Pressure Systems Properties, designing, assembling WehoPipe, WehoPipe RC/RC+
Pressure Systems Uponor Infra - manual | 1
Contents
1. General ....................................................................................... 4 2. Properties of PE pipelines ........................................................... 6 3. Design parameters of PE pipes .................................................. 8 4. Hydraulic calculations for pipes with pressure flow ................... 12 5. Installation of pressure pipes in the ground .............................. 27 6. PE pressure pipe connections................................................... 39 7. Leak proof test of pressure pipelines ........................................ 46 8. Relining of pressure pipelines with PE pipes ............................ 47 9. Handling and storage of PE pipes ............................................ 51 10. Chemical resistance tables for PE and PP ............................... 53
Pressure Systems Uponor Infra - manual | 3
1. General 1.1. Current standards, guidelines and recommendations Uponor Infra Sp. z o.o. (formerly KWH Pipe Poland Sp. z o.o.) is certified to ISO 9001 and ISO 14001, in recognition of our efforts to maintain the highest standards in manufacture and sale of our products. Each product is covered by appropriate control plan and quality of the supplied products is based upon the standards valid within all EU countries. Tests are performed on the controlled testing equipment in our in-house laboratory, which allows trusting the results obtained.
PE pipes and fittings made by Uponor Infra, widely used in the building industry, have technical approvals issued by the ITB (Institute of Building Technology) in Warsaw, Poland. Our products designed for potable water are made of raw materials with hygienic certificates issued by Państwowy Zakład Higieny (National Institute of Hygiene) in Warsaw.
Our pressure pipelines have the following approvals for the Polish market:
Product
Application
ITB
PZH CERTIFICATES
GIG
PE WehoPipe pressure pipes and fittings
Water supply & pressure sewer systems
PE WehoPipe RC/RC+ pressure pipes and fittings
Water supply & pressure sewer systems
In the Uponor Infra Sp. z o.o. approval processes, the following international (ISO), European (EN) and national (e.g. PN, SFS) standards were applied. Below, there are some examples of the most important of them presented: Standard
Designation
ISO 4427 1-3
Polyethylene(PE) pipes for water supply- Specifications
ISO 4065
Thermoplastic pipes – Universal wall thickness table
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
PN-EN ISO 3126
Plastics piping systems. Plastics components. Determination of dimensions
PN-EN 12201
Plastics piping systems for water supply, and for drainage and sewerage under pressure. Polyethylene (PE) pipes
PN-EN 805
Water supply - Requirements for external systems and their components
1.2. Properties of PE material Properties
PE100
1
MRS
[MPa]
10
2
Density (r)
[kg/m ]
≥930
3
Melt Flow Rate (PE:190ºC, 5kg)
[g/10 min]
0.2-0.4
4
Tensile strength (to melt flow point)
[N/mm2]
18-29
5
Elongation at break
[%]
≥500
6
PE brittleness temperature
[ºC]
<-70
7
Hardness, Shore D
Shore D
55-60
8
Thermal linear expansion coefficient (a)
[mm/mºC]
0.15-0.20
4 | Pressure Systems Uponor Infra - manual
3
1. General 1.3. WehoPipe pressure system â&#x20AC;&#x201C; Applications
Water supply systems
Pressure sewer systems
Underwater pipelines
Areas of mining damage
Relining
Process and transmission pipelines
Horizontal drilling
Drainage of airports, logistics centres, etc.
Pressure Systems Uponor Infra - manual | 5
2. Properties of PE pipelines 2.1. Advantages of PE PE material advantages have contributed to the widespread use of polyethylene pipes and fittings for the construction of water and sewage infrastructure. The most important of these include: • High abrasion resistance • Corrosion resistance (to chemical compounds) • Very good hydraulic properties • Intoxicity
• 100% tightness of joints • Flexibility • Low weight of pipes • Reliability
High abrasion resistance Abrasion resistance is one of the most distinctive features of PE among all the other materials used in the construction of pipelines. Due to their characteristics, PE pipes are used to transport sludge, sand and other highly abrasive media. For the Darmstadt test method, pipes made of commonly used materials were used, the samples of which were filled with a mixture of sand and water and subjected to a cyclic alternating
tilting. Amount of worn (abraded) material on the pipe walls was measured in regular intervals. The test result showed the very high wear resistance of Polyethylene pipes, for example for 400 000 cycles, only 0.3 mm material loss on the surface of PE pipes was measured, whereas in the case of fibreglass tubes (GRP) the measured loss was 6 - 8 times larger (University of Darmstadt test, Germany).
asbestos pipes
Abrasion [mm]
fibreglass tubes
concrete pipes stoneware pipes PVC pipes PE pipes No. of cycles during the test, N SOURCE: University of Darmstad (DIN 19534)
Corrosion resistance PE pipes are resistant to many chemical compounds, under which conventional pipe materials undergo rapid corrosion and aging, such as most acids (except nitric acid), alkalis, salts and aliphatic solvents (pH 0-14). Polyethylene pipes are poorly resistant to oxidants and aromatic solvents. PE resistance to chemicals is dependent on the temperature, concentration and pressure of the compound. Detailed data on the chemical resistance of PE and other thermoplastic materials can be found in ISO / TR 10358.
6 | Pressure Systems Uponor Infra - manual
2. Properties of PE pipelines Hydraulic properties PE pipes maintain low and constant coefficient of absolute roughness k equal to 0.01 mm. Lack of corrosion and fouling of PE pipes from the inside is one of the most important utility advantages of the PE systems.
Intoxicity In the Weho system, you can make tanks of water intended for human consumption. These tanks are made of PE material with PZH (National Institute of Hygiene) approval.
100% tightness of joints PE pressure pipes can be joined by butt welding using welding machines or other Uponor Infra welders suitable for PE pipes. Butt weld joint is 100% tight and, if properly made, ensures trouble free operation throughout the pipeline lifetime. The welded joint is homogenous with the pipe material.
Flexibility By using natural bending radius, you can install PE pipes in accordance with the change of the route, which often allows avoiding the use of expensive fittings. Flexibility is the feature that distinguishes PE from other traditional materials.
Low weight of pipes Low weight of pipes can reduce costs and shorten the installation time. As a result, PE pipes do not require the use of heavy equipment for stacking and unloading at the construction site. Approximate weight of pipes PE DN1000 - 120 kg/m Betras DN1000 - 700 kg/m Cast iron DN1000 - 300 kg/m Reliability PE failure frequency is much smaller than the same of rigid pipes (e.g. cast iron, steel & GRP). PE pipes are resistant to changing weather conditions. They can be installed and transported both at low (freezing) or very high (tropical) temperatures. For these reasons, inter alia, PE pipes are widely used around the world regardless of the climatic zone.
Pressure Systems Uponor Infra - manual | 7
3. Design parameters of PE pipes 3.1. Resistance to the fluid temperature The following chart illustrates the differences in the operating temperature ranges for pressure and gravity PE pipes.
oC
100 80 Pressure pipes
60 40
Gravity pipes
20 0 -20 -40
PE
When designing a pressure pipe made of polyethylene (PE), you can assume that its service life will be at least 50 years, provided that the pressure will exceed the nominal design pressure of the pipes, and the flowing medium is water having a temperature not exceeding 20°C. Temperature of the flowing fluid,besides the pressure, has a major influence on the service life of thermoplastic pipes (e.g. PE). As the temperature rises above a predetermined value, the life of the pressure pipeline decreases. In order to maintain the stability of the pipeline in line with the objectives, i.e. 50 years of operation, a correction coefficient
The relationship between temperature and the coefficient k is contained in the following table: Temperature [Co]
Correction coefficient k
20
1.0
30
0.87
40
0.74
8 | Pressure Systems Uponor Infra - manual
‘k’ that decreases the operating pressure in relation to the nominal pressure for higher temperature ranges should be taken into account in the design of PE pipelines. The coefficient can be determined according to the following equation:
Prob= PN x k [bar] Where: k – correction coefficient PN – pipe nominal pressure [bar]
3. Design parameters of PE pipes 3.2. Nominal pressure Among the polyethylene types, which have been applied in the construction of piping systems, we can distinguish between PE 80 and PE 100. MRS parameter (Minimum Required Strength) is used for polyethylene classification in terms of its strength. This parameter is important for determining the design stress required to calculate a thickness of the pipe wall that is resistant to a certain operating pressure.
