - for Hp ≤ 1,5 m - formula (8) assuming long-term pipe ring stiffness SRl = 0,25SR and formula (9) when short-term pipe ring stiffness SRl is assumed.

Smaller permissible load of the two values calculated according to the above scheme is considered reliable value.

- for Hp > 1,5 m – formula (8) assuming long-term pipe ring stiffness SRl = 0,25SR For thermoplastics pipes laid down in ground, buckling will rarely have decisive effect on load carrying capacity.

Gravity Systems – Manual | 2 3

7. Uponor Infra calculating software 7.1. Uponor Infra calculating software The Uponor Infra calculating software is designed to make static, strength and hydraulic calculations and consists of the following modules: Underground tank – calculation of stability against lift Sewer bottom manhole – calculation of stability against lift Underground pipeline – static calculations Pressure pipe – hydraulic calculations Gravity pipe – hydraulic calculations The software is available in three language versions: Polish, Russian and English.

Detail information on the assumptions and algorithms used in the calculating method for each individual module can be

Underground tank – calculation of stability against lift The module has been designed for calculating the stability of Uponor Infra-manufactured Weho tanks against lift. Total exerted lift and backfill weight is calculated for specified soil and water conditions. If, due to the lift, it is necessary to anchor the tank, the software calculates the foundation parameters, an appropriate number of anchors and the value of force in an anchor cable.

Sewer bottom manhole – calculation of stability against lift The module has been designed for calculating the stability of Uponor Infra-manufactured Weho sewer bottom manholes against lift. In order to calculate the stability of a sewage manhole for specified soil and water conditions, the software compares the design value of hydrostatic lift exerted on the manhole with the sum of values of the bearing forces (tare weight and friction of soil against external lateral surface of the manhole). If the condition for the manhole stability against lift is not met, the software determines appropriate parameters for a loading chamber filled with concrete, which is later placed in the bottom part of the manhole.

2 4 | Gravity Systems – Manual

found in the Help/Technical Specifications Menu.

All rights to the software are reserved. Uponor Infra bears no responsibility or liability for any damage or consequences resulting from the use of the calculating software. Should you have any questions or comments regarding the software, please contact Uponor Infra.

The latest version of the software can be downloaded and installed from www.uponor.pl/infra

7. Uponor Infra calculating software Underground pipeline – static calculations The module is designed for strength dimensioning of polyethylene pipes (PEHD) and polypropylene pipes (PP) offered by Uponor Infra.

The module allows the user to select the right type of pipe (in terms of diameter and ring stiffness) for given conditions of installation including transportation loads. The algorithm was developed on the basis of the Scandinavian Method.

Pressure pipe – hydraulic calculations The module is designed for hydraulic dimensioning of polyethylene (PEHD) pipes Wehopipe offered

by Uponor Infra and it refers to pressure pipelines.

The module allows the user to calculate one of the following parameters: the diameter, the value of energy needed or lost for a given type of pipe and the specified medium parameters.

Gravity pipe – hydraulic calculations This module is designed for hydraulic dimensioning of polyethylene pipes (PEHD) and polypropylene pipes (PP) offered by Uponor Infra and it refers to gravity pipes.

It allows the user to choose appropriate values of inside diameter, pipe bottom gradient, section filling rate or flow rate determination for a given type of pipe and the specified medium parameters.

Gravity Systems – Manual | 2 5

8. Laying gravity pipelines in the ground 8.1. Soil classification Table 8.1.a Classification of soil used for pipe-laying according to Standard ENV 1046:2001

Group of soils Type of soil

#

1

Typical description

Symbol*

Gravel, gap graining

(GE) [GU]

Gravel, continuous grading Well graded aggregate

[GW]

Characteristics

Example

Steep grain-size distribution curve, domination of one fraction

Crushed stone, valley and beach gravel, glacial gravel

Smooth grain-size distribution curve, several fractions

(Gl) [GP]

Stepped grain-size curve, certain fractions missing

(SE) [SU]

Steep grain-size distribution curve, domination of one fraction

loose Sand, gap grading 2

Sand, continuous grading, well graded aggregate Well graded aggregate Loam gravel, gap grained loam aggregate

loose

3

[SW] (Sl) [SP]

Dune sands, deposited sands, sands from valleys and troughs

[GC] (GT)

Gap grained, contains fine clay fraction

Loam sand, gap grained sandclay mix

[SM] (SU)

Gap grained, contains fine loam

Watered sand, clay sand, sand loess

Clay sand, gap grained sandclay mix

[SC] (ST)

Gap grained, contains fine clay

Clay sand, alluvial clay, marl

Inorganic loam, fine sand, stone dust, clay and loam sand

[ML] (UL)

Poor stability, quick mechanical reaction, plasticity zero to small

Loess, sand clay

[CL] (TA) CTL) (TM)

Stability medium to very good, mechanical reaction not very fast, plasticity poor to medium

Alluvial marl, clay

Vegetable and non-vegetable matter, putrefactive stench, low volumetric weight, high porosity

Humus, chalk sand, tuff

[OL] (OU)

Medium stability, mechanical reaction slow to very fast, plasticity low to medium

Sea chalk, humus

[OH] (OT)

High stability, no mechanical reaction, plasticity medium to high

Silt, moulder’s loam

Organic loam and organic clay-loam mix Organic clay, clay with organic matter Peat, and other highly organic soils

[OK]

[Pt] (HN) (HZ)

6 Silt

[H]

Weathered gravel, rock waste, clay gravel YES

YES

NO

Decomposing peat, fibrous, colours Peat from brown to black Sludge deposited at the bottom of water-course, often mixed with sand/clay/chalk, very soft

NO Silt

* Symbols are taken from two sources. Symbols in square brackets [..] are from British Standard BS 5930.

Symbols in round brackets (..) are from German Standard DIN 18196 .

If subgrade is a mix of several kinds of soil, one component may be used as a basis for classification.

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YES

Glacial, terrace and shoreface sands

Clay gravel, well graded gap grained loam aggregate

Multi-fractional loose soil with humus

organic

scoria, volcanic dust

Gap grained, contains loam fraction

Inorganic clay, clay of high plasticity

5

Stepped grain-size curve, certain fractions missing

YES

[GM] (GU)

coherent 4

organic

Smooth grain-size distribution curve, several fractions

Możliwość użycia do zasypki

8. Laying gravity pipelines in the ground Table 8.1.b. Classification of mineral soils

Name of soil

Symbol

Sub-type

Fraction [mm]

Loam

I

<0,002

Clay

G

Dusty clay Clay Sandy clay

0,002 - 0,006 0,006 - 0,02 0,02 - 0,06

Sand

P

Fine sand Medium sand Coarse sand

0,06 - 0,2 0,2 - 0,6 0,5 - 2,0

Gravel

Ĺź

Fine gravel Medium gravel Coarse gravel

2,0 - 6,0 6,0 - 20,0 20,0 - 60,0

8.2. Trench construction Open trench without boarding a. Open trench, sloping walls without boards In case of trenches up to 4.0 m deep with no underground water and without land slips, with no load on surcharge within reach of soil wedge, the following safe sloping is allowed: Table 8.2.a Slopes in open trench without boarding.

Permissible slope in open trench without boarding Type of soil

Max. slope H:x

Highly cohesive

2:1

Rocky

1:1

Other cohesive soils

1:1.25

Non-cohesive

1:1.5

For other cases sloping should be indicated in the engineering design

Fig. 8.2.a. Sectional view of open trench without boarding

b. Open trench with vertical walls without boardingSuch trench is allowed in a dry soil only provided the ground is not under the load of a bank or construction equipment located near trench edges at a distance less than one trench depth H. Excavated material should be stored at least 0.5 m away from trench edges while the damp must not present any risk to stability of the trench walls.

Table 8.2.b. Vertical wall trench depth without boarding

Permissible depth of vertical wall trench without boarding Type of soil

Max. trench depth H

Solid rocky ground without cracks

4.0 m

Cohesive soils

1.5 m

Other soils

1.0 m Fig. 8.2.b. Sectional view of vertical wall trench without boarding

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8. Laying gravity pipelines in the ground Open trenches with supported vertical walls Trench walls should be protected exactly as required by engineering design. Particular precautions should be taken when trench is situated near public road or a building.

where:

Distance from a road Road traffic may proceed at a distance not smaller that that calculated according to the following formula:

h

b≥H / tgΦu + 0.5

where: b - distance between edge of roadway and edge of trench [m] H - trench depth Φu - soil internal friction angle

a

- distance between trench bottom edge and vertical foundation

wall of a building founded above trench bottom level H,

Φu -

see the formula above

- Depth of foundation of the neighbouring building from ground level to building foundation level

If these distances can not be maintained, safety of trench boarding and of neighbouring road or building should be analyzed in detail.

In this case boarding should be left in the trench and the soil inside trench should be thoroughly compacted to fulfil the requirements given in documentation.

Distance from building (foundation) For buildings founded above bottom level distance between trench bottom edge and vertical foundation wall should not be smaller than: a ≥ (H - h + 0.3) / tgΦu + 0.5

Fig. 8.2.c Sectional view of a trench with supported walls

Minimum distance between two neighbouring vertical supported trenches.

Last layer of soil 0.2 m thick at trench bottom should be If two trenches are adjacent one to another, minimum distance removed directly before laying a pipeline, taking particular between their inner edges may not be smaller than: attention to pipeline foundation level– making the trench excessively deep is not allowed. d ≥ (H - 1) / tgΦu where: H - depth of deeper trench from ground level to trench bottom level Φu - soil internal friction angle.

ZIt is recommended to make deeper trench first. Other conditions for making safe trenches are described in Standard BN-83/8836-02.

8.3. Terminology

Fig. 8.2.d. Cross section of two neighbouring supported trenches

Table 8.3.a. Minimum distance between pipe and trench slope depending on pipe diameter

Minimum bs values

Fig.8.3.a. Sectional view of a trench for laying a pipeline

1. Subgrade (bottom backfill) 2. Main backfill 3. Upper backfill 4. Top charge

5. Virgin soil H – Trench depth b – Trench width Hz – Cover thickness

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de [mm]

bs [mm]

de < 300

200

300 < de < 900

300

900 < de < 1600

400

1600 < de < 2400

600

2400 < de < 3000

900

Trench width at pipe limiting outline level should not exceed necessary pipe in consideration of the method for pipe joining (welding, socket connectors, etc.) and with allowance for additional space for compaction of backfilling material. Wider trenches may be necessary when pipes are laid deep or in cases of poor stability of unprotected walls.

8. Laying gravity pipelines in the ground 8.4. Method for installation of pipelines in the ground Determination of soil conditions is crucial for engineering design that precedes earth work and laying a pipeline in the ground (1) Subgrade: soil compacted to approx. 90 – 95% SPD Layer of approx. 100-150 mm, gravel, sand, well graded aggregate, loam, clay (group 1 – 4 in the table), manual compaction.

Pipes should be laid down at the trench bottom so that they evenly rest on subgrade along their entire length.

Strength of subgrade may not be less than assumed in the engineering design (static calculations of pipeline). Moreover, hydraulic gradient should be ensured.

1

Fig. 8.4.a Preparation of subgrade

Main backfill (2) and upper backfill (3): soil compacted to approx. 90 – 95% SPD Backfill should be symmetrical at both sides of pipe in layers not exceeding 0.2 m, paying particular attention to careful compaction of soil in pipe support zone. It is necessary to ensure that pipe would not go up during compacting operation. Use of light vibratory equipment (weight up to 100kg) is recommended. Use of the compactor directly above pipeline is not allowed. This may be used only when the cover is at least 0.3 m thick.

For the first layer - up to 0.3 m thick - material belonging to group 1-4 with granularity specified in Table 8.4.a should be used.

3 2

Fig. 8.4.b. Main and upper backfills

Virgin soil may be used for backfilling in the pipe foundation zone provided it satisfies all the criteria given below:

Table 8.4.a. Required granulation of soil

System

Nominal diameter of pipe

Maximum particle size

WehoDuo WehoTripla

DN ≤ 100 100 < DN ≤ 300 300 < DN ≤ 400

15 20 30

Weholite (pipes, manholes, tanks, fittings)

300 < DN ≤ 600 600 < DN ≤ 1600 1600 < DN ≤ 3000

30 40 50

a) does not contain particles larger than allowed for given pipe diameter as per Table 8.4.a; b) does not contain lumps larger than double size of particles for specific application as shown in Table 8.4.a; c) if the material is not frozen; d) does not contain foreign matter (such as asphalt, bottles, cans, pieces of wood) e) if compaction using flexible material is required If no detailed information about original material is available, density factor of 91 to 97% acc. to Standard Proctor Density (SPD) is assumed.

Gravity Systems – Manual | 2 9

8. Laying gravity pipelines in the ground (4) Backfill The green belt: If a pipeline is laid down in the green belt area, virgin soil (from excavation) may used provided it belongs to group 1 â&#x20AC;&#x201C; 4. In this case it should be compacted to approx. 88% SPD.

Excavations under the streets: Virgin soil may used for backfilling. Vibratory equipment with weight of up to 200 kg may be used. Density according to SPD should satisfy the requirements for road construction.

For pipelines laid under streets frost heave soils may not be used as upper layer of backfill (thickness depending on frost penetration conditions).

4

4

Fig. 8.4.c. Sectional view of a trench made in the green belt area

Fig. 8.4.d. Sectional view of a trench made under street

8.5. Excavation water drainage Lowering of the water table in trench should be done if excavation work or laying the pipelines is hindered by underground water. Lowering of the water table should be done without disturbing subgrade soil structure or subgrade soil of neighbouring buildings. Underground water table should be lowered by minimum 0.5 m below the trench bottom. Due to harmful effect of water table variations on the trench bottom soil structure, lowering of the underground water table should include 24-hour periods. Moreover, excavated trench should be protected against inflow of rain water. Structures protecting trench walls should stand out at least 0.15 m above the adjacent ground, while ground surface should be suitably sloped for easier water removal.

Any loose ground (dewatered for the time of construction) without grains exceeding 20 mm (not more than 16 mm in case of crushed stone) or cohesive soil satisfying the requirements for grounds with symbols ms, ss, zs

according to PN-B-02481 may be used as subgrade for the pipeline. Strength parameters of subgrade may not be worse than assumed in the design documentation (static calculations for the pipeline). If cohesive soil occurs at the trench bottom, a layer of loose ground backfill not less than 0.15 m thick and not less than 0.25 pipe diameter should be made before the pipeline is laid down. This backfill should be compacted up to 95% SPD. Pumping of underground water may be stopped only when the pipeline is completely backfilled. Civil engineering design must describe detailed method for trench dewatering.

8.6. Selection of pipe stiffness for the type of ground Type of ground and degree of its compaction are crucial factors in construction of gravity pipelines.

top charge upper backfill

1 2

main backfill b

Fig. 8.6.a. Division of trench into zones of virgin soil (2) and the ground around pipeline (1)

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Fig. 8.6.b. Layers of soil with different density

subgrade (bottom backfill)

8. Laying gravity pipelines in the ground Selected pipe stiffness should be verified by static calculations (e.g. according to Scandinavian Method). In general, it is assumed that the trench is dewatered prior to installation. If underground water is present, allowance for additional pipe load should be made in pipeline calculations.

In general, selection of pipe stiffness depends on the type of virgin soil, top charge material and its density, thickness of

cover above pipe, water table, size and geometry of load as well as the boundary values for given pipe.

Matching pipeline stiffness with installation conditions should be agreed with the designer. Tables below show general values of ring stiffness relative to given ground properties

Table 8.6.a. Recommended minimum stiffness for pipes laid in ground not exposed to traffic generated loads

Pipe stiffness [kN/m2] Backfill material [Group]

Class of density

1 1 2 3 4

1 m < Thickness of cover < 3 m

2

Virgin soil group 1

2

3

4

5*

6*

W M W M W M W M

4 4

4 4 4 4

4 4 4 4 4 8

4 4 4 8 8 8 8 **

4 8 8 8 8 8 8 **

8 8 8 8 8 ** 8 **

W M W M W M W M

4 4

4 4 4 8

8 8 8 8 8 ** ** **

8 8 8 ** ** ** ** **

3 m < Thickness of cover < 6 m 1 2 3 4

4 4 4 8 8 **

4 8 8 8 8 ** ** **

*) In grounds with low carrying capacity, pipe foundation should be reinforced e.g. with geotextiles (see paragraph 8.12.) **) Static calculations are necessary for determination of geometry of trench and pipe stiffness.

Table 8.6.a. Recommended minimum stiffness for pipes laid in ground subjected to traffic generated loads

Pipe stiffness [kN/m2] Backfill material [Group]

1 m < Thickness of cover < 3 m

Class of density

1 1

W

2

W

3

W

4

W

1

W

2

W

3

W

4

W

2

Virgin soil group

1

2

3

4

5*

6*

4

4

8

8

8

**

8

8

8

**

**

8

**

**

**

**

**

** 8

3 m < Thickness of cover < 6 m 4

4

4

8

8

4

4

8

8

8

8

8

8

**

**

**

**

*) In grounds with low carrying capacity pipe foundation should be reinforced e.g. with geotextiles (see paragraph 8.12.) **) Static calculations are necessary for determination of geometry of trench and pipe stiffness.

In addition, when pipeline is laid under unsurfaced road (particularly if depth is small) pipeline may be covered with reinforced slabs for greater safety.

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8. Laying gravity pipelines in the ground 8.7. Recommended methods for soil compaction Strength of the backfilled zone depends on type of soil used for backfilling as well as its density after compaction. Degree of compaction depends the equipment used and the number of layers. Degrees of soil compaction as defined by Standard Proctor Density (SPD) achieved in three classes, that is “W”, “M” and “N” depending on type of soil used, are shown in Table 8.7.a.

Recommended maximum thickness of layer and number of runs necessary to obtain required density for various equipment and material (soil group) for backfilling are given in Table 8.7.b.

Also minimum thickness of layer above the pipe top where particular equipment may be used for compacting soil directly above the pipe.

Data shown in Table 8.7.b. are for general information only and detailed method for soil compaction should be discussed with the designer and the contractor.

Table 8.7.a. Degrees of soil compaction according to Standard Proctor Density (SPD) for individual classes of density. SPD densities were determined according to DIN18127.

Class of density No compaction M medium compaction W high compaction

Soil group used for backfilling 4 SPD [%]

3 SPD [%]

2 SPD [%]

1 SPD [%]

75 ÷ 80

79 ÷ 85

84 ÷ 89

90 ÷ 94

81 ÷ 89

86 ÷ 92

90 ÷ 95

95 ÷ 97

90 ÷ 95

93 ÷ 96

96 ÷ 100

98 ÷ 100

Table 8.7.b. Recommended thickness of layer and number of runs during soil compacting

Equipment

No. of runs for particular class of density

Maximum layer thickness after compacting [m] for individual groups Minimum thickness of soil of layer above pipe, before compacting [m] 1 2 3 4

Density “W” (high)

Density “M” (medium)

Treading down or manual rammer min. 15 kg

3

1

0,15

0,10

0,10

0,10

0,20

Vibratory compactor min. 70 kg

3

1

0,30

0,25

0,20

0,15

0,30

Flat compactor min. 50 kg min. 100 kg min. 200 kg min. 400 kg min. 600 kg

4 4 4 4 4

1 1 1 1 1

0,10 0,15 0,20 0,30 0,40

— 0,10 0,15 0,25 0,30

— — 0,10 0,15 0,20

— — — 0,10 0,15

0,15 0,15 0,20 0,30 0,50

Vibrating roll min. 15 kN/m min. 30 kN/m min. 45 kN/m min. 60 kN/m

6 6 6 6

2 2 2 2

0,35 0,60 1,00 1,50

0,25 0,50 0,75 1,10

0,20 0,30 0,40 0,60

— — — —

0,60 1,20 1,80 2,40

Double vibrating roller min. 5 kN/m min. 10 kN/m min. 20 kN/m min. 30 kN/m

6 6 6 6

2 2 2 2

0,15 0,25 0,35 0,50

0,10 0,20 0,30 0,40

— 0,15 0,20 0,30

— — — —

0,20 0,45 0,60 0,85

6

2

0,25

0,20

0,20

—

1,00

Heavy three-wheeled roller (without vibration) min. 50 kN/m

Verification of compacting quality Conformity with the engineering design should be ensured using at least one of the following methods: - rigorous supervision of compacting procedures - verification of initial deflection of the installed pipe - examination of soil consolidation at construction site 3 2 | Gravity Systems – Manual

After the equipment was repaired or started again it is necessary to ensure that loose material being transferred and the material used for backfilling is compacted more or less to the same degree as the soil adjacent to the earth work.

8. Laying gravity pipelines in the ground 8.8. Pipe laying work in low temperatures Frozen soil may be found in trench bottom when laying pipes in low temperatures. Laying pipes on the layer of frozen soil is not allowed. Immediately before laying the pipeline frozen soil has to be removed and replaced with fresh, loose ground with granularity of up to 20 mm (up to 16 mm in case of crushed stone). This layer should be compacted to density of 95% SPD. It is not allowed to backfill the trench with soil containing frozen lumps.

When pipes are joined by extrusion welding during winter season or in rain, joining spot should be covered with tarpaulin or a tent.

8.9. Removal of trench boarding When distance between edge of a trench and public road or building (as defined in BN-83/8836-02) is too short, it may be necessary to leave boarding inside the trench. In other cases boarding should be removed. Boarding, steel sections or box type shuttering should be removed with trench backfilling. The advantage of box type shuttering is that it does not produce any risk to the neighbouring buildings (no ground vibration generated as compared to pile driving) and ensures that soil density is maintained. Moreover, shuttering of this type provide for safety of work. Pulling shuttering elements out may lead to loosened backfilling material. This results in reduced carrying capacity and damaged road surface as a result of additional settlement of the backfill soil. Consequently, it is recommended to increase density of backfilling material to 97% SPD in order to reduce unfavourable effects of pulling the shuttering elements out, particularly concerning pipelines laid under street surface.

8.10. Parallel pipelines When pipes are laid in parallel in ordinary trench, sufficient distance should be maintained between them so that necessary space is left for the compacting equipment. Width of free space should exceed that of compacting equipment by 150 mm. Density of compacted backfill material between pipes should be identical to that between pipe and the trench wall.

When parallel pipes are laid in stepped trenches (see Figs.

8.10.a and 8.10.b), backfill material should be loose with density class W. 1

b 1- highly compacted soil (class W) 1

Fig. 8.10.a Parallel pipes inside stepped trench

b-space for soil compacting equipment Fig. 8.10.b Parallel pipes inside even trench

Gravity Systems â&#x20AC;&#x201C; Manual | 3 3

8. Laying gravity pipelines in the ground 8.11. Replacement of soil considered individually basing on professional experience.

If soil is to be replaced involving unplanned additional deepening of the trench, the same material should be used for subgrade and the backfill and it should be compacted density of class “W”.

If rocks, stones or hard soil are found it is necessary to exchange soil at the trench bottom. Running sand, organic soils and soils with tendency to change volume when damp may appear. In such instances project engineer has to take decision on the extent of soil exchange under the pipe and how to found the pipe on the new soil. Each case must be

8.12 Pipeline installation in grounds with low carrying capacity If pipeline is to be laid on very weak ground such as peat or thick layer of mud, use of special method for laying is necessary.