For the PE pipe classification, see the table below
Klasa PE
sd [MPa]
MRS
C=1.25
Where : Cmin – minimum safety factor for PE pipelines (acc. to ISO12126)
MRS sd = _____ Cmin
Where : p – pipeline nominal pressure dn – pipeline nominal dia.
p.dn e = _______ 2 sd + p
PE 100
10.0
8,0
SDR [-]
33
27,6
26
22
21
17,6
17
13,6
11
9
PE100
PN 5
PN 6
PN 6,3
PN 7,5
PN 8
-
PN 10
PN 12,5
PN 16
PN 20
en
en
dn
en
mm
di
en
mm
di mm
di mm
3,5
83,0
di
en
mm 4,1
81,8
di
en
mm
di
en
mm
di
en
mm
di
en
mm
di mm
en
di mm
90
3,3
83,4
4,3
81,4
5,1
79,8
5,4
79,2
6,7
76,6
8,2
73,6
10,1
69,8
110
4,0
102,0 4,2
101,6 5,0
100,0 5,3
99,4
6,3
97,4
6,6
96,8
8,1
93,8
10,0
90,0
12,3
85,4
125
4,6
115,8 4,8
115,4 5,7
113,6 6,0
113,0 7,1
110,8 7,4
110,2 9,2
106,6 11,4
102,2 14,0
97,0
140
5,1
129,8 5,4
129,2 6,4
127,2 6,7
126,6 8,0
124,0 8,3
123,4 10,3
119,4 12,7
114,6 15,7
108,6
160
5,8
148,4 6,2
147,6 7,3
145,4 7,7
144,6 9,1
141,8 9,5
141,0 11,8
136,4 14,6
130,8 17,9
124,2
180
6,6
166,8 6,9
166,2 8,2
163,6 8,6
162,8 10,2
159,6 10,7
158,6 13,3
153,4 16,4
147,2 20,1
139,8
200
7,3
185,4 7,7
184,6 9,1
181,8 9,6
180,8 11,4
177,2 11,9
176,2 14,7
170,6 18,2
163,6 22,4
155,2
225
8,2
208,6 8,6
207,8 10,3
204,4 10,8
203,4 12,8
199,4 13,4
198,2 16,6
191,8 20,5
184,0 25,2
174,6
250
9,1
231,8 9,6
230,8 11,4
227,2 11,9
226,2 14,2
221,6 14,8
220,4 18,4
213,2 22,7
204,6 27,9
194,2
280
10,2
259,6 10,7
258,6 12,8
254,4 13,4
253,2 15,9
248,2 16,6
246,8 20,6
238,8 25,4
229,2 31,3
217,4
315
9,7
295,6 11,4
292,2 12,1
290,8 14,4
286,2 15,0
285,0 17,9
279,2 18,7
277,6 23,2
268,6 28,6
257,8 35,2
244,6
355
10,9
333,2 12,9
329,2 13,6
327,8 16,2
322,6 16,9
321,2 20,1
314,8 21,1
312,8 26,1
302,8 32,2
290,6 39,7
275,6
400
12,3
375,4 14,5
371,0 15,3
369,4 18,2
363,6 19,1
361,8 22,7
354,6 23,7
352,6 29,4
341,2 36,3
327,4 44,7
310,6
450
13,8
422,4 16,3
417,4 17,2
415,6 20,5
409,0 21,5
407,0 25,5
399,0 26,7
396,6 33,1
383,8 40,9
368,2 50,3
349,4
500
15,3
469,4 18,1
463,8 19,1
461,8 22,8
454,4 23,9
452,2 28,3
443,4 29,7
440,6 36,8
426,4 45,4
409,2 55,8
388,4
560
17,2
525,6 20,3
519,4 21,4
517,2 25,5
509,0 26,7
506,6 31,7
496,6 33,2
493,6 41,2
477,6 50,8
458,4 62,5
435,0
630
19,3
591,4 22,8
584,4 24,1
581,3 28,7
572,6 30,0
570,0 35,7
558,6 37,4
555,2 46,3
537,4 57,2
515,6 70,3
489,4
710
21,8
666,4 25,7
658,6 27,2
655,6 32,3
645,4 33,9
642,2 40,2
629,6 42,1
625,8 52,2
605,6 64,5
581,0 79,3
551,4
800
24,5
751,0 29,0
742,0 30,6
738,8 36,4
727,2 38,1
723,8 45,3
709,4 47,4
705,2 58,8
682,4 72,6
654,8 89,3
621,4
900
27,6
844,8 32,6
834,8 34,4
831,2 41,0
818,0 42,9
814,2 51,0
798,0 53,3
793,4 66,1
767,8 81,7
736,6 100,5 699,0
1000
30,6
938,8 36,2
927,6 38,2
923,6 45,5
909,0 47,7
904,6 56,7
886,6 59,3
881,4 73,5
853,0 90,8
818,4
1200
36,7
1126,6 43,4
1113,2 45,9
1108,2 54,6
1090,8 57,2
1085,6 68,0
1064,0 71,1
1057,8 88,2
1023,6 108,9* 982,2
1400
42,9
1314,2 50,7
1298,6 53,5
1293,0 63,7
1272,6 66,7
1266,6 79,3
1241,4 83,0
1234,0 102,8 1194,4
1600
49,0
1502,0 57,9
1484,2 61,2
1477,6 72,8
1454,4 76,2
1447,6 90,6
1418,8 94,8
1410,4 117,5 1365,0
1800* * upon request
Pressure Systems Uponor Infra - manual | 9
3. Design parameters of PE pipes SDR
33
PE100RC dn
PN 5 en
mm
di
26
PN 6 en
mm
di
21
PN 6,3 en
mm
17
PN 8
di
en
mm
13,6
PN 10
di
en
mm
11
PN 12,5
di
en
mm
9
PN 16
di
en
mm
PN 20
di
en
mm
di mm
90
3,3
83,4
3,5
83,0
4,3
81,4
5,4
79,2
6,7
76,6
8,2
73,6
10,1 69,8
110
4,0
102,0
4,2
101,6
5,3
99,4
6,6
96,8
8,1
93,8
10,0 90,0
12,3 85,4
125
4,6
115,8
4,8
115,4
6,0
113,0
7,4
110,2
9,2
106,6 11,4
140
5,1
129,8
5,4
129,2
6,7
126,6
8,3
123,4 10,3 119,4
160
5,8
148,4
6,2
147,6
7,7
144,6
9,5
141,0 11,8
180
6,6
166,8
6,9
166,2
8,6
162,8
10,7
158,6 13,3 153,4 16,4 147,2 20,1 169,8
200
7,3
185,4
7,7
184,6
9,6
180,8
11,9
176,2 14,7 170,6 18,2 163,6 22,4 155,2
225
8,2
208,6
8,6
207,8
10,8 203,4
13,4
198,2 16,6 191,8 20,5 184,0 25,2 174,6
250
9,1
231,8
9,6
230,8
11,9
226,2
14,8
220,4 18,4 213,2 22,7 204,6 27,9 194,2
280
10,2 259,6
10,7 258,6
13,4 253,2
16,6
246,8 20,6 238,8 25,4 229,2 31,3 217,4
11,4
292,2
12,1 290,8
15,0 285,0
18,7
277,6 23,2 268,6 28,6 257,8 35,2 244,6
295,6
102,2 14,0 97,0
12,7 114,6
15,7 108,6
136,4 14,6 130,8 17,9 124,2
315
9,7
355
10,9 333,2
12,9 329,2
13,6 327,8
16,9 321,2
21,1
312,8 26,1 302,8 32,2 290,6 39,7 275,6
400
12,3 375,4
14,5 371,0
15,3 369,4
19,1 361,8
23,7
352,6 29,4 341,2 36,3 327,4 44,7 310,6
450
13,8 422,4
16,3 417,4
17,2 415,6
21,5 407,0
26,7
396,6 33,1 383,8 40,9 368,2 50,3 349,4
500
15,3 469,4
18,1 463,8
19,1 461,8
23,9 452,2
29,7
440,6 36,8 426,4 45,4 409,2 55,8 388,4
560
17,2 525,6
20,3 519,4
21,4 517,2
26,7 506,6
33,2
493,6 41,2 477,6 50,8 458,4 62,5 435,0
630
19,3 591,4
22,8 584,4
24,1 581,8
30,0 570,0
37,4
555,2 46,3 537,4 57,2 515,6 70,3 489,4
710
21,8 666,4
25,7 658,6
27,2 655,6
33,9 642,2
42,1
625,8 52,2 605,6 64,5 581,0 79,3 551,4
800
24,5 751,0
29,0 742,0
30,6 738,8
38,1 723,8
47,4
705,2 58,8 682,4 72,6 654,8 89,3 621,4
900
27,6 844,8
32,6 834,8
34,4 831,2
42,9 814,2
53,3
793,4 66,1 767,8 81,7 736,6 100,5 699,0
1000
30,6 938,8
36,2 927,6
38,2 923,6
47,7 904,6
59,3
881,4 90,8 818,4 90,8 818,4
1200
36,7 1126,6 43,4 1113,2
45,9 1108,2
57,2 1085,6 71,1
1057,8 88,2 1023,6
1400
42,9 1314,2 50,7 1298,6 53,5 1293,0 66,7 1266,6 83,0
1234,0 102,8 1194,4
1600
49,0 1502,0 57,9 1484,2 61.2 1477,6 76,2 1447,6 94,8
1410,4
WehoPipe RC
WehoPipe RC2+, RC3+
27,6
1800 *
3.3. Selection of fittings for pressure pipes
Table 3.3. Selection of fittings for pipes, taking into account the reduction factors:
Segment fittings supplied by Uponor Infra are further reinforced by increasing the thickness of the pipe walls (decrease of SDR) that are used for their components. The wall thickness of so prepared fitting at the junction to the pipe is the same as the thickness of the pipe. So, standard segment fittings offered you for the pressure piping can be used for pipelines with SDR pressures as specified in the table below. When selecting fittings, please always state the SDR value.