The following procedure is possible: weak soil is strengthened or pipeline laid down on wooden framework.

Correct solution depends on the local conditions and requires individually designed supporting structure (or reinforcement of soil) as well as separate static calculations of pipeline considering new foundation method.

Other special conditions during pipe laying may include underground water (flowing or standing) appearing at the trench bottom or running sand effects. In such cases pumping wells or drain pipes are installed to lower underground water table. They are installed during pipe laying work and are operated until the pipe is covered with layer of soil sufficient to counteract hydrostatic lift or trench wall failures. Soil granularity in the subgrade and backfill zones should be selected correctly to prevent migration of fine fractions between excavation area and the adjacent ground.

Any migration of soil grains between zones may lead to weakened bottom and side supports of the pipe.

Use of suitable filtering mats may prevent transport of fine fractions of soil. If filtering mats are composed of many pieces, an overlap not less than 0.3 m wide is necessary. One-piece mats should be laid with an overlap of not less than 0.5 m.

If low carrying capacity ground appears at pipeline foundation level, the following procedure is necessary: - when thin layer of weak soil is deposited at the trench bottom, this soil should be replaced with loose ground with granularity of 20 mm (16 mm if crushed stone is used). Layer of the replaced soil should be compacted to 95% SPD minimum.

- when thick layer of weak soil is deposited at the trench bottom, a layer of minimum 0.35 m should be removed (the weaker is the ground the thicker layer has to be removed) and less than 0.25 pipe outside diameter. Then, layer of gravel or crushed stone not less than 0.2 m thick with granularity of 2 – 32 mm should be laid. This layer should be compacted to 95% SPD minimum.

When very weak cohesive soil is deposited at the trench bottom it is recommended to use geotextile mats in the area of exchanged soil to avoid mixing of virgin soil with reinforcement layers and for additional subgrade strengthening. The fabric should be laid on virgin soil.

Moreover, geotextile mat may be used for: - protection of backfilling material against mixing with virgin sol and for protection of the backfill against loosening caused by pulling the sheet piling out.

- anchoring pipeline to prevent it from coming up to the surface - increasing load carrying capacity of subgrade and to reduce uneven pipe settlement

1

1

1 2

1

2

3

2

2

3

3

3

Legend: 1 Backfill zone 2 Subgrade 3 Filtering mat

Legend: 1 Backfill zone 2 Subgrade 3 Wooden framework

Fig. 8.12.a. Protection against migration of fine fractions of soil

Fig. 8.12.b. Trench bottom reinforced with wooden framework

3 4 | Gravity Systems – Manual

8. Laying gravity pipelines in the ground Geotextiles If safe work in the trench is not possible due to excessively weak or soft ground, trench bottom should be reinforced prior

to making subgrade. Wooden structure or geotextile mat may be used as shown in Figs 8.12.

Typical applications of geotextile mats Fig. 8.12.c. Geotextile mat reducing uneven settlement of pipe foundation zone

1

1

Fig. 8.12.d. Geotextile mat constituting partial ground sill, shuttering and reinforcement

1

1

1

Fig. 8.12.e. Geotextile mat constituting full ground sill, shuttering and reinforcement

1

1

1

1

Fig. 8.12.f. Geotextile mat constituting anchorage preventing the pipe from uplifting

1

1

1

1 – geotextile mats 8.13. PE pipes used for drainage purposes WehoDuo Drain pipes are used for drainage. For easier pipeline installation it is recommended to use Uponor Infra inspection chambers and intake manholes. These pipes are suitable for all drainage systems for long lasting or temporary lowering of underground water table (regular drainage systems, drainage of individual structures, removal of water from excavations) as well as for removing liquids flowing away from municipal and industrial waste dumps. Important advantage of WehoDuo Drain pipes used in drainage systems which are usually carrying some sand is their high abrasion resistance.

Execution of each drainage system should be preceded by hydraulic and static calculations. Such calculations are particularly important in case of rubbish dumps, where significant pipeline loads may occur. Concrete aggregate (rinsed out) may be used as backfilling material satisfying the requirements of Polish Standard PN-86/B-06712.

Granularity should be up to 8 mm with fractions Φ< 0.02 mm nor exceeding 3% and Φ<0.063 mm not exceeding 10% by weight. Thickness of backfill around the pipe should conform to engineering design and should not be less than 0.15 m.

Gravity Systems – Manual | 3 5

8. Laying gravity pipelines in the ground 8.14. Gravity pipe wall passes 1

Weholite pass through concrete wall

2

This anchor wall pass remains tight up to 3 m column of water provided “Frank System” rubber sleeves are used. In addition, the wall must be made of watertight concrete.

L

di

de

4

do

1. Partition – watertight concrete 2. PE anchor flange 3. Frank rubber sleeve 4. Weholite pipe

3

Fig. 8.14.a. Diagrammatic of Weholite wall pass

Table 8.14.a. Dimensions of Weholite wall passes

dn=di

L

de *

do

Frank rubber flange

mm

mm

mm

mm

Zakres dn

Frank profile

300

800

341

531

315-354

A

350

800

406

596

400-449

B

400

800

455

645

450-499

B

450

800

511

702

500-559

B

500

800

569

758

560-629

B

600

800

679

862

630-709

B

700

800

793

977

710-799

B

800

800

907

1191

800-899

B

900

800

1016

1303

1000-1150

B

1000

800

1130

1416

1000-1150

B

1050

1000

1190

1467

1000-1150

B

1200

1000

1355

1629

1200-1350

B

* for SN8 ring stiffness

Fig. 8.14.b. Frank System rubber sleeve – Profile A dn=90÷315 mm

Fig. 8.14.c.Frank System rubber sleeve – Profile B dn=355÷1200 mm

3 6 | Gravity Systems – Manual

60

1

1

37,5

dn

dn 60

1

37,5

60

60

1

dn

using “Frank System” sealing sleeves (profile A or B) – depending on conduit diameter.

dn

Frank Type rubber sealing sleeves Sleeve may be installed on Weho pipe in any location.

Depending on design specification length L may differ from that given in the Table. Additional tightness my be obtained

75

75

8. Laying gravity pipelines in the ground WehoDuo pass through concrete wall The proposed anchor transition is tight up to 3m of water in the condition of the application of the Frank rubber flanges 1 watertight system. Additionally concrete wall must be made of L concrete.

2

Fig. 8.14.d. Diagrammatic of WehoDuo wall pass 1

1

2

2

3

4

do

L

3 4

di

* The length of anchoring flange for WehoDuo pipes is adjusted individually to the specific project solution.

di

de

di do

de

4

do

1. Partition – watertight concrete 2. PE anchor flange 3. Frank rubber sleeve 4. WehoDuo pipe

3

de

L

Table 8.14.b. Dimentions of WehoDuo OD, WehoTripla wall pass

WehoDuo OD

110-121 160-180 200-224 250-279 315-354 400-449

WehoTripla concrete wall pass

L

Fig. 8.14.e. Diagrammatic view of WehoTripla wall pass

1. Partition – watertight concrete 2. PE anchor flange 3. Sealing 4. WehoTripla pipe

+ + + + + +

WehoTripla do [mm] 129 180 219 272 338 428

L

L 110; 240 110; 240 240 240 240 240

1 2

2

3

3

4

4

di

de

L*

1

It is recommended that wall is made of watertight concrete. do

dn=de [mm] 110 160 200 250 315 400

di

Frank rubber flange

Frank profile A A A A A B

de

do [mm] 210 260 340 390 455 500

do

dn=de [mm] 110 160 200 250 315 400

8.15. Connections with rigid structures When a pipeline is passed through buildings, drains or retaining walls allowance for differences in settlement should be made while designing connections.

Such materials as polyethylene are flexible enough to take existing displacements and may be connected as shown in Fig. 8.15.a. Pipes projecting from rigid structures should be effectively supported by the subgrade to minimize stresses caused by shearing forces and bending moments.

Legend: 1. Backfilling material – well compacted (class W) 2. Virgin soil 3. Pipe 4. Fitting – wall pass

5 4 1

3

2

Fig. 8.15.a. Diagrammatic view of connection of gravity pipeline with concrete wall

Gravity Systems – Manual | 3 7

8. Laying gravity pipelines in the ground 8.16. In-situ connections with existing Weho collector/ manhole Table 8.16.a. Dimensions of In-Situ connections

WehoTripla WehoDuo OD pipe diameter

Hole diameter

dn [mm]

d1 [mm]

110 160 200 250 315

138 186 226 276 341

Rys. 8.16.a. In-Situ connections

In-Situ connector should be used for making connection with Weholite collector or Weho manhole.

Proceed as follows:

1. Define connection diameter

2. Cut suitable hole in the Weholite pipe wall

3. Place In-Situ connector in the hole

4. Insert connection pipe in the rubber In-Situ connector

Required tools: - Electric drill â&#x20AC;&#x201C; power app. 2 kW - Circle cutter according to In-Situ hole diameter (available from Uponor Infra) 3 8 | Gravity Systems â&#x20AC;&#x201C; Manual

9. Gravity pipe connections 9.1. Types of pipe connectors manufactured by Uponor Infra Table 9.1.a. Types of pipe connectors and respective diameters of Uponor Infra gravity pipelines

Type of pipe

Type of connection

110

WehoTripla (dn 110-400)

Socket Double socket

110

400

All connections

WehoDuo OD (dn 110-400)

Socket Double socket

110

400

All connections

Socket Double socket

Diameter range

300

Snap-joint

3000

Quick and durable connection, may be disconnected if necessary

1000

600

In difficult conditions of wet trench, snapjoints factory mounted

1200

Weholite (dn300-3000) Screw joint Extrusion welding

350 300

Application

Road culverts; renovations â&#x20AC;&#x201C; tightness due to extrusion welding from outside

1200 3000

Connections inside or outside trench, dry conditions

Gravity Systems â&#x20AC;&#x201C; Manual | 3 9

9. Gravity pipe connections 9.2. WehoTripla socket connections

1) Thoroughly clean all dirt off pipe socket

2) Check if the seal is mounted properly

3) Coat the pipe end with lubricant

Single- or double socket connections may be used for WehoTripla pipes

4) P lace the pipe end in the socket.

Be careful to align both parts coaxially and make sure that seal does not turn around during assembly

Table 9.2.a. Dimensions of single- and double socket connections for the WehoTripla pipes

Single socket connections for WehoTripla pipes Lw [mm] 57 80 100 135 148 158

dn=de [mm] 110 160 200 250 315 400

Single socket connection

5) T he pipe may be pressed down using hand tools

Double socket connection Lw

Lw

Lw

de

de

Lw

de

Lw

Lw [mm] 65 85 105 133 143 155

de

dn=de [mm] 110 160 200 250 315 400

Double socket connections for WehoTripla pipes

9.3. WehoDuo OD socket connections

2) Place seal between two first ridges of the pipe

1) Thoroughly clean all dirt off pipe socket

3) Clean all dirt off the pipe and coat the pipe end with lubricant

4) Coat the pipe socket with lubricant

Single- or double socket connections may be used for WehoDuo OD pipes Table 9.3.a. Dimensions of single- and double socket connections for the WehoDuo OD pipes Single- and double socket connections for WehoDuo OD pipes dn=de [mm] 110 160 200 250 315 400

Lw [mm] 60 70 76 100 140 134

Lw

4 0 | Gravity Systems â&#x20AC;&#x201C; Manual

Lw

de

Schematic view of connection

5) Push the pipe end into socket

9. Gravity pipe connections 9.4. Weholite socket connections Assembly of Weholite double socket connections is the same as for WehoTripla and WehoDuo pipes. Seal is fitted inside socket.

dn=di [mm] 300 350 400 450 500 600 700 800 900 1000

d2 [mm] 391 456 509 568 622 735 868 980 1085 1200

Ldk [mm] 291 315 355 385 455 487 535 595 708 730

L3 [mm] 138 150 160 185 220 236 260 290 347 358

L1 [mm] 70 70 70 85 90 94 110 110 110 110

L2 [mm] 138 150 160 185 220 236 260 290 332 343

d2

L3

dn

Ldk

Table 9.4.a. Dimensions of double socket connections for Weholite pipes

Schematic view of connection of Weholite socket and double-socket

9.5. Weholite Snap-Joint connections Force F required to make this connection varies depending on pipe diameter. Snap on terminal is factory fitted on the pipe end. Snap-Joint connection is a permanent joint.

Snap-Joint connection is used in trenches where water removal is very difficult. Before connection, pipes should be aligned coaxially and then one pipe end should be pushed into another with the use of excavator.

dn=di [mm] 600 700 800 900 1000 1200

L [mm] 183 197 198 199 198 198

Lc [mm] 215 227 230 230 230 230

View and cross section of the Snap-Joint connection

F [tony] 3÷3,5 3÷3,5 3÷3,5 3,5÷4 3,5÷4 3,5÷4

Lc L

di

Table 9.5.a. Dimensions of Snap-Joint connections for Weholite pipes

9.6. Weholite screw joints Screw joints are mainly used in relining operations. Pipes screwed together are resistant to axial tension. Screw joints are sand tight. Watertightness is achieved after addition extrusion welding from outside.

dn=di [mm] 350 400 450 500 600 700 800 900 1000 1200

L [mm] 111 124 128 154 184 223 260 260 308 343

di

L

Table 9.6.a. Dimensions of screw joint connections for Weholite pipes

Gravity Systems – Manual | 4 1

9. Gravity pipe connections 9.7. Weholite extrusion welding When welding with the use of extruder pipe ends are warmed up with hot air and then molten PE material is forced into the gap between pipe ends.

CROSS SECTION OF EXTRUSION WELDED CONNECTION PREPARATION

H1

EXTRUSION WELDING

Recommended welding tool: Munsh MA36 or MAK48 extruder

General guidelines for extrusion welding - Connection has to be made in dry conditions. Even minimum quantity of water may result in leaky connection.

- Joint has to be protected against wind (particularly in winter season and during rain) - Prior to joining operation pipe ends should be cleaned and suitably prepared: pipe ends should be bevelled as shown in the above picture. Pipe surface adjacent to the chamfer should be ground gently so that extrusion material is applied to fresh pipe surface.

- Since polyethylene can oxidize easily, bevelling and grinding operations should be done immediately before joining.

- In case of secondary soiling, dirty spot should be cleaned and ground again. o - Temperature of the PE rod should be 220 to 225 C.

4 2 | Gravity Systems â&#x20AC;&#x201C; Manual

- Extruder nozzle outlet air temperature should be in the o range from 230 to 260 C depending on ambient air temperature. During cold season blower air temperature should higher than during summer.

Required tools: - Extruder (e.g. manufactured by Munsh; extruder type according to specific requirement) - Electric saw with vertical blade app. 30 cm long - Drill - Power source 4kW, 230 VAC

9. Gravity pipe connections Depending on installation conditions (dimensions of the trench) Weholite pipes may be welded: 1. Extrusion welding method from the inside and from the outside (two-sided weld) Preparation of the pipe - After removal of impurities, ends of pipes should be bevelled from the inner and outer surface at an angle of 45° to a depth of H1 - The inner and outer surfaces of the pipe adjacent to the weld should be roughened by grinding.

Laying pipe in the trench - Prepared pipes lay in the trench with adjoing surfaces (optionally with a minimal slot), so that the fault of "Z" profile of both pipes adhere to each other and there is in the uppermost point of the circumference of the pipe

- In case of secondary soiling, dirty spot should be cleaned and ground again.

Extrusion welding - After completing all the preparation steps put joint inside and outside of the pipe by manual extruder (order is optional, depending on conditions on the building site).

The same process is performed to combine manhole stubs with collector.

NOTE: To perform the correct weld outside the pipe, it is necessary to provide a free space min. 1 m around the circumference of the pipe (installation hole).

Table 9.7.a. Parameters of welded joints.

Welding parameters for Weholite pipes Nominal Size DN=Di [mm]

Weld Two sided weld H1 [mm]

Two-sided welding (general values)

one sided weld (outside) H2 [mm]

PE rod / weld [kg]

Time of welding [h]

One-sided internal welding (use of steel band necessary) (general values) PE rod / weld [kg]

Time of welding [h]

800

6.0

13.5

2.0

2.5

3.5

4.0

900

6.5

15.0

2.0

2.5

3.5

4.0

1000

7.0

16.0

3.0

3.5

5.0

6.0

1050

7.0

16.5

3.0

3.5

5.0

6.0

1200

9.0

21.0

3.0

4.0

5.0

7.0

1400

10.0

23.0

4.0

5.0

7.0

8.0

1500

11.0

25.5

4.0

5.0

7.0

8.0

1600

11.5

26.5

5.0

6.0

8.5

10.0

1800

13.5

32.0

5.0

7.0

8.5

12.0

2000

14.0

32.5

6.0

8.5

10.0

15.0

Parameters of other diameters to be agreed with the manufacturer

2. Extrusion welding method from the inside (unilateral weld). This weld method is applied if there is no access to the pipeline from the outside.

Preparation of the pipe - After removal of impurities, ends of pipes should be bevelled from the inner surface at an angle of 30° degrees to a depth of H2 - The inner surface of the pipe adjacent to the weld should be roughened by grinding Laying pipe in the trench - Prepared pipes lay in the trench with adjoing surfaces (optionally with a minimal slot), so that the fault of "Z" profile of both pipes adhere to each other and there is in the uppermost point of the circumference of the pipe - In case of secondary soiling, dirty spot should be cleaned and ground again.

Extrusion welding - After completing all the preparation steps put multilayer joint inside of the pipe by manual extruder.

The same process is performed to combine manhole stubs with collector.

NOTE: - In the case of threats of moisture pipes prepared for the welding sealing band should be installed on the pipe ends.

- After the internal weld (and removing the sealing band) fault "Z" of both pipes should be welded from the outside.

9.8. Uponor Infra Service Group The Uponor Infra Company has its own Service Group responsible for making joints as well supervision of work to ensure correct installation of pipelines. Members of the Service Group are highly qualified Uponor Infra employees equipped with suitable tools: extruders and welding machines.

The Service Group is also authorized to train personnel in installation of PE pipelines and making joints directly at construction site as well as to issue certificates confirming participation in training course. Such certificate is often required during bidding to confirm qualifications of contractor’s personnel.

Gravity Systems – Manual | 4 3

10. Leak proof tests for gravity pipelines 10.1. Leak proof test of gravity pipelines (with flow caused by gravity) General The following components are subjected to water-pressure test at the construction site: - Gravity thermoplastics pipelines, in sections of limited length (e.g. between manholes); - Pipelines composed of Weholite pipes 1000 m long Maximum; - Weho manholes.

Tested pipeline is filled with clean water and pressurized with definite hydrostatic pressure. Leaktightness is assessed by measuring amount of water necessary to fill in for retaining required pressure or water level in the pipeline.

Table 10.1.a. Test pressure values relative to pipeline level and underground water table

Difference in height between pipeline axis and underground water table

Test pressure P01

a [m]

kPa

mm H2O

a<0

10.0

1000

0<a<0.5

15.5

1550

0.5<a<1.0

21.0

2100

1.0<a<1.5

26.5

2650

1.5<a<2.0

32.0

3200

2.0<a<2.5

37.5

3750

2.5<a<3.0

43.0

4300

3.0<a<3.5

48.5

4850

3.5<a<4.0

54.0

5400

4.0<a<4.5

59.5

5950

4.5<a<5.0

65.0

6500

Required minimum test pressure: P01 = 10 kPa = 0,1 bar = 1,0 m column of water If underground water is present, test pressure depends on the difference of levels between pipeline axis and underwater water table P02 = P01 + 1,1 x a (m column of water]) (2) where: P01 = 1,0 m column of water a = pressure exerted by underground water (m column of water)

NOTE: 100 kPa = 1 bar = 1 atm = 10 m column of water.

Temperature of water inside pipeline during test: Tmean = 20ºC +∆T; ∆T<10ºC (for gravity flow pipes) Temperature of leakage makeup water: Ta = Tmean ± 3ºC

Hydraulic test procedure acc. to SFS 3113:E

Test pressure or water level increased to: Phase I:

Pe1 = 1,0 + 1,1 a (column of water) Prior to starting Phase II maintain pressure Pe1 for at least 10 minutes

Phase II:

Test pressure Pe1 = 1,0 + 1,1 a (m column of water) is maintained foe half an hour by adding water to the pipeline (if necessary). Amount of makeup water is measured 3 times, always for 6 minutes, in litres (Q1, Q2, Q3).

Phase III:

Conclusion of the test.

Average value of Q1, Q2 i Q3: Qa = 1/3 x (Q1 + Q2 + Q3) (3) Next, Qa is transformed into Qap, expressed in litres/ m x hour: k1 = 60 / 6 = 10 (1/hour) k2 = 1/L (L = length of section under test) Qap = Qa x k1 x k2 (4) Test result is satisfactory if Qap value remains in the shaded area – see Diagram 10.1.a

Explanation of symbols are used: L = ength of pipeline section under test; a = underground water table measured from pipe axis in the middle of tested section (1/2 L) Di = Pipeline inside diameter Pe1 = test pressure 4 4 | Gravity Systems – Manual

Test pressure may be calculated using the formula: Pe1 = P10 + 1,1 a (m column of water) (2) where: P10 = 1,0 m column of water (= 1,0 x 10-2 kPa)

10. Leak proof tests for gravity pipelines Diagram 10.1.Evaluation of water-pressure test results based on amount of make-up water (gravity pipelines)

2,6

Volume of make-up water per length unit and over specific time [l/m h]

2,4 2,2 2,0 1,8 1,6 1,4 1,2 1,0 0,8 0,6 0,4

values accepted

0,2

for plastic pipes 1600

1400

1200

1000

800

600

400

200

0

0

Inside diameter [mm] 2 10.2. Diagram showing the procedure for pressure testing of gravity pipeline between manholes 1

2

3 3

4

1. Additional water tank 2. Pressure equalizing equipment (when necessary) 3. Pressure gauge 4. Valve 5. Plug support 6. Plug 7. Valve

5

a

4 5

a

6

1/2L

1/2L

6 7

1/2L

1/2L

10.3. Diagram showing the procedure for pressure testing of sewage system inspection chambers 1 2

3

a 4 6

5

Legend: l = height of inspection chamber a = underground water table up 1 to the pipeline axis 2 Di = inspection chamber inside diameter 3 1. Additional water tank 2. Pressure equalizing equipment (when necessary) 3. Pressure gauge 4. Plug a 5. Chain 6. Valve

Test pressure: as indicated in Table 1 or acc. to formula (2) Water-pressure test procedure is identical with that used for pipelines (Phases I to III). Test result is satisfactory if Qap value remains in the shaded area â&#x20AC;&#x201C; see Diagram 10.1.a.

The described method is based on finish SFS 3113:E standard. Nowadays the method described in PN-EN 1610 is more common.

4 6

5

Gravity Systems â&#x20AC;&#x201C; Manual | 4 5

11. Installation of Weho tanks

11.1. Methods for installation of Weho tanks Fig. 11.1.a. Installing a Weho tank in the ground

Fig. 11.1.b. Installation of partially sank Weho tank

5

strefa zasypki NIE ZAGĘSZCZAĆ

4 3

strefa obsypki

2

2 1

1

Weho tanks may be installed as under ground or ground-based tanks.