Fittings
Pipeline
elbow
T-pipe
SDR33
PE100
PN5
SDR26 PE100
SDR21 PE100
SDR26
PE100
PN6,3
SDR21 PE100
SDR17 PE100
SDR21
PE100
PN8
SDR17 PE100
SDR11 PE100
SDR17
PE100
PN10
SDR13.6 PE100
SDR11 PE100
SDR13.6
PE100
PN12.5
SDR11 PE100
SDR9 PE100
SDR11
PE100
PN16
SDR9 PE100
SDR9
PE100
PN20
Pressure reduction factors
elbow
T-pipe
0.8
0.65
In cases not covered by the above table, please contact the manufactureρ. Example: Pipeline
Segment elbow, 30°
Segment T-pipe, 90°
dn630 SDR21 PE 100 PN8
dn630 SDR17 PE100
dn630 SDR11 PE100
1 0 | Pressure Systems Uponor Infra - manual
3. Design parameters of PE pipes Cross-section through a pipe/fitting walls at their joint:
PE100 PE80 PE100 PE80 PE100 SDR17 SDR17 SDR17 SDR17 SDR11
PE100 PE100 SDR17 SDR11
PE100 SDR17
PE80 SDR17 pipe - PE100 SDR17 elbow & PE100 SDR17 pipe - PE100 SDR11 elbow (example) 3.4. Thermal linear expansion of PE pipes Thermal coefficient of linear expansion for various materials is as follows:
PE100 SDR11
SDR17
PE80, PE100 SDR17
PE100 or PE80 SDR17 pipes - PE100 SDR11 T-pipe (example) mm m.K
2.4 2.2
PE
mm/Kx m
0.15-0.20
STEEL
mm/K x m
0.01
2.0 1.8 1.6 1.4
Curve of change of thermal expansion coefficient as a function of temperature for Hostalen (source: Basell)
1.2 1.0 0
Expansion loop for small diameter pipelines, dn<160mm
PE80, PE100 PE100 SDR11
Expansion loop for small diameter pipelines, dn<160mm
Polyethylene has a much higher thermal expansion coefficient than steel, cast iron and other traditional installation materials. Such a large thermal expansion does not automatically imply the need for thermal expansion loops for polyethylene pipes. There are two cases available, depending on the operating conditions of the pipeline:
20
30
40
50
60
70
80 oC
Expansion loop for small and large diameter pipelines
1. The pipeline is placed in the ground and the freedom of its movements (as a whole and of any of its fragments) is practically limited to zero. 2. The pipeline is an aboveground installation and there are opportunities for movements of large portions of it.
Pressure Systems Uponor Infra - manual | 11
3. Design parameters of PE pipes In the first case, due to the viscoelastic properties of the material, the thermal stress (the stress induced in the material at a change in its temperature while limiting the freedom of its deformation) going to be relieved especially when considering the long term effects (winter/ summer). Also, one should keep in mind that polyethylene is also characterized by high thermal resistance and therefore the change in the average temperature of the pipe wall is much smaller than the change in temperature of the transported fluid or ambient temperature. Therefore, for a typical case of pipelines laid in the ground, there is no need for thermal expansion loops regardless of the length of the pipeline. In the second case, you should carry out a more detailed analysis of the operating conditions of the pipeline.
Here, one must take into account method of the pipeline support (the best example is the longitudinal support, e,g, pipe in a trough), the distribution of fixed points, the potential impact of additional insulation (polyethylene of colour other than black may not be exposed to long-term effects of UV radiation, since it leads to accelerated aging of the material), nature of the temperature change (fast-cycle, or slow in time, seasonal changes, resulting from the change of the seasons), the length of the pipeline and the temperature distribution in the wall of the pipe and its impact on the level of stress (thermal stress must be assumed with the internal stresses resulting from the temperature distribution in the pipe wall and stresses derived from internal pressure). Therefore, to solve such problems, please contact our technical advisors.
Example: Data
Pipe mounted on a flyover: - Seasonal changes in temperature, ΔT=25 deg C (summer-winter) - length of the exposed pipeline (installed outside the ground) L=100m
Result
Max. possible elongation DL= L x a x DT= 100[m] x 0.16 [mm/m*K] x 25 [K]= 20[mm] x 25= 0.4[m]
Practical way to reduce the effect of linear expansion is the use of a fixed point in the middle of the segment – linear elongation will distribute across two shorter segments and its effect will be smalleρ.
4. Hydraulic calculations for pipes with pressure flow 4.1. Calculation algorithm Design of hydraulic lines with tensioned liquid surface (i.e. pressure flow) involves the determination of the pressure head (or directly pressure value) at a specific point in the network transporting the fluid. In practical applications, for the dimensioning of large, branched networks, complex programs are used that employ optimization methods. Practical design cases related to hydraulic dimensioning of single lines arise from the need to identify: - pressure values at the start of a line section in order to select appropriate parameters of pressure equipment to ensure the required value at the end of the section, or - estimate pressure at the end of a section of the line for the assumed pressure value applied at the starting point. The basic equation describing the liquid flow in pipes, known as equation of continuity or Bernoulli equation has the following form:
1 2 | Pressure Systems Uponor Infra - manual
• (1)
P1
g
+
a.v2 2.g
+z1=
P2
g
+
a.v2 2.g
+z2+ Shstr
P1, P2 – pressure at points No. 1 and No. 2 of the considered pipeline section [Pa] z1, z2 – position head above the comparative level common for both points [m] g - acceleration of gravity (m/s2) - Coriolis coefficient [-] - specific gravity of water [kN/m3] v - average flow velocity [m/s]
a g
This formula describes the relationship between the flow parameters in the individual sections and allows their comparison at any points alongside the pipeline section. The individual elements of the formula have a height dimension and are called, respectively, the pressure head, the velocity head and the position head. Hloss means the sum of all the losses of pressure head that occur over a distance of fluid flow between points No.1 and No.2.
4. Hydraulic calculations for pipes with pressure flow It is described by the following formula:
• (2)
Shstr = hl + Shm = l .
l dw
.
v2 v2 +Sz 2.g 2.g
The first module of the formula describes the amount of losses along the length, which depend on the flow parameters, pipe cross-sectional geometry, roughness of the inner walls of the pipe and the density and temperature of the fluid carried. The second module specifies the total magnitude of the effect of local losses caused by the elements disrupting the flow of liquid. Coefficients ζ take their values according to the type and parameters of the element responsible for the point loss. Both modules have a height dimension [m] and are called the hydraulic loss head.
• (3)
1 l
=- 2 . log
2.51 k + . Re l 3.71.dm
g - acceleration of gravity [m/s2] v - average flow velocity [m/s] dw - average ID of the pipeline [m] l - length of the section between points No. 1 and No. 2 l - coefficient of linear losses [-] z - coefficient of local losses [-] In practical applications, due to low flow velocity in water and sewage networks, the velocity head is omitted in the calculations. The main task is to determine the hydraulic head loss. Losses in length are the meaningful magnitude in most practical cases. Local losses are omitted in many cases because they are not significant or are considered as a fraction of the losses in length. Standard absolute roughness value of PE pipes k is 0.01 mm. For the flow conditions and parameters of pipes made by Uponor Infra, value of the hydraulic resistance coefficient, which represents the resistance resulting from fluid contact with the pipeline wall, is calculated from the Colebrook-White equation:
• (4)
R e=
v.dw
n
k - absolute roughness of pipeline walls [m] Re - Reynolds number, calculated from the formula:
dw - internal diameter of pipeline [m] v - average flow velocity [m/s] - coefficient of kinematic fluid viscosity [m2/s]
Bernoulli equation is non-linear, implicit dependence of many variables. In order to solve it, it is necessary to indicate clearly the calculation objective, as a single desired parameter.