Soils belonging to group 1-3 may be used for subgrade, backfill and top charge. Soils of the group 4-6 (cohesive and organic soils) are not recommended for backfilling. In case of virgin soil belonging to group 4-6, backfill soil should be replaced with that belonging to group 1-3.

Installation of tanks in soils with low carrying capacity (group 4-6) After the soil has been replaced, new soil should be protected against migration of soil grains between virgin soil and new soil. Soil may be reinforced using geotextile mats for example. If flowing or stagnant underground water is found, underground water table should be lowered for the time of installation using pumping wells or drain pipes (see Section “Pipeline installation in the grounds with low carrying capacity”)

Legend: 1. Subgrade (bottom backfill) 2. Main backfill 3. Upper backfill 4. Top charge 5. Virgin soil

5

Table 11.1.a. Examples of soils used in tank installations

Type of soil

Group

Example of soil Gravel - gap grained, valley and beach gravel Sand - gap grained, dune sands, deposited sands, valley sands Clay sand, sand-clay mix – gap grained, watered sand Inorganic loam, fine sand, stone dust, highly plastic clay

loose

1

loose

2

loose

3

cohesive

4

organic

5

Multi-fractional loose soil with humus

organic

6

Peat and other highly organic soils

Examples of reinforcement solutions for low carrying capacity soils Fig. 11.1.c. Reduction of uneven ground settlement

Fig. 11.1.d. Protection constituting complete subgrade, shuttering and soil reinforcement

LEGEND: 1. Geotextile, 2. Backfill zone, 3. Top charge zone

4 6 | Gravity Systems – Manual

Fig. 11.1.e. Protection against migration of fine fractions of the soil

11. Installation of Weho tanks 11.2. Soil compaction Foundation soil should be compacted in layers of 15-20 cm until class W (high density) is reached and depending on type of the backfill material (see Table). Soil density should be in the range of 93 to 100% SPD (Standard Proctor Density).

11.3. Tank foundation depth

Class of density

3 SPD [%]

2 SPD [%]

1 SPD [%]

W (Wysoka)

93 ÷ 96

96 ÷ 100

98 ÷ 100

Fig. 11 3.a. Dry soil (no underground water)

If no underground water is present (dry soil) there is no specific limitation on tank foundation depth (ground cover up to 6 m thick is possible). In places where underground water table is more than 2 m above the tank top, depth and method for tank foundation should be agreed with the design engineer.

Fig. 11.3.b. Watered ground

11.4. Underground water water appears at a level above ¾ of tank height, additional load should be applied. Examples of additional loads are given below. Detailed projects for additional tank loading should be consulted with the design engineer.

For the time of installation, underground water should be pumped out so the installation could be done in dry conditions. For stability, the tank should be progressively filled with water in order to revent it from lifting during soil compaction operation. In addition, some cement may be admixed to stabilize soil around the tank. If underground Fig. 11.4.a. Longitudinal section of an anchored Weho tank

zwg

~3m

zwg

~3m

~3m

~3m

3

1

Fig. 11.4.b. Tank anchorage with the use of reinforced concrete slabs

2

LEGEND: 1. Reinforced concrete relief slab 2. Polyethylene or steel belts 3. Rubber separator

Fig. 11.4.c. Additional loading of two parallel tanks

b – this value depends on the anchor width and the soil compaction conditions.

11.5 Protection of the tank against road traffic When the tank is installed under local traffic lane (squares, storage yards, crossings) it should be relieved. A need for relieving slab and its size should be discussed with the design engineer. Fig. 11.5.a. shows an example of load relieving with the use of reinforced concrete slab.

Fig. 11.5.a. A tank protected by the relieving slab

Gravity Systems – Manual | 4 7

12. Installation of Weho manholes 12.1. Types of Weho manholes 2. Inspection manholes dns 1000, 1200, 1400 *)

dc

dc

dc

350

350

ø 315 dns

dns H

H

H

H

dns

dn

Hp=1400

ht

dns

dns

H

dns

dc

dc

350

h1

3. I nspection chambers and manholes without heavy bottom dns 600, 800, 1000, 1200, 1400 *)

350

1. I nspection chambers dns 400, 500, 600

h2

dn0

h2=800

L

*) Example of dns diametions 5. Example of manhole

dc

dc

350

ht

dc ø 315

350

350

4. I nspection chambers and manholes with heavy bottom dc 1400 *) dns 600, 800, 1000, 1200,

dn0

H

H

H

H

dns dns

dns

dns

zwg

3

h2

3

without heavy bottom (dry soil)

heavy bottom (wet soil)

2 dc 350

dns

1 3

H

H

dns

H

H

2

Fig. 12.1.a. Installation in dry soil

350

350

350

Soilsdc belonging to group 1-3 may be used for subgrade, dc dc backfill and top charge. Soils of the group 4-6 (cohesive and organic soils) are not1recommended. In tank backfill zone soil dns be replaced with that should dnsbelonging to group 1-3.

2

zwg

h2

h2

zwg

1

zwg h2

Fig. 12.1.b. Installation in watered soil - Uponor zwg Infra manhole buoyant force may be calculated with the use of Uponor Infra computer program.

zwg

zwg

zwg

3 zwg

2 1

Depending on the underground water level, manhole may be provided with heavy bottom. Standard height of heavy bottom chamber h2=30cm.

Eccentric or T-connection manholes do not need anchoring with special heavy slabs. Buoyancy is compensated by collecting pipe (see paragraph 12.5).

4 8 | Gravity Systems – Manual

h2

h2

Manhole with heavy bottom filled with lean concrete

T -connection or eccentric manhole with no need for heavy bottom

h2

12. Installation of Weho manholes 12.2. Installation in low carrying capacity grounds paragraph 8.12).

Installation conditions will be defined by the design engineer.

In difficult conditions the so called slab foundation may be used for installation of the manhole. Size and thickness of the slab depend on local conditions.

Installation in low carrying capacity grounds (group 4-6) After replacement of soil, new soil should be protected against migration of grains between virgin soil and the new soil. This may be achieved by the use of geotextile mats.

If flowing or stagnant underground water is found, underground water table should be lowered for the time of installation using pumping wells or drain pipes (see Examples of solutions for low carrying capacity soils: Fig. 12.2.a. Reduction of uneven manhole foundation ground settlement

Fig. 12.2.b. Protection constituting complete subgrade, shuttering and soil reinforcement

Fig. 12.2.c. Manhole installed on foundation slab

350

dc

12.3. Types of soil. Compaction densities dns

Group Example of soil (see Table 8.1.a. for details)

Compaction in SPD%

H

Type of soil loose

1

Gravel - 3gap grained, 3 valley and3 beach gravel3

loose

2

Sand - gap grained, dune sands, deposited sands, valley sands

loose

3

2 sand-clay 2 2 mix – gap2grained, watered Clay sand, sand2

cohesive

4

Inorganic loam, fine sand, stone dust, highly plastic clay

organic

5

Multi-fractional loose soil with humus

organic

6

Peat and other highly organic soils

h2

3

1

1

1

1

1

3

3

3

2

2

2

1

1

1

98 ÷ 1003 96 ÷ 100 93 ÷ 962 -----

1

---

12.4. Anchoting of manhole in wet soil

1

1

zwg

zwg

Vb

- concrete inlet

h2

Depending on the underground water level, manhole may be provided with heavy bottom. Standard height of heavy bottom chamber h2=30cm. Heavy bottom chamber should be filled with lean concrete. For this reason, lower part of the bottom is provided with two opposite filler pipes for pouring the concrete in. After the concrete is pored in, the fillers should be closed using a PE plug.

Table 12.14.a. Approximate concrete volums to fill havy bottom chamber

dn [mm] dns [mm]

200

400

600

800

Vb [m3] 600

0,1

0,1

800

0,2

0,2

1000

0,3

0,4

0,4

1200

0,5

0,6

0,7

1400

0,7

0,9

0,9

1,0

Gravity Systems – Manual | 4 9

12. Installation of Weho manholes 12.5 Concrete slab installation Reinforced concrete relieving slab distributes road surface loads to the manhole surroundings. It prevents the slab from resting directly against upper edge of the manhole structure.

In service the manhole is not allowed to be exposed to traffic generated loads.

dns/DN

dp1

dp2

dp3

a

b

mm 400 telescopic 400 600 800 1000 1200 1400

mm

mm

mm

mm

mm

755

350

-

150

-

1000 1300 1530 1960 2180 2400

600 600 600 600 600 600

700 930 1160 1380 1600

200 200 200 200 200 200

200 200 200 200 200

Fig. 12.5.a.Uponor Infra manhole diagram for buoyancy calculations

NOTE: relieving slab must not rest on upper edge of the vertical part of manhole

LEGEND: 1. Cast iron top (frame and cover) 2. Reinforced concrete slab 3. Sealing 4. Telescope adaptor

12.6. Checking hydrostatic stability of sewage manholes In order to check hydrostatic stability of a sewage manhole we should compare the design value of hydrostatic lift exerted on the manhole with the sum of values of the bearing forces (tare weight and friction of the soil against the external lateral surface of the manhole). The calculation diagram is shown in Fig. 12.6.a.

Checking of hydrostatic stability refers to such design cases, where the ratio between the nominal diameter of the collector and diameter of manhole chamber does not exceed 0.7 and the nominal diameter of manhole is at least 800 mm. In other cases, especially when the collector diameter is larger than diameter of manhole chamber, the calculation of additional load can be neglected. If the condition for manhole hydrostatic stability is not met, the manhole must be equipped with a loading chamber filled with concrete, placed in the bottom part of the manhole.

Calculation of forces exerted on the manhole: The value of hydrostatic lift: The value of friction force of the soil against the lateral surface of a manhole in homogenous backfill:

Calculation of the value of friction force of the soil against the lateral surface of a manhole in complex ground and water conditions is shown below. In accordance with the requirements of the limit state method, for the first limit state (load capacity), the value of unbalance forces should be multiplied by an appropriate increasing coefficient while bearing forces – by a decreasing coefficient.

Adopting the most economical values of correcting factors (provided they are admissible by the standard) (1,1 i 0,9), the necessary 5 0 | Gravity Systems – Manual

anchoring force is as follows: where: Gw – tare weight of manhole. If the calculated value of anchoring force is greater than zero, bearing force should be increased by means of a loading chamber filled with concrete whose depth can be calculated as follows:

zwg DN

H - depth of channel bed [m] H h - ground water level above the channel bed [m] h2 - height of loading chamber [m] concrete bottom Dz - outer diameter of the chamber chamber [m] Dw - inner diameter of the chamber [m] γw - volume weight of water [kN/m3] γ'b - effective volume weight of concrete (γ'b = γb – γw ) [kN/m3] γ - volume weight of the ground [kN/m3] Φ - angle of internal friction of the soil [rad]

Do wet soil

h

h2(=x)

13. Installation of Weholite culverts 13.1. Installation of PE pipes inside jacket pipes.

Due to their strength, PE pipes do not require protection with the use of jacket pipes.

Jacket pipes are used if required by specific regulations, e.g. in water channels under railway tracks where free access to the pipe, without disturbing soil, is recommended.

Distance rings may be used to support PE pipes inside jacket pipes or they may be laid unbounded.

Examples of culverts using Weholite pipes. Weholite pipe culverts do not require jacket pipes.

Weholite culvert under a railway track

Weholite culvert before backfilling

Installation of Weholite culvert 19.5 m long

Weholite culvert under a road

Fig. 13.1.a. Typical Weholite culvert under a road

Fig. 13.1.b. PE pipe inside jacket pipe with distance rings •• •• •• ••• • • • • EMBANKMENT/SOIL

jacket pipe

Weholite culvert • •• ••••• • •• • •••• • •• • •

LEGEND: 1. Subgrade 2. Weholite pipe 3. Backfilling material 4. Roadway

distance rings

• • • • • •• • • • •

Gravity Systems – Manual | 5 1

14. Installation of Weholite Marine system 14.1. General Submerged pipelines can be laid without interference with existing infrastructure, going the shortest way and without need for expensive engineering structures (trestle bridges, flyovers, etc).

Submerged pipelines are laid down, if: 1. a pipeline is to be carried across river below the surface of water (siphon systems) 2. if purified waste water dump into the sea is required – “Marine outfalls” PE pipelines offer perfect behaviour both during underwater installation and in operation. When installation procedure are planned, the design engineer should give careful consideration to the following: - hydraulic calculations, flow rates, tank specifications, etc.

- topographic maps of sea shore line and sea bed - data on winds and wave motions in particular sea area - data on sea currents, - environmental data, such as:

• water temperature outside and inside the pipeline, • properties of transported waste water, • soil conditions, • sea water characteristic.

The above data form minimum necessary information and concern two basic issues to deal with: - transport of drinking water - transport of waste water with the use of open or closed transport systems.

Uponor Infra continuously collects its data acquisition system being a standard in acquiring information necessary in the engineering design and construction of submerged pipelines.

14.2. Gravity pipelines - underwater siphons In gravity pipelines, flow is caused by the difference of waste water levels between two tanks. If level difference is not sufficient to overcome the pipe resistance, use of pumping plant is necessary. With low operating pressures (up to 1 bar), Weholite systems may be considered. If the pressure difference is bigger, WehoPipe pipelines should be used.

Pumping plant will generate pressure needed to overcome head difference between the pumps and the storage reservoir as well as pipeline resistance.

If water level in the receiving tank is not precisely determined, various hydraulic solutions are possible with fixed rate of flow Q and variable values of: - level at the beginning and the end of the system - pipeline diameter - pressure in the pipeline Energy consumption, particularly if ∆H is to be overcome by pumps, has to be considered if optimum solution is needed.

Typical layout of submerged gravity pipeline laid under river surface is shown in Fig. 14.2.a

Fig. 14.2.a. Sectional view of submerged pipeline laid on the river bottom (siphon system)

flowing water

stagnant water

forcing pressure

hyd draulilic gra rad die ien ntt Pumping station

Pw

Q m3/sec L

5 2 | Gravity Systems – Manual

reservoir

14. Installation of Weholite Marine system 14.3. Sea outfalls thermoplastics pipes have found extensive application in construction of the outfalls.

Marine outfalls are designed to dump sewage purified in waste-water treatment plant into sea. Marine outfalls are erected world wide in the majority of seaside cities and conurbations. This solution makes it possible to keep the beaches clean and to prevent the inshore water from secondary contamination.

Generally, length of a marine outfall is from 2 to 3 km.

Underwater outfalls present a unique challenge to designers. Engineering design of such structures requires comprehensive approach and special knowledge of not only structural and hydraulic analysis but also environmental impacts.

Due to excellent properties, such as: - no corrosion; - excellent hydraulic characteristics; - easy installation; - and buoyancy;

flowing water

stagnant water

forcing pressure

hyd draulilic gra rad die ien ntt Pumping station

reservoir

Pw

Q m3/sec L

Fig. 14.3.a. Sectional view of the outfall pipeline H1 hydrau

lic grad

Hp=ΔH

ient

Pw Pumping station MSWL

H2

Outfall Q m 3/

sec

L0

Diffuser section

Ld

Gravity Systems – Manual | 5 3

14. Installation of Weholite Marine system 1

2

14.4. Diffuser systems Diffuser plant may have different arrangement. With regard to sea currents, depth, and microbiology of the water, diffusers have to guarantee uniform distribution of sewage over the water region.

Typical solutions are shown below.

Fig. 14.4.a Examples of diffuser plant solutions

1

1

2

2

1. T-pipe 2. Diffuser plant branch

Length of diffuser plant

Length of diffuser plant

14.5. Method for submerging pipeline – installation at the bottom Typical sectional view of thermoplastics pipeline during submerging operation is shown in Fig. 14.5.a.

Here, the most important parameters are: βo Pi F D PN d T

= proportional conduit load in percent; = air pressure inside conduit; = force necessary to transport the pipeline; = pipeline diameter; = pipeline category (in respect of pressure); = depth of submergence; = temperature

Parameters needed in calculations: β = pipeline inclination during submerging operation; R1 = radius of pipeline curvature near water surface during submerging operation; R2 = radius of pipeline curvature near bottom during submerging operation.

Fig. 14.5.a. Diagram of pipeline submerging

5 4 | Gravity Systems – Manual

In shallow waters, i.e. when depth d < app. 15 x Do, the pulling force F may approach zero.

If d > 15 x Do (deep water), the pulling force must satisfy a condition: F × d2 > Eo × la

14. Installation of Weholite Marine system 14.6. Typical weights are made of reinforced concrete Fig. 14.6.a. Shapes of concrete weights

"Y"

"W" "

"X" 4

4

"

"D

"Y"

"D

"X" "S"

"Y" "X" "S" "Y"

2

4

"4"

"3"

"T"

"X"

"W"

"T"

"W"

"X" "S"

"Y"

"T"

4

"Y"

"

"D

5

14.7. Buoyancy of Weholite pipes in water Table 14.7.a. Buoyancy of Weholite pipes in water depending on degree of their filling with water

dn=di

de

mm

mm

300 350 400 450 500 600 700 800 900 1000 1050 1200 1400 1500 1600 1800 2000

339 401 451 508 562 677 790 903 1016 1128 1179 1354 1588 1694 1830 2056 2282

Maximum buoyancy kp/m

kp/m

kp/m

90 126 160 203 247 354 492 638 811 997 1092 1435 1966 2224 2553 3199 3953 empty pipe, empty walls

20 30 34 44 51 71 107 136 175 211 226 304 427 457 542 654 812 pipe fully filled, empty walls

0 0 1 1 1 1 2 2 3 3 4 4 5 7 8 10 12 pipe and walls filled with water

"X"

Specific gravity of concrete is 2400 kg/m3. Load applied to Weholite pipeline should be up to 30% buoyancy maximum when submerging.

After placing the pipeline on sea bed, additional weight may be mounted. These weights are made of reinforced concrete.

Fig. 14.7.a Profile of flexible rubber belt

Flexible belt Flexible belts are placed between pipeline and concrete weights. They prevent unwanted displacement of weights and even up irregularities of the weight surface.

6,5 6,5

6,2 6,2

5555

6,5 6,5

1010

6,2 6,2

3030

1010

Gravity Systems â&#x20AC;&#x201C; Manual | 5 5

15. Renovation of gravity pipelines 15.1. General Uponor Infra pipes may be used in repairs of existing gravity pipelines with diameters ranging from 90 to 3000 mm. In general, REINFORCED CONCRETE -, STEEL- or CAST IRON pipelines are subject to renovation. Renovation is aimed at restoring original technical specification (structural reinforcement, flow capacity) deteriorated during years of operation due to corrosion, structural damages or unsealed connections.

Due to leakage to the ground damaged buried pipelines may cause serious risk to road surfaces and even to building structures leading to their caving in or collapse. Pipeline relining is one of the most efficient methods for restoring their full functionality. New pipe fitted inside the old channel not only makes it tight but also reinforces its structure and inhibits further deterioration.

Relining consists in inserting joined PE pipes in repaired pipeline in order to form new and completely tight conduit.

purposes are supposed to satisfy at all times their specific criteria (of a physical, chemical, biological or biochemical nature). This depends on many factors, such as correct engineering design, execution, materials used and service life. Good management is also needed to keep pipelines operational. Besides inspections and routine service of the equipment, improvements may also become necessary.

Pipelines undergo modernization when their performance characteristic requires improvement. This may include repair, renovation or replacement. Insertion of new plastic pipeline into the old conduit has become the basic technique.

Problem of pipeline improvements has acquired significance for the past 10 years. Existing pipeline systems serving various 15.2. Application of Uponor Infra pipes in repairs of gravity pipelines Uponor Infra is the manufacturer of materials used for various repairs of pipeline systems. These are: Application

PE System

Gravity pipelines, sewage systems (sewers, storm-water drains) Sections from 70 m up to several hundred meters long Inside diameter exceeding 350 mm

Weholite From 300 mm to 3000mm

Gravity pipelines, sewage systems (sewers, storm-water drains) Minimum pipe internal necking Sections from 70 m up to several hundred me

WehoPipe SDR26, SDR21 From 90 to 1800mm

Repairs using “manhole to manhole” method Sections app. 70 m long Congested streets

VipLiner Modules from 90 to 630 mm, 50 cm long.

Other length on request

Drains (manholes)

Weho manholes

Diameter details can be found in Product Catalogue.

5 6 | Gravity Systems – Manual

15. Renovation of gravity pipelines 15.3. Preliminary work

• Engineering design-based analysis of the route and profile

of the existing pipeline together with an on-site visit • Determination of location and number of excavations.

Size of excavations (wide or narrow trench) will depend on the depth of pipeline and method for its reinforcement • Evaluation of technical condition of pipeline section to be repaired (possible lateral dislocations, slumps, cross section deformations, etc.)

• Rectification of collapsed structural elements, removal of corrosive overhangs, weld overlaps, etc.

• Selection of PE pipe of suitable technical specification – outside diameter, flow capacity 15.4. Scope of work

• Spot excavations necessary to introduce a CCTV camera

together with removal of the existing pipe sections • Examination of pipeline route with the use of CCTV camera • Execution of installation excavations • Draining the excavations (if necessary) • Steel wire brushing (in case insertion of the PE pipes might be hampered by extensive local deposits on pipe walls) • Pipeline calibration • Fabrication of pipeline head for drawing the PE pipe in • Pulling through the PE head with PE pipeline section several meters long

• Calibration of the old conduit to make sure that outside

diameter of the new PE pipe is correct

• Division of repair work into stages: the pipeline should be divided into straight sections. Basically, new pipes are inserted or new chambers installed in spots of change in pipeline direction • Selection of spots for pipe insertions depends on local conditions, access roads, etc.

• Joining PE pipes into sections corresponding to the length

of renovated pipeline between subsequent installation excavations • Drawing pipes into the pipeline • Installation of fittings (manholes and elbows) in excavations and joining the pipe sections already drawn in • Backfilling • Surface reconstruction

Note: It is recommended to fill the space between pipes with a material (e.g. cement-ash mix) composed individually depending on given design assumptions.

15.5. Standard equipment needed for relining

• Depending on soil conditions – a slab to stand the welding machine • Drag shovel – bucket 1.5 m3.

• Generating set

• Crane • Power winch • Air compressor • Air hammers

15.6. Pipe connections PE pipes may be joined in various ways depending on the method used for repair and type of a system::

System Weholite - from 300 to 3000 mm WehoPipe - from 90 to 1800 mm VipLiner - modules – from 90 to 630 mm

Type of joint Extrusion welding (700 – 3000 m) Screw joint + welding (350 – 1200 mm) Snap-Joint (600 - 1200 mm) Butt welding Snap-Joint

15.7. PE pipe pull in heads The head is used to connect the pipeline with power winch with the use of rope. Its construction has to withstand stress and friction force generated when one pipe is pulled in another pipe. The head protects the pipeline face against damage that may be caused by the old conduit. The can be reused for installing the next section.

Gravity Systems – Manual | 5 7

15. Renovation of gravity pipelines 15.8. Renovation methods Joining the pipes outside excavation (assembly chamber) Criteria for selection of joining of pipes outside excavation: • Long sewer sections for repair – long distances between manholes or no manholes • Large space available (strip of land long enough) for joining the pipes outside excavation

• Complete earthwork draining or shut down of pipeline not possible

• Pace of work – pipe joining independent of other preliminary and repair work.