In the Uponor Infra, pressures at the beginning and end of the section are indicated as possible calculation objectives. Finding solutions is performed as an iterative process.
ν
4.2. Coefficient of kinematic viscosity The value of the coefficient of kinematic viscosity is dependent on the type of the liquid and its temperature. The following table shows viscosity coefficients for the temperature range from 2 to 25°C. In the Uponor Infra software, you can input liquid temperature in the range from 0 to 60°C. The values of kinematic viscosity coefficient n [m2/s], depending on the temperature and the concentration of suspended matter in the wastewater, are shown in Table below. In the current design practice, a constant kinematic viscosity
coefficient for water and wastewater is usually adopted: n = 1.31 * 10-6 m2/s at water (wastewater) temp. equal to 10 °C. Tem. [°C]
Water n
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
Waste water Suspended matter concentration 100 mg/l 300 mg/l 500 mg/l 2.17 x 10-6 3.17 x 10-6 4.17 x 10-6 1.60 x 10-6 1.76 x 10-6 1.92 x 10-6 1.33 x 10-6 1.37 x 10-6 1.41 x 10-6 1.02 x 10-6 1.02 x 10-6 1.04 x 10-6 0.90 x 10-6 0.91 x 10-6 0.92 x 10-6
4.3. Comparison of the pressure losses and flow capacities of pipelines made of various materials The objective of the calculations is to compare pressure losses in the pressure pipelines made of various materials. The calculation also takes into account the change of the technical condition of the inner surface of pipelines operated over several years.
For clarity, the same ID’s were adopted for the comparisons (ID = 500 mm) for each type of pipe. Adopted kinematic viscosity coefficient n = 1.31 * 10-6 m2/s water (wastewater) temperature equal to 10°C. Other data used in the calculations are contained in the following tables. Pressure Systems Uponor Infra - manual | 1 3
4. Hydraulic calculations for pipes with pressure flow Pipeline material
Absolute roughness k [mm]
Linear losses DHl [m H2O]
Increase of pressure losses in relation to PE pipes [%]
PE
0.01
34.2
0.0
New
0.1
36.5
6.7
Old
3.0
44.8
28.0
New
0.1
36.5
6.7
Old
3.0
44.8
28.0
New
0.05
35.6
4.1
Old
0.07
36.0
2.9
Modular cast iron
Steel
PVC
Pressure losses in pressure pipelines transporting water (without local resistance) made of different materials (D = 500mm, Q = 200 l/s, v = 1.0 m/s, L = 1000m). For the calculation of the linear loss factor, the ColebrookWhite equation was used (equation No. 9). The calculation results show clearly that PE pipes are characterized by a much lower flow resistance and a much
higher flow capacity in comparison with lines made of other materials, regardless of the pipeline operating time. These differences, in favour of PE pipes, are much larger with a longer service life of the pipeline. This is mainly due to the low absolute roughness of the pipe, which practically does not change during operation.
4.4. Examples of hydraulic calculations You can use the Uponor Infra software to perform hydraulic calculations.
1 4 | Pressure Systems Uponor Infra - manual
The software allows performing hydraulic calculations for several lines connected in series.
4. Hydraulic calculations for pipes with pressure flow 4.5. The phenomenon of water hammer 4.5.1. General – course of the phenomenon Water hammer is a sudden pressure change in a pressure conduit, caused by rapid changes in velocity of liquid flow. Due to the viscoelastic properties of thermoplastic pipes, the wave velocity and pressure increase are much lower in comparison with such materials as steel, cast iron or concrete. It can therefore be concluded that the use of plastic pipes is beneficial to minimize the negative effects of this phenomenon, and thus the safety and durability of the installation. The immediate cause of water hammer phenomenon is a sudden change in velocity caused by a sudden closing or opening a valve, starting or shutting-off a pump, etc. The sharp decline in velocity in cross-section results in a sudden increase in pressure in the immediate vicinity and is called positive water hammeρ. The excited inertial forces lead to an increase in the pressure of the liquid being braked. The slowdown includes another portions of the liquid. A pressure and velocity discontinuity area is formed, separating liquid with decreased velocity and higher pressure from those of the fluid areas where conditions of steady flow still prevail. This discontinuity area is called the shock wave front, which is being moved in the line at a speed c in a direction opposite to the direction of fluid flow under steady conditions. This wave is reflected at the points of local disturbances (e.g. fitting components, tees, etc.) and returns.
Due to the wave nature of the phenomenon (it is an elastic wave) you can determine its period T, the maximum pressure increase Δp, and the duration t. Power dissipation of water hammer, leading to the gradual disappearance, takes place as a result of the flow resistance (many times larger than at the steady flow), fluid compressibility and reaction of the pipe wall. When velocity increases, pressure decreases - negative water hammer - the phenomenon is analogous to that described above. However, you should remember that at too low operating pressures, negative phase created in the first phase of the phenomenon can lead to cavitation. In the situation when the absolute pressure reaches a value equal to the vapour pressure at a given temperature, liquid will rapidly transit from the liquid to the gaseous state. The resulting steam bubbles increase their volume, and after exceeding the critical conditions, they close (implode) in an explosive way. This phenomenon is accompanied by characteristic crackling and popping. Cavitation adversely affects fittings and piping.
4.5.2. Hydraulic calculations - basic parameteres Maximum pressure increase (simple water hammer). The value of maximum pressure increase (decrease) be calculated from Żukowski equation:
Δp can
Δp = r.c.Δυ [Pa]
Where:
r – liquid density [kg/m3], c – v elocity of wave propagation [m/s], Δυ – velocity change [m/s]. 4.5.3. Velocity of wave propagation The velocity of wave propagation c is dependent on modulus of volume elasticity K of the liquid, the liquid density r, the inside diameter of the pipe D, the wall thickness e and the
modulus of elasticity of the pipe wall material E It is calculated from the Korteweg equation, denominator of which takes into account the effect of the pipe deformability:
c=
K r K 1+ D e.E
[m/s]
Pressure Systems Uponor Infra - manual | 1 5
4. Hydraulic calculations for pipes with pressure flow Under the term ‘pipe diameter’ D, it is meant the inside diameter of a thin-walled pipe (wall thickness of a few millimetres). In the case of PE pipes with larger wall thicknesses, operating conditions of a loaded pipe will be slightly different. Therefore, the Korteweg equation assumes average diameter:
The modulus of elasticity of the pipe material E should take into account the dynamic nature of the phenomenon, and can be determined from the following dependence:
D=
Dz+Dw =Dz-e [m], 2
E=
Where:
Dz = outer diameter [m], Dw = inside diameter [m], e = wall thickness [m].
Where:
E0 1-n2
E0 = Young’s modulus of
the pipe wall material – determined by classical methods [Pa],
n = Poisson ratio [-] Table 4.5.3.1. Water density values ρ and water modulus of volume elasticity K for the selected temperatures and ranges of operating pressures from 1-105 Pa to 25-105 Pa
Temperature T [0C]
Density r [kg/m3]
Modulus of volume elasticity [N/m2]
0
999.84
1.868·109
10
999.70
1.961·109
20
998.20
1.997·109
Values of E0 and n depend on the type of material of which the pipe is made and can be read from appropriate manufacturer’s tables or catalogues. Below, there are some examples of the E0, n and c values of for Polyethylene pipes made by Uponoρ. For comparison, values for other commonly used materials are also given.
Table 4.5.3.2. Approximate values of the Young's modulus E0, Poisson ratio ν and wave velocity c for selected materials
Material
E0 [Pa]
[-]
n
c [m/s]
PE100
1.2·109
0,40
212 ÷ 424
Steel
2·1011 – 2.15·1011
0,28
1260
Cast iron
9·1010 – 1.60·1011
0,25
1185
1 6 | Pressure Systems Uponor Infra - manual
4. Hydraulic calculations for pipes with pressure flow Table 4.5.3.3. Values of wave velocity c for water at 10 °C, depending on SDR for the Uponor polyethylene pipes
SDR [-]
33
26
22
17
11
9
291
357
392
Wave velocity c [m/s]
Material Polietylen PE100
21
211
237
4.5.4. Wave period Wave period is related to the length of the pipe L and velocity c by the following dependence:
257
T=
263
2L [s] c
The value of wave period is necessary, inter alia, to determine whether we are dealing with a simple or complex water hammeρ.