Relining practice consists in drawing in a PE pipeline with inside diameter smaller than actual inside diameter of the old pipeline, taking internal necks, deformations and dislocations into consideration.

System

Recommended length of inserted sections

Weholite

Renovation in two directions may be done starting from one excavation. Normally, a pipeline 400 m long drawn in.

WehoPipe

Depending on the condition of old pipeline and characteristic of inserted pipe (DN, SDR) it is even possible to draw in sections longer than 1000 m

When renovation is completed, it is recommended to fill free space between pipes with injected mix for better stability.

Moreover, penetration of underground water is thus prevented as well as possible free spaces around pipeline are eliminated.

In general, assembly chambers are located in points where the route changes direction. Next, starting excavations are made there and their length depends on the pipeline installation depth and the permissible pipe bend radius. One starting excavation may be used to insert pipeline in two directions.

When long pipeline sections welded on the ground surface are drawn in, it is necessary that size of excavation or assembly chamber is adjusted to permissible pipe bending radius.

Fig. 15.8.a. Sectional view of the starting excavation for inserting PE pipe segment into old conduit

R R

H

H 2

2H

PE pipe

IG2 IG1 2IG2

R – Minimum PE pipe bending radius: For Weholite selected individually

R= 30 DN

Short-term (for the time of installation)

R= 50 DN

DN Long-term (for the time longer than 12 hrs)

5 8 | Gravity Systems – Manual

da Da

I'

15. Renovation of gravity pipelines Pulling force for PE pipelines Maximum pulling force that may be safely applied to a PE pipeline is calculated basing on the design stress σd (see paragraph Nominal Pressure).

For C= 1,25 ( wg ISO 12 126)

MRS 10,0 [MPa]

MRS 8,0 [MPa]

σ

8,0

6,3

d

o

(the above values refer to temperature of 20 C)

Permissible pulling forceaw in sections longer than 1000 m

When calculating pipe pulling force pipe weight and coefficient of friction between pipe and subgrade should be taken into account

Fmax =

F = q L (µ cos

σ

where: A – pipe wall cross section area Note: Weholite pipes have structural walls, see paragraph 3.2

A d

ϕ +/- sin ϕ)

where: q – pipe unit weight [N/m] L – length of inserted segment µ – coefficient of friction (max. 0.8) ϕ – angle of pipeline inclination

Dimensions of a starting excavation Dimensions of the starting excavation depend on depth of pipeline installation and its bend radius:

LG1 =

H (4 R – H)

If the inserted pipe may be lifted to the height H above the ground, length of the starting excavation may be reduced by:

LG2 =

H (2 R – H)

Length of the open trench:

L’ =

Dn(2R-Dn)

Angle of inclination of the starting excavation may be calculated from the formula:

tg

ϕ = (H – Dn)/( L

– L’) G

where: H – depth of pipeline installation R – bend radius where: H – depth of pipeline installation R – bend radius where: Dn – nominal pipe diameter R – bend radius where: H – depth of pipeline installation R – bend radius

Joining pipes inside excavation (in the assembly chamber) After inspection, cleaning and calibration of the old conduit it is necessary to determine locations where new pipeline would be inserted. If starting excavations of enough length corresponding to the depth of pipeline installation and permissible bend radius cannot be made, short-distance relining should be decided using the existing manholes or inspection chambers where short Weholite, WehoPipe or VipLiner modules are inserted.

In this method short modules are inserted after having been connected inside the starting chamber. Joining method depends on the system selected – Weholite, WehoPipe or VipLiner. Length of inserted modules depends on dimensions of the starting chamber and may be selected freely.

When all the modules have been inserted, a mix is injected in between the pipes to fill all free spaces and stabilize the whole system.

If pipes are joined inside chamber, it is necessary to take care about: • correct protection of excavation walls • suitable base for welding machine (use of foundation slab)

• minimum operational dimensions of the chamber (dimensions of

welded pipe sections - standard 12.5 m,and the dimensions of the machine and passageways for welders) roofing sealers against harsh weather conditions during welding • time and stopping time • permanent drainage of trench

Gravity Systems – Manual | 5 9

15. Renovation of gravity pipelines Fig. 15.8.b. Installation of pipes in the excavation or in the assembly chamber

L

L

Such parameters as the pulling force, type of equipment are the same as when joining the pipes outside excavation.

15.9. Repair using â&#x20AC;&#x153;From one manhole to the next oneâ&#x20AC;? method - VipLiner System Here, short modules connected with the use of special snap joints with a seal are inserted in the repaired conduit from the starting chamber.

Due to special construction of the joint high mechanical strength and 100% tightness are achieved.

VipLiner method does not require any excavations. Immediate positive effect is achieved. The work may be completed without any disturbance to the road traffic. Also sewage system may be operated when the work is in progress.

Short VipLiner modules are available from 90 to 630 mm.

Useful length of modules is 0.5 m while their design length is

6 0 | Gravity Systems â&#x20AC;&#x201C; Manual

0.55 m. This is determined by the manhole chamber diameter.

Standard module length makes it possible to insert them even from manholes with diameter of 800 mm. Longer modules are available when larger manhole diameters are used.

Use of hydraulic equipment for pushing the modules one after another makes work easier when longer sections are subjected to renovation.

After all the modules have been inserted, special mix is injected between old pipe and the VipLiner in order to fill all free spaces and to stabilize the whole system.

15. Renovation of gravity pipelines VipLiner system is characterized by: • capability to carry work while the conduit is in operation • quick and easy installation • Very low cost of renovation

Effects of repair when using the VipLiner system

• Sealing the old conduit • Structural reinforcing of conduit • Reduced resistance of flow • Extended service life of the repaired section

15.10. Renovation of manholes AWhen evaluating technical condition of a collector qualified for renovation, existing manholes should be also taken into consideration. Poor condition of the manholes may produce the same risk as that caused by the leaking pipelines. Even if no infiltration of the underground water was found in the manholes prior to renovation, underground water table may be raised after the conduit is made tight - resulting in leaking manholes.

Consequently, in areas with high underground water table renovation of manholes should be also considered.

Chamber renovation using Weho Ø 1000

Renovation of manholes consists in: • installation of new Weho manhole inside the old concrete sump • complete replacement of old sumps with new Weho manholes

PE manholes used for renovation Cast iron cover Telescopic PE pipe

Manufactured range of PE pipes allows renovation of existing conduits and manholes of various diameters and dimensions.

Connection of vertical part with newly inserted PE pipeline is made by extrusion welding.

Old concrete inspection chamber Gravel

Concrete filling

Home connection

PE pipe

Gravity Systems – Manual | 6 1

16. Transport and storage of PE and PP pipes 16.1. Transport

Loading and unloading of pipes on pallets should be effected with the use of fork lifts with smooth forks. Pallets may not be damaged and should be strong enough not to present risk to personnel.

Pipes loaded individually must be suspended on soft slings such as polyester belts of suitable strength. Use of rods, hooks or metal chains may lead to damages when pipes are incorrectly handled.

Trucks with flat loading platform or special vehicles for transport of pipes should be used. No nails or other elements may protrude from the platform. Side boards should be flat and without sharp edges. Pipes with biggest diameters should be loaded directly on the platform. Individually loaded pipes should be separated with wooden slats so the slings may be threaded between pipe layers for unloading. In case of socket pipes, sockets should not touch one another. Pipes should be bound together tightly so they would not move during transport. During transport pipes should not hang down more than five times nominal diameter and not more than 2 metres (smaller value applies).

During unloading pipes must not be dropped in the uncontrolled manner. Otherwise, mechanical damage may occur. Pipes should be transported to a storage yard.

Strength of plastic pipes decreases when temperature drops.

Therefore, particular caution is needed when unloading plastic pipes in low ambient temperatures.

For manual unloading polyester slings should be used.

Unloaded pipes must not produce any hazard to personnel.

Lifting equipment and proper slings should be used when unloading heavy pipes. Nobody is allowed to stay under the suspended load or within reach of the crane.

6 2 | Gravity Systems â&#x20AC;&#x201C; Manual 1m

16. Transport and storage of PE and PP pipes 16.2. Storage

Pipe storage yard should be accessible to personnel, e.g. quality control staff. Easy access should be also provided for further transport. Pipes must not be stored near open fire, sources of heat or dangerous substances: fuel, solvents, oils, paints, etc.

Wooden separators should be used during storage of pipes in the same way as in transport. Wooden slats should be flat and wide to avoid deformation of pipes. Biggest diameter pipes should be placed at the bottom. In case of socket pipes deformation of sockets should be avoided (alternating arrangement).

Black PE pipes are resistant to UV rays. They can be stored on site without a roof. h

Max 2,5 m

Pipes should not rest directly on the floor. It is necessary to use supports - similar to wooden slats placed between pipes.

Distance between supports should not exceed 2.5 m. The floor should be flat and without sharp elements. Stacking height should not exceed 3-4 m.

h

Max 2,5 m

Table 16.1.a. Pipe stacking height

Rodzaj Systemu

Maximum approximate stacking height h [m]

Weholite WehoDuo WehoTripla

3,0 - 4,0 m Two pallets Two pallets

Gravity Systems â&#x20AC;&#x201C; Manual | 6 3

17. PE and PP chemical resistance Symbols:

PE-HD PE-MD PP s.s.

- high density polyethylene - medium density polyethylene - polypropylene - saturated solution

1 – resistant 2 – partly resistant 3 – non-resistant

Data shown in the table have been obtained from ISO TR 10358, ISO TR 7472 and 7474 documentations

Compound

Chemical formula

Content (%)

Acetone

CH3-CO-CH3

100

Benzaldehyde

C6H5CHO

100

Acetaldehyde

CH3CHO

100

Allyl alcohol

CH2=CH-CH2OH

96

Amyl alcohol

C5H110H

100

CHC CH2OH

100

Al2(SO4)3K2SO4 -4H2O

<10

Ammonia (solution)

NH3

<10

Ammonia (gas)

NH3

100

Ammonia (liquid)

NH3

100

C6H5-NH2

100

Ammonium nitrate

NH4NO3

s.s.

Magnesium nitrate

Mg(NO3)2

Copper nitrate

Cu(NO3)2

Nickel nitrate

Ni(NO3)2

Furfuryl alcohol Alum

Aniline

Potassium nitrate

KNO3

Mercury nitrate

Hg(NO3)2

Sodium nitrate

NaNO3

Silver nitrate

AgNO3

Calcium nitrate

Ca(NO3)2

Iron nitrate

Fe(NO3)3

Sodium nitrite Benzene

>10

>10

NaNO2 C6H6

100

Petrol Sodium benzoate

C6H5COONa

Acetic anhydride

CH3CO-O-COCH3

Borax

100

Na2B4O7

Bromine (gas)

Br2

100

Bromine (liquid)

Br2

100

Potassium bromide

KBr

Sodium bromide

6 4 | Gravity Systems – Manual

NaBr

Temp. (°C) 20 60 20 60 20 60 20 60 20 60 20 60 20 60 20 60 20 60 20 60 20 60 20 60 20 60 20 60 20 60 20 60 20 60 20 60 20 60 20 60 20 60 20 60 20 60 20 60 20 60 20 60 20 60 20 60 20 60 20 60 20 60

PE 2 2 2 3 1 2 1 1 1 2 1 2 1 1 1 1 1 1 1 1 1 2 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 2 3 1 2 1 1 1 2 1 1 3 3 3 3 1 1 1 1

PP 1 1

1 1 1 1 1

1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1

2 3 3 3 1 1 1 1 3 3 3 3 1 1

17. PE and PP chemical resistance Compound

Chemical formula

Content (%)

Potassium trioxobromate

KBrO3

Butane

C4H10

100

C4H9OH

100

Butyl alcohol Chlorine (solution)

Cl2

Chlorine (gas)

Cl2

Potassium chlorate

KClO3

Calcium chlorate

Ca(ClO3)10

Sodium chlorate

NaClO3

Ammonium chloride

NH4Cl

Boron chloride

BaCl2

Zinc chloride

ZnCl2

Tin chloride

SnCl2

Aluminium chloride

AlCl3

Magnesium chloride

MgCl2

Copper chloride

CuCl2

Nickel chloride

NiCl2

Mercury chloride

HgCl2

Potassium chloride

100

s.s.

s.s.

KCl

Sodium chloride

NaCl

Thionyl chloride

SOCl2

Calcium chloride

CaCl2

Iron chloride

FeCl3

Trichloromethane

ClcCH

100

Chloromethane

CH3Cl

100

Potassium chromate

K2CrO4

Tetraoxochromc acid cleaning mixture Potassium cyanide

100

CrO3H2O

>10

KCN

>10

Mercury cyanide

Hg(CN)2

Sodium cyanide

NaCN

Silver cyanide

AgCN

Hydrogen cyanide

HCN

10

C6H11OH

100

Cyclohexanone

C6H10O

100

Decalin (decahydronaphtalene)

C10H18

100

(C6H10O5)n

>10

Cyclohexanol

Dextrin

Temp. (°C) 20 60 20 60 20 60 20 60 20 60 20 60 20 60 20 60 20 60 20 60 20 60 20 60 20 60 20 60 20 60 20 60 20 60 20 60 20 60 20 60 20 60 20 60 20 60 20 60 20 60 20 60 20 60 20 60 20 60 20 60 20

PE 1 1 2 2 1 1 2 3 2 3 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 3 3 1 1 1 1 3 3 2

PP 1 1 1

1 1 1 2 1 1 1 1 1 1 1 1 1

1 1 1 1 1

20 60 20 60 20 60 20 60

1 2 2 2 1 2 1 1

1 3 2 3 3 3 1 1

1 2 1 2 3 3 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1

2 3

1 1

Gravity Systems – Manual | 6 5

17. PE and PP chemical resistance Compound

Chemical formula

Yeast

Content (%) >10

Potassium dichromate

K2CrO4

Dioxolane

C4H3O2

100

Carbon disulphide

CS2

100

Chlorine dioxide

ClO2

100

Sulphur dioxide

SO2

100

Ethyl alcohol

C2H5OH

40

Diethyl ether

C2H5-O-C2H5

100

Phenol

C6H5OH

>10

Fluorine

F2

100

Ammonium fluoride

NH4F

>10

Aluminium fluoride

AlF3

s.s.

Potassium fluoride

KF

Sodium fluoride

NaF

Formaldehyde

HCHO

40

Octyl phatalate

C6H4(COOC8H17)2

100

CHOH CH2OH

100

OHCH2CH2OH

100

Glycerol Ethylene glycol Glucose

C6H12O6 CH2OH

Heptane

C7H16

100

Hydroquinone

C6H4(OH)2

Xylene

C6H4(CH3)2

100

COOH(CH2)4COOH

s.s.

Adipic acid Arsenic acid

H3AsO4

Nitric acid

HNO3

25

Nitric acid

HNO3

50

Nitric acid

HNO3

75

Nitric acid

HNO3

100

Benzoic acid Hydrobromic acid Boric acid Chloroacetic acid Citric acid

C6H5COOH HBr

10

H3BO3 ClCH2-COOH

>10

HOO CH2-C(H) (COOH)-CH2COOH

Hydrofluoric acid

HF

4

Hydrofluoric acid

HF

60

6 6 | Gravity Systems – Manual

Temp. (°C) 20 60 20 60 20 60 20 60 20 60 20 60 20 60 20 60 20 60 20 60 20 60 20 60 20 60 20 60 20 60 20 60 20 60 20 60 20 60 20 60 20 60 20

PE 1 1 1 1 1 1 2 3 1 1 1 1 1 2 2 3 2 2 3 3 1 1 1 1 1 1 1 1 1 1 1 2 1 1 1 1 1 1 1 3 1 1 2

20 60 20 60 20 60 20 60 20 60 20 60 20 60 20 60 20 60 20 60 20 60 20 60 20 60

1 1 1 1 1 1 2 3 3 3 3 3 1 1 1 1 1 1 1 1 1 1 1 1 1 2

PP

2 2 1 3 1 1 1 1 1 1 2 1

1

1 1 1 2 2 1 1 1 1 1 3 3 2

1 2 3 3 3 3 3 1 1 2 1 1 1 1 1 2

17. PE and PP chemical resistance Compound Gluconic acid

Chemical formula

Content (%)

OHCH2COOH

>10

Maleic acid

HOOCCH=CHCOOH

Butyric acid

C3H7COOH

100

Lactic acid

CH3CH(OH)COOH

100

Formic acid

HCOOH

50

Formic acid

HCOOH CH CH

98-100

Nicotinic acid

<=10

Acetic acid

CH3COOH

10

Acetic acid

CH3COOH

96

Oleic acid

C8H17CH=CH- (CH2)7COOH

100

H3PO4

50

Orthophosphoric acid Picric acid

(NO2)3C6

Propanoic acid

CH3CH2COOH

50

Propanoic acid

CH3CH2COOH

100

Salicylic acid

C6H4OHCOOH

Trioxosulphuric acid

H2SO3

30

Sulphuric acid

H2SO4

10

Sulphuric acid

H2SO4

50

Sulphuric acid

H2SO4

98

Fuming sulphuric acid

H2SO4

fuming

Hydrochloric acid

HCl

10

Hydrochloric acid

HCl

Concentr.

Oxalic acid

(COOH)2

Toluic acid

C6H3COOH

Tartaric acid

COOH(CHOH)2COOH

using. conc.

Molasses Methyl alcohol Milk

>10

CH3OH

100

(Krowie i owcze)

100

(NH2)2CH

>10

Urine Urea Potassium perchlorate

KClO4

Potassium permanganate

KMnO4

20

Potassium persulphate

K2S2O8

20

Wine vinegar

see vinegar

Amyl acetate

CH3COO(CH2)4CH3

100

Temp. (°C) 20 60 20 60 20

PE 1 1 1 1 1

PP 1

20 60 20 60 20 60 20 60 20 60 20 60 20 60 20 60 20 60 20 60 20 60 20 60 20 60 20 60 20 60 20 60 20 60 20 60 20 60 20 60 20 60 20 60 20 60 20 60 20 60 60

1 1 1 1 1 1 1

1 1 1 1 1 3

1 1 1 2 1 2 1 1 1

1 1 1 2 2 3

1 1 1 2 1 1 1 1 1 1 1 1 1 3 3 3 1 1 1 1 1 1 2

1

1 1 1 1 1 1 1 1 1

1 1

20 60 20 60 20 60 20 60 20 60 20 60

1 1 1 1 1 1 1 1 1 1 2 3

1

1 1

1

1

1 1 1 1 1 2 3 1 1 1 2 1 2

1 2 1 1

1 1 1 1 1 1 2

Gravity Systems – Manual | 6 7

17. PE and PP chemical resistance Compound

Chemical formula

Content (%)

Ethyl acetate

CH3COOC2H5

100

Silver acetate

CH3COOAg

Oil and grease Mineral oils Sodium orthophosphate Potassium orthophospahate Ozone

Na3PO4 K3PO4 O3

100

Perhydrol

H2O2

30

Perhydrol

H2O2

90

C5H5N

100

KClO

>10

Sodium oxochlorate

NaClO

5

Calcium oxochlorate

Ca(ClO)2 4H2O

<10

Hg

100

(NH4)2SO4

s.s.

Pyridine Beer Potassium oxochlorate

Mercury Ammonium sulphate Barium sulphate

BaSO4

Zinc sulphate

ZnSO4

Aluminium sulphate

Al2SO4

Copper sulphate

CuSO4

Nickel sulphate

NiSO4

Potassium sulphate

K2SO4

Sodium sulphate

Na2SO4

Calcium sulphate

CaSO4

Iron sulphate Ammonium sulphide

s.s.

Fe2(SO4)3 (NH4)2S

>10

Barium sulphide

BaS

>10

Potassium sulphide

K2S

>10

Calcium sulphide

CaS

<10

Sodium sulphate

Na2SO3

Hydrogen sulphide (gas) Tannic acid Carbon tetrachloride Oxygen Zinc oxide

6 8 | Gravity Systems – Manual

H2S

100

C14H10O9

>10

CCl4

100

O2

100

ZnO

Temp. (°C) 20 60 20 60 20 60 20 60 20 60 20 60 20 60 20 60 20 60 20 60 20 60 20 60 20 60 20 60 20 60 20 60 20 60 20 60 20 60 20 60 20 60 20 60 20 60 20 60 20 60 20 60 20 60 20 60 20 60 20 60 20 60 20

PE 1 3 1 1 1 2 1 2 1 1 1 1 2 3 1 1 1 3 1 2 1 1 1 2 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 2 2 1 1 1 1 1

PP 2 3 1 1

20 60 20 60 20 60

2 3 1 2 1 1

3 3 1

1 2 2

1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1

1 1

17. PE and PP chemical resistance Compound

Chemical formula

Content (%)

CO

100

C6H5-CH3

100

Antimony trioxide

SbCl3

90

Phosphorus trioxide

PCl3

100

Trichlorethylene

Cl2C=CHCl

100

Triethanolamine

N(CH2CH2OH)3

>10

Sulphur trioxide

SO3

100

Carbon monoxide Toluene

Barium carbonate

BaCO3

Zinc carbonate

ZnCO3

Magnesium carbonate

MgCO3

Potassium carbonate

K2CO3

Sodium carbonate

Na2CO3

Calcium carbonate

CaCO3

Wines and spirits (commercial concentrations) Water Aqua regia (nitrohydrochloric acid) Hydrogen Sodium hydrogen-(ortho) phosphate

H2O HCl + HNO3

3/1

H2

100

Na2HPO4

Potassium hydrogensulphate

KHSO4

Potassium bisulphite

KHSO3

>10

Sodium bisulphite

NaHSO3

>10

Barium hydroxide

Ba(OH)3

Magnesium hydroxide

Mg(OH)2

Potassium hydrogencarbonate

KHCO3

Sodium hydroxide

NaOH

>10

Sodium hydroxide

NaOH

40

Potassium hydroxide

KOH

10

Potassium hydroxide

KOH

>10

Calcium hydroxide

Ca(OH)2

Sodium hydrogencarbonate

NaHCO3 norm. conc.

Photographic developer Potassium ferricyanide

K3Fe(CN)6

Potassium ferrocyanide

K2Fe(CN)6

Sodium ferricyanide

N3Fe(CN)6

Sodium ferrocyanide

N4Fe(CN)6

Temp. (°C) 20 60 20 60 20 60 20 60 20 60 20 60 20 60 20 60 20 60 20 60 20 60 20 60 20 60 20 60 20 60 20 60 20 60 20 60 20 60 20 60 20 60 20 60 20 60 20 60 20 60 20 60 20 60 20 60 20 60 20 60 20 60 20 60 20 60 20 60 20 60

PE 1 1 2 3 1 1 1 2 3 3 1 2 3 3 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 3 3 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 2 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1

PP 2 3

1

1 1 1 1 1 1 1 1 1 1 1 1 1 3 3 1

1 1 1

1 1 1 1 1

1 1 1 1

Gravity Systems – Manual | 6 9

NOTES

7 0 | Gravity Systems â&#x20AC;&#x201C; Manual

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