4.5.5. Non-simple (complex) water hammer – pressure increase A factor that often decides on the course of events is the valve closing time tC (time of step change in velocity). If the closing time is shorter than the wave period (tC ≤ T) - we call the phenomenon simple, and the pressure increase is calculated from the Joukowsky equation. If the closing time is longer than the wave period (tC > T) - the phenomenon is referred to as non-simple. In such a situation, the pressure
2.ρ.υ0.L Δp = [Pa] tz
increase is slower and is reduced by the return of the reflected wave. The pressure increase can be calculated from the Michaud's formula, if the increase value is less than 220% of the initial (operating) pressure value, or in the conditions of the linear velocity change in the pipe.
r – gęstość cieczy [kg/m3] υ0 – v elocity in steady motion (before the
occurrence of the phenomenon) [m/s]
L – length of the pipe [m] tz – closing time [s]
Pressure increases caused by water hammer are lower than in the simple case, thus extending the closing time of closure is the simplest, yet most effective way to reduce the pressure increase. In the cases used in practice for large diameter pipes, closing times of shut-off valve are so long that in most cases they will be larger than the wave period.
Thus, under operating conditions, the non-simple water hammer phenomenon will occur more frequently and will be characterized by smaller pressure increase. Simple water hammer will be associated with emergencies, for sudden changes in flow velocity.
Pressure Systems Uponor Infra - manual | 1 7
4. Hydraulic calculations for pipes with pressure flow Table 4.5.5.1. Examples of the pressure increases induced by water hammer for the selected piping materials Assumptions: initial velocity v = 1.5 m/s, length of pipeline 1200 m, temperature 10ºC
Material
Pressure increase Δp [Pa] Simple water hammer Closing time tz < 5 s
Non-simple water hammer Closing time tz = 20 s
PE100
487 354
179 946
Steel
1 889 433
179 946
Cast iron
1 776 967
179 946
4.5.6. Methods of weakening water hammer phenomenon The adverse effects of water hammer phenomenon can be prevented by using various methods, such as: - lengthening the time of valve closing / opening, extending the pump impeller start up and shut down times - so that the occurring phenomenon would be a non-simple water hammer, soft start , - installation of aeration valves in the pipe - their function is to open up when the pressure in the pipe drops below atmospheric pressure (the pressure drop phase, i.e. negative wave), and the air is sucked into the pipe, which reduces the pressure increase as a result of energy loss due to compression; preventing cavitation is an additional advantage of this solution, - installation of an air/water accumulator in the system, located in the immediate vicinity of the valve causing water hammer – air cushion of the tank reduces pressure increase and shortens the duration of the event and causes the energy loss due to the compression and expansion,
1 8 | Pressure Systems Uponor Infra - manual
- installation of high-pressure safety valves in the pipe - their function is to open in case of exceeding the allowable pressure; as a result, there is a partial reduction in velocity and pressure increase is lower in the line despite the closure of the main valve, - when connecting together lines made of various materials - it should be noted here that,in the case of a pipeline consisting of pipes connected in series and made of various materials, the phenomenon can be strengthened or weakened (detailed calculation by numerical methods is possible, in order to determine the ratio of length of a section made of e.g. steel [wave speed c = 1250 m/s] to the pipe section made of PE (wave velocity for PE 100, c = 209 ÷ 405 m/s), for which pressure increase weakening occurs if the PE pipe is located in the immediate vicinity of the water hammer phenomenon uprising - in this case, the PE pipe will act as a pressure increase damper and will reduce the pressure increase, Δp.
4. Hydraulic calculations for pipes with pressure flow Table 4.5.6.1. Recommended diameters and the number of safety valves for pressure pipelines.
Pipeline dia. [mm]
Safety valve dia. [mm]
Safety valve dia.
300
125 - 150
1
400
125 - 150
2
500
125 - 150
1
600
200
1
900
200
2
1000
200
2-3
1200
200
3-4
Diameters of the most commonly used valves are up to 200 mm
4.5.7. Water hammer in piping networks – reflection and transformation method For piping networks, or pipeline conduits with components, where energy dissipation of unsteady motion can occur, computational methods are much more complicated. Among these, there are analytical methods – Reflection and Transformation method and numerical method (Method of Characteristics and Finite Element method). Methods of numerical (approximate) solution of the systems of equations of motion and continuity, describing the phenomenon of water hammer are created by the use of numerical methods. Field of knowledge concerning the use of numerical methods in solving problems of hydraulics is currently in a phase of dynamic growth, and no numerical tools have been obtained so far that would allow for a universal description of the water hammer phenomenon. Reflection and Transformation method is a relatively simple analytical method, the results of which describe the phenomenon with sufficient accuracy for engineering
practice. It consists in analyzing the problem at the network characteristic points. It is assumed that the wave formed on the water hammer closing moves within the network and undergoes transformation when encountering the individual elements (part of pressure increase enters into the farther part of the system) and reflection (portion of the wave is reflected and returns to the closure). Each element of fittings (elbow, T-pipe, the change in diameter, etc.) has its own reflectance and transformation factoρ. So a complex network should be considered by analyzing the pressure wave increase or reduction at the individual characteristic points. For details of the reflection and transformation method, see the engineering literature, e.g. M. Niełacny Uderzenia hydrauliczne, Poznań 2002.
4.5.8. Calculation example – PE piping In a pipeline made of PE100 with OD = 710 mm, having wall thickness e = 42.1 mm (SDR = 17) and length L = 1800 m, flows water at a flow rate of v = 2.5 m/s. Water temperature is T = 10ºC, operating overpressure in the line is p0 = 0.80 MPa. The following is to be calculated: maximum pressure in the event of a sudden closure of a valve installed at the end of the line, the minimum pressure
in the event of a sudden opening of the valve installed at the end of the line, the time after which the disturbance wave moves to the beginning of the line, and the valve closing time, at which pressure increase in the line does not exceed the value of Δp = 0.25xp0.
Pressure Systems Uponor Infra - manual | 1 9
4. Hydraulic calculations for pipes with pressure flow Solution Simple positive water hammer To calculate the pressure increase Δp in the event of a sudden closure of the valve, i.e. the theoretical time tz≤T we use the Joukowsky-Allievi equation Δp = p.c.Δυ [Pa] where c can be calculated from the Korteweg equation.
K p
c=
1+
D . K e E
Reading the water density value of ρ = 999,7 kg/m3 and the modulus of elasticity for water K = 1.961.109 N/m2 from Table 1 and the modulus of elasticity PE100 E = 1.2.109 N/m2 and the Poisson ratio of υ = 0,40 from Table 2. we obtained the following:
E=
E0 1.2.109 = = 1.43.109 Pa 2 1-0.402 1-υ
Using the formula for the disturbance wave velocity c and pressure increase Δp, the following values were obtained:
1.961.109 1400.57 999,7 c= = = 293 m/s 9 4.77 0.6679 . 1.961.10 1+ 0.0421 1.43.109 Δp = ρ.c.υ0= 999.7.293.2.5 = 732280.3 N/m2 = 0,732Mpa
The initial value of overpressure in the pipe will be: pn = p0 +Δp = 0.732 + 0.8 = 1.532 MPa, so pn = 1.91.p0 > pn = 1.25.p0. Simple negative water hammer The pressure wave is created by the sudden opening of the valve at the end of the pipe under pressure. We are dealing with a pressure drop. Formulae are the same as for the positive impact. To calculate the pressure drop Δp in the case of a rapid opening of the valve, i.e. the theoretical time tz≤T we use the Joukowsky-Allievi equation:
Δp = ρ.c.Δυ [Pa] Where c can be calculated from the Korteweg equation
K
c=
ρ
.K 1+ D e E
Reading the water density value of r = 999.7 kg/m3 and the modulus of elasticity for water K = 1.961.109 N/m2 from Table 1 and the modulus of elasticity PE100 E = 1.2.109 N/m2 and the Poisson ratio of υ = 0,40 from Table 2. we obtained the following:
E=
2 0 | Pressure Systems Uponor Infra - manual
E0 1-υ2
=
1.2.109 = 1.43.109 Pa 1-0.402
4. Hydraulic calculations for pipes with pressure flow Using the formula for the disturbance wave velocity c and pressure increase Δp, the following values were obtained:
c=
1.961.109 999.7
= 0.6679 . 1.961.109 1+ 0.0421 1.43.109
1400.57 = 293 m/s 4.77
Δp = ρ.c.υ0= 999.7.293.2.5 = 732280.3 N/m2 = 0,732Mpa The initial value of overpressure in the pipe will be pn = p0 -Δp = 0.8-0.732 = 0.068 MPa. Non-simple water hammer To avoid the pressure rise above the assumed value of Δp ≤ 0,25.p0 the valve should be closed slowly - then the induced phenomenon will be a non-simple water hammer ρ. In order to calculate the time within which the valve can be safely closed, we use the following Michaud formula for a nonsimple positive water hammer:
tz =
2.ρ.υ0.L
Δp
[Pa]
dop
After substituting the figures, we obtain
tz =
2.999,7.2.5.1800 = 45 s 0.25.0.8.106
hence the conclusion that the closing time should not be less than the calculated tz = 45 s. In the event of a simple water hammer (tz = 0) the disturbance wave moves to the beginning of the pipe within
t=
L 1800 = = 6.14 s c 293
Answer: the pressure increase at a positive simple water hammer will be Δp = 0.732 MPa, in such a situation, the pressure rise will be pn = 1.532 MPa,at closing, the disturbance wave moves to the beginning of the pipe within t = 6.14 s, The nonsimple water hammer phenomenon with the rise equal to the assumed value of Δp = 0,2 MPa (which gives the overpressure in the area of the closure equal to pn = 1.0 MPa), is invoked at the time of closing more than tzΔ ≥ 45 s. In the case of non-simple water hammer, a definitely smaller increase was achieved. It requires, however, a sufficiently long closing time.
4.5.9. Calculation example – cast iron conduit In a pipeline made of nodular cast iron of Class K9 with nominal diameter of DN = 700 mm, length L = 1800 m, flows water at a flow rate of υ = 2.5 m/s. Water temperature is T = 100C, and operating positive gauge pressure in the line is p0 = 0,80 MPa. The following is to be calculated: - maximum pressure in the event of a sudden closure of a valve installed at the end of the line, - the minimum pressure in the event of a sudden opening of the valve installed at the end of the line, - the time after which the disturbance wave moves to the beginning of the line, and - the valve closing time, at which pressure increase in the line does not exceed the value of
Δp = 0.25xp0.
Pressure Systems Uponor Infra - manual | 2 1
4. Hydraulic calculations for pipes with pressure flow Solution Simple positive water hammer To calculate the pressure increase Δp in the event of a sudden closure of the valve, which is the theoretical time tz = 0, we use the Joukowsky-Allievi equation
Δp = ρ.c.Δυ [Pa] Reading the water density value of r = 999,7 kg/m3 and the modulus of elasticity for water K = 1.961.109 N/m2 from Table 1 and the velocity of wave movement for cast iron c = 1185 m/s from Table 2. we obtained the following:
Δp = ρ.c.υ0 = 999.7.1185.2.5 = 2961611 N/m2 = 2.962MPa The initial value of overpressure in the pipe will be pn = p0 +Δp = 3.762 MPa, thus pn = 4.7.p0 > p0 = 1.25.p0. To avoid the pressure rise above the assumed value of Δp ≤ 0,25.p0 the valve should be closed slowly. Simple negative water hammer The case of the negative water hammer occurs in a situation of rapid valve opening at the end of the pipe under pressure. Computational methods are the same as for the positive water hammeρ. To calculate the increase of pressure Δp in the event of a sudden closure of the valve, i.e. the theoretical time tz = 0, we use the Joukowsky-Allievi equation
Δp = ρ.c.Δυ [Pa] Reading the water density value of r = 999,7 kg/m3 and the modulus of elasticity for water K = 1.961.109 N/m2 from Table 1 and the velocity of wave movement for cast iron c = 1185 m/s from Table 2. we obtained the following:
Δp = ρ.c.υ0 = 999.7.1185.(-2.5) = -2961611 N/m2 = -2.962MPa The initial value of the overpressure in the conduit will amount to pn = p0 + Δp = -2.162 MPa - this pressure value is impossible to obtain. In the conditions of pressure drop in the line to a vapour pressure, cavitation will occur, and it will be particularly violent. Non-simple water hammer n order to calculate the time within which the valve can be safely closed, we use the following Michaud formula for a nonsimple positive water hammer
tz = After substituting the figures, we obtain
tz =
2.ρ.υ0.L
Δpdop
2.999.7.2.5.1800 = 45 s 0.25.0.8.106
hence the conclusion that the closing time should not be less than the calculated tz = 45 s. In the event of a simple water hammer (tz = 0) the disturbance wave moves to the beginning of the pipe within
t=
L c
=
1800 1185
= 1.52 s
Answer: the pressure increase at a simple water hammer will be Δp = 2.962 MPa, in such a situation, the there will be overpressure of pn = 3.762 MPa, at closing and the disturbance wave will move to the beginning of the pipe at time t = 1.52 s, The non-simple water hammer phenomenon with the rise equal to the assumed value of Δp = 0,2 MPa (which gives the overpressure in the area of the closure equal to pn = 1.0 MPa), is invoked at the time of closing exceeding tz ≥ 45 s. In the case of non-simple water hammer, a definitely smaller increase was achieved. It requires, however, a sufficiently long closing time.
2 2 | Pressure Systems Uponor Infra - manual
4. Hydraulic calculations for pipes with pressure flow Analysis of the results of sample calculations The following table shows the results of calculations. Assumptions: initial velocity 2.5 m/s, length of line 1800 m, operating pressure 0,8 MPa, temperature 10ºC Table 6. Summary of the results of calculations for the examples in the text.
Type of conduit Characteristic
PE 100 PN 10, 710x42.1 SDR 17
Nodular cast iron DN 700
Velocity of disturbance wave propagation c [m/s]
293
1185
Disturbance wave period T [s]
6.14
1.25
Pressure rise at simple water hammer tz < T Δp [MPa]
0.732
2.962
45
45
Max pressure value in a cross-section pmax [MPa] – simple positive water hammer
1.532
3.762
Min pressure value in a cross-section pmin [MPa] – simple negative water hammer
0.068
CAVITATION *
Min closing time required for non-simple water hammer tz [s]
* - pressure value impossible to achieve in practice - in the event of a pressure drop to the vapour pressure value, cavitation occurs.
Summarizing the results of the calculations specified in the Table above, for comparable conditions in steady motion (i.e. pressure, velocity, length and diameter), we can clearly see much smaller increase in pressure caused by the water hammer in the PE 100 pipe.
Smaller values of pressure rise are caused by the material properties, expressed by the values of velocity of the disturbance wave propagation c. In a comparable cast iron pipe and in a simple negative impact situation, a very disadvantageous phenomenon of cavitation occurs in the pipe.
Pressure Systems Uponor Infra - manual | 2 3
4. Hydraulic calculations for pipes with pressure flow 4.6. Nomograms for hydraulic calculations Nomogram for determining the unit pressure drop for PE SDR 26 pipes, at a temperature of 10°C and roughness k = 0.01 mm acc. to Colebrook-White equation Flow rate Q [dm3/s] 0,2
0,4
0,6
0,8
1
2
4
6
8
10
20
40
60
80
100
200
400
1000
600 800
2000
4000
10000 100
6000 8000
80
80
60
60
40
40
20
20
10
10
8
8
6
6
4
4
2
2
1
1
0,8
0,8
0,6
0,6
0,4
0,4
0,2
0,2
0,1 0,1
0,2
0,4
0,6
0,8
1
2
4
6
8
10
20
40
60
80
100
200
400
600 800
1000
2000
Unit pressure drop H [‰]
Unit pressure Unit pressure drop H [‰]
0,1 100
0,1 10000
4000
6000 8000
4000
6000 8000
Flow rate Q [dm /s] 3
o
Nomogram for determining the unit pressure drop for PE SDR 21 pipes, at a temperature of 10°C and roughness k = 0.01 mm acc. to Colebrook-White equation Flow rate Q [dm3/s] 100
0,2
0,4
0,6
0,8
1
2
4
6
8
10
20
40
60
80
100
200
400
1000
600 800
2000
10000 80
60
60
40
40
20
20
10
Unit pressure drop H [‰]
100
80
10
8
8
6
6
4
4
2
2
1
1
0,8
0,8
0,6
0,6
0,4
0,4
0,2
0,2
0,1
0,1
0,2
0,4
0,6
0,8
1
2
4
6
8
10
20
40
Flow rate Q [dm3/s]
2 4 | Pressure Systems Uponor Infra - manual
60
80
100
200
400
600 800
1000
2000
4000
6000 8000
Unit pressure drop H [‰]
0,1
0,1
10000
4. Hydraulic calculations for pipes with pressure flow Nomogram for determining the unit pressure drop for PE SDR 17 pipes, at a temperature of 10°C and roughness k = 0.01 mm acc. to Colebrook-White equation Flow rate Q [dm3/s] 0,2
0,4
0,6
0,8
1
2
4
6
8
10
20
40
60
80
100
200
400
600
800
1000 100
80
80
60
60
40
40
20
20
10
10
8
8
6
6
4
4
2
2
1
1
0,8
0,8
0,6
0,6
0,4
0,4
0,2
0,2
0,1 0,1
0,2
0,4
0,6
0,8
1
2
4
6
8
10
20
40
60
80
100
200
400
600
800
Unit pressure drop H [‰]
Unit pressure drop H [‰]
0,1 100
0,1 1000
Flow rate Q [dm3/s]
Nomogram for determining the unit pressure drop for PE SDR 13.6 pipes, at a temperature of 10°C and roughness k = 0.01 mm acc. to Colebrook-White equation Flow rate Q [dm3/s] 100
0,2
0,4
0,6
0,8
1
2
4
6
8
10
20
40
60
80
100
200
400
600
800
1000 100 80
60
60
40
40
20
20
10
10
Unit pressure drop H [‰]
80
8
8
6
6
4
4
2
2
1
1
0,8
0,8
0,6
0,6
0,4
0,4
0,2
0,2
0,1 0,1
0,2
0,4
0,6
0,8
1
2
4
6
8
10
20
40
60
80
100
200
400
600
800
Unit pressure drop H [‰]
0,1
0,1 1000
Flow rate Q [dm3/s]
Pressure Systems Uponor Infra - manual | 2 5
4. Hydraulic calculations for pipes with pressure flow Nomogram for determining the unit pressure drop for PE SDR 11 pipes, at a temperature of 10°C and roughness k = 0.01 mm acc. to Colebrook-White equation Flow rate Q [dm3/s] 0,2
0,4
0,6
0,8
1
2
4
6
8
10
20
40
60
80
100
200
400
600
800
Unit pressure drop H [‰]
80
1000 100 80
60
60
40
40
20
20
10
10
8
8
6
6
4
4
2
2
1
1
0,8
0,8
0,6
0,6
0,4
0,4
0,2
0,2
0,1 0,1
0,2
0,4
0,6
0,8
1
2
4
6
8
10
Flow rate Q [dm3/s]
2 6 | Pressure Systems Uponor Infra - manual
20
40
60
80
100
200
400
600
800
0,1 1000
Unit pressure drop H [‰]
0,1 100
5. Installation of pressure pipes in the ground 5.1. Pipe work with the soil â&#x20AC;&#x201C; flexible and rigid pipes During the installation, pressure pipe works like a gravity pipe (hollow), which is subject to external loads (soil, groundwater, traffic loads). Particular care should be taken when installing pipelines with thin walls, such as SDR33. The following table summarizes the range of pressure pipes and the corresponding peripheral stiffness (modulus E = 1200 MPa was assumed for the calculations, same as for PE100). The behaviour of pipe under the load is dependent on its rigidity. Plastic pipes belong to the group of flexible tubes. Under a load, a flexible pipe exerts pressure on the surrounding soil. This triggers a response in the surrounding soil, which in turn resists further deformation of the pipe.
SDR
SN
33
2.5
26
5.3
21
10.4
17
20.3
The amount of the pipe deformation may be limited by appropriate selection of the soil material and construction method. Therefore, the load bearing properties of flexible pipes depend upon on the method of their installation and the type of soil. In the rigid pipes, load is transmitted mainly by the internal strength of the pipe material, and when the load exceeds the limit value, the tube is destroyed. Standards for rigid pipes consider the fracture toughness in a standard test as the basis, which is the maximum permissible magnitude of the pipe load.
Flexible pipes
Rigid pipes
5.2. Soil classification Classification of soils used for the installation of pipelines according to ENV 1046:2001
Soil group Type of # soil
1
loose 2
loose
3
Typical name
Symbol*
Characteristic features
Examples
Mid-graded gravel, fine to coarse gravel
(GE) [GU]
Steep graining curve, domination of one faction
Crushed stone, gravel, river and sea gravel, moraine gravel
Well-graded gravel, fine to coarse gravel
[GW]
Poorly graded gravel
(Gl) [GP]
Continuous graining curve, several fractions Stepped graining curve, some fractions are missing
Scoria, volcanic ash
Mid-graded sand, fine to coarse sand
(SE) [SU]
Steep graining curve, domination of one faction
Dune sands, deposited, valley and trough sands
Well-graded sand, fine to coarse sand
[SW]
Continuous graining curve, several fractions
Poorly graded sand
(Sl) [SP]
Stepped graining curve, some fractions are missing
Silty gravel, silty all-in aggregate with discontinuous [GM] (GU) grain size Clayey gravel, clayey all-in aggregate with discontinuous [GC] (GT) grain size Silty sand, sandy & silty mix with discontinuous grain size
Discontinuous graining curve, silty fraction content Discontinuous graining, fine clay content
YES
Moraine, terrace and coastal sands
YES
Weathered gravel, rock rubble, clayey gravel YES
Discontinuous graining, fine silt content
Hydrated sand, clayey sand, sandy loess
Clayey sand, sandy & clayey mix with discontinuous grain [SC] (ST) size
Discontinuous graining, fine clay content
Clayey sand, alluvium clay, marl
Inorganic silt, fine sand, stone [ML] (UL) dust, silty and clayey sand
Poor stability, rapid mechanical reaction, zero to low plasticity
Loess, sandy clay
[SM] (SU)
Can be used as backfill
YES Average to very good stability, not Inorganic clay, very plastic [CL] (TA) CTL) too slow mechanical reaction, low to Alluvium marl, clay clay (TM) average plasticity * Designations have been taken from two sources. Designations in square brackets [..] are derived from the British standard BS 5930. Designations in parentheses (..) are derived from the German standard DIN 18196.
cohesive
4
Where the substrate is a mixture of several types of soil, presence of one of the soils can be the basis for classification. Pressure Systems Uponor Infra - manual | 2 7
5. Installation of pressure pipes in the ground 5.3. Construction of trenches Open trenches without wall protection a) Open trenches without wall protection and with inclined slopes. Excavations down to 4.0 m and with no occurrence of ground water and landslips, and without overburden loading within soil wedge may be made with the following safe slope inclinations:
H
x
Allowable inclination of slopes for open trenches without boarding Type of soil
Max. inclination of slopes H:x
in very cohesive soils
2:1
in stony soils
1:1
in remaining cohesive soils
1:1.25
in non-cohesive soils
1:1.5
H
H
x
In other cases, inclination of the trench slopes should be specified in the construction project. b) Open trenches with vertical walls and without protection.
FUNDAMENT
Such excavations may only be performed in the dry ground, where the area is not loaded with embankments or construction equipment at the trench edges and within a strip with a width equal to at least the depth of the trench, H. Material excavated from the trench should be stored at a distance of not less than 0.5 m from the edge of the excavation, and the dimensions of the dump of ground should not pose any threat to the stability of the trench walls.
4.0 m,
in cohesive soils
1.5 m,
in other soils
1.0 m.
f
DROGA
d
H Distances to roads d at Road traffic may take place a distance not less than that specified by the following relation:
FOUNDATION
fu + 0.5
b H : tg
DROGA
x a
Open trenches with vertical supported walls Protection of the excavation walls should be performed strictly according to the construction project. Special care should be taken in the case of trenches made near highways or buildings.
Where: b -d istance between the edge of a roadway and the edge of trench in [m], H - depth of the trench, u - i nternal friction angle of the soil.
H b
FUNDAMENT
Max. depth of trench H
in rocky, solid and not cracked grounds
H
a
Allowable inclination of vertical trenches without boarding Type of soil
b
b
a
2 8 | Pressure Systems Uponor Infra - manual d
ROAD
5. Installation of pressure pipes in the ground Distances to buildings (foundations) The distance from the bottom edge of the trench to the vertical wall of a building foundation situated above the bottom may not be less than that determined by the following formula: a ≥ (H - h + 0.3) : tg u + 0.5
f
When maintaining of these distances is impossible, a detailed analysis of the safety status is required, both for the excavation protective system and for the adjacent roadway or structure. The excavation protection system should be left in such cases, and soil in the trench carefully compacted to the ratio as required in the works project.
Where: a - distance between the bottom of the trench and a vertical wall of a building foundation situated above the bottom of the trench, H, u - as above h - depth of the adjacent building foundation calculated from the land datum to the datum of the building foundation.
f
The minimum distance of two adjacent supported vertical excavations In simultaneous excavation of two trenches next to each other, the minimum distance between their adjacent edges may not be less than that specified by the following formula:
fu
d ≥ (H - 1) : tg
It is recommended that a deeper excavation would be made earlieρ. Other conditions for the safe execution of excavations are discussed in BN-83/8836-02. The last layer of soil on the bottom of the trench, with a thickness of 0.2 m, should be removed immediately before laying pipeline, paying attention to the elevation of the pipeline (it is unacceptable to ‘overdepth’ the trench).
Where: H - depth of the deeper trench calculated from the land datum to the datum of the bottom of the excavation, internal friction angle of the soil. u
f
Pressure Systems Uponor Infra - manual | 2 9
5. Installation of pressure pipes in the ground 5.4. Terminology 5 4
Hz
3
H Hz Hz
bs
H H bs bs
Bottom stabilization (if required)
b
Bottom stabilization (if required) Bottom stabilization
5 5 4 2 4 3 1 3 2 2 1 1
(if required) b
b
1. Substrate (subcrust) 2. Basic filling 3. Upper filling 4. Backfill 5. Subsoil H - Depth of the trench Bs - Width of the trench Hz- Height of covering
Min values of bs de [mm]
bs [mm]
de < 300 300 < de < 900 900 < de < 1800
200 300 400
Width of the trench at the height of the pipe joint should not be greater than the required width of the pipe with regard to the method of connection (welding, socket connection, etc.), plus additional space resulting from the need to filling compaction. Wider trenches may be necessary in cases such as larger depths or poor stability of walls of an unprotected excavation.
5.5. Methods of embedding pipes in the ground
A key aspect in the design before performing the excavation and installation of the pipe is to determine the ground conditions under which the pipeline will be installed.
DO NOT COMPACT
DO NOT COMPACT DO NOT COMPACT
Filling to a height of at least 0.3 m above the top edge of the pipe is recommended to be made of a material with such parameters as for the subcrust (groups 1-4) and grain sizes as shown in Tab.
3 0 | Pressure Systems Uponor Infra - manual
(1) Substrate: compacting to approx. 90% SPD Approx. layer thickness 100-150 mm, gravel, sand, all-in aggregate, silt (Groups 1-4 from the soils table), compacted manually. Pipes should be laid on the bottom of the trench in such a manner that they should lay uniformly supported on the subcrust along their entire length. The strength parameters of the substrate may not be lower than those adopted in the project documentation (static and strength calculations of the pipeline). Moreover, they should maintain the hydraulic gradient. (2),(3) Filling: basic and upper; compacting to 90-95% SPD Filling should be laid symmetrically on both sides of the pipe in layers with a thickness of not more than 0.2 m, paying particular attention to its careful compacting in the pipe support zone. During the compaction of the filling in this area, maintain due diligence in order to avoid raising the pipe. To the filling compaction, use of lightweight surface vibrators (up to 100 kg) is recommended. Using the vibrator directly above the pipe is unacceptable; you can only use a vibrator when the soil layer with a thickness of at least 0.3 m was laid above the pipe.
5. Installation of pressure pipes in the ground Subsoil may be used for the filling in the pipe embedding area provided that it meets all of the following criteria: a) it does not contain particles larger than acceptable for a given pipe diameter, according to Table 4; b) it contains no lumps bigger than double the particle size limit for a given application in accordance with Table 4; c) it is not a frozen material; d) it does not contain any foreign particles (such as asphalt, bottles, cans, pieces of wood); e) when compacting is required - it is a susceptible material.
(4) Backfill TGreen areas: when installing a pipeline under green areas, you can use the subsoil (from the trench). In this case, no special requirements are made on the minimum compacting index.
Where no specific information on subsoil is available, it is assumed that the compaction index is between 91% to 97% as determined acc. to the Standard Proctor Method (SPD). Requirements for maximum particle size of soil used for the installation of pipes are specified in table 5.4.1 below. Pipe nominal dia. DN
Max. particle size [mm]
DN < 100
15
100 < DN < 300
20
300 < DN < 600
30
600 < DN < 1800
40
Under roads & streets: it is recommended to use the same soil for the backfill as for the filling material. You can use vibrators weighing up to 200 kg to compact the backfill. - SPD compaction index acc. to the highway engineering requirements. Swelling soils may not be used for the upper backfill layers (with a thickness adapted to the depth of the freezing zone) for the pipelines installed under roads and streets.
filling upper filling basic filling subcrust
5.6. Drainage of excavations During the installation work, the excavation should be kept drained. Lowering of the groundwater level in the excavation should be made in all cases where ground water prevents or hinders the excavation or embedding of pipeline. Lowering of the groundwater level should be carried out in such a way that the soil structure would not be compromised in the substrate of the installed pipeline or near the adjacent structures. The groundwater level should be reduced by at least 0.5 m below the bottom of the trench. Lowering of the groundwater level must be performed round-the-clock due to
adverse effects of groundwater level variations on the ground structure on the bottom of the excavation. Moreover, the excavation should be protected against inflow of rainwater and the components of the trench protecting walls must protrude at least 0.15 m above the adjacent area and the site area should be profiled with slope enabling easy water outflow outside the trench. A detailed method of the excavation drainage system should be specified in the construction project.
Pressure Systems Uponor Infra - manual | 3 1
5. Installation of pressure pipes in the ground 5.7. Recommended methods of soil compacting The strength properties of the pipe filling area generally depend upon the type of soil material used for its implementation and the degree of compaction obtained. Different compaction indices can be achieved through the use of various devices and the appropriate number of layers. Degree of soil compaction determined by the Standard
Proctor Method (SPD, Standard Proctor Density) obtained in three compaction classes. i.e. ‘W’, ‘M’ and ‘N’, depending upon the soil class, classified in accordance with Table 5.2., are summarized in Table 5.7.1. below.
NOTE. Soil compaction degrees acc. to Standard Proctor Test are specified acc. to DIN 18127. Table 5.7.1. Soil compaction degree acc. to Standard Proctor Test for the individual compaction classes
Compaction class
N None M Medium W High
Class of soil used for filling 4 SPD [%]
3 SPD [%]
2 SPD [%]
1 SPD [%]
75 ÷ 80 81 ÷ 89 90 ÷ 95
79 ÷ 85 86 ÷ 92 93 ÷ 96
84 ÷ 89 90 ÷ 95 96 ÷ 100
90 ÷ 94 95 ÷ 97 98 ÷ 100
Table 6 summarizes the recommended maximum thicknesses of layers and the number of passes required to achieve the specified compaction grade for various types of devices and material (soil groups) used as filling material. The table also includes the recommended minimum thickness
of layers on the top of pipe, for which the use of a machine for compacting soil directly above the pipe is possible. Details summarized in Table 6 should be considered as guidelines and details on the compaction method should be consulted with the designer and contractor.
Table 5.7.2. Recommended thickness of layers and number of passages at soil compaction
No. of passages for the compaction class
Max thickness of layers after compaction [m] for the individual soil groups (see Table 1)
Density ‘W’ (High)
Density ‘M’ (Medium)
1
2
3
4
3
1
0.15
0.10
0.10
0.10
0.20
3
1
0.30
0.25
0.20
0.15
0.30
Plate 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
Vibratory roller 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
Dual vibratory 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
Heavy triple roller (non-vibratory) min 50 kN/m
6
2
0.25
0.20
0.20
—
1.00
Equipment
Compacting with legs or manual compactor min 15 kg Vibratory compactor min 70 kg
3 2 | Pressure Systems Uponor Infra - manual
Min thickness of layer above the pipe top before compaction [m)
5. Installation of pressure pipes in the ground 5.8. Compacting quality control Conformity with the design assumptions should be confirmed by at least one of the following methods: - close supervision of the compacting procedures; - verification of initial deflection of the installed pipe; - on-site testing of the soil compaction.
After any repairs and additional connections, pay special attention to compact the displaced excavation backfilling and filling material to approximately the same degree as the ground directly adjacent to the area of works.
5.9. Work performed at low temperatures When performing excavation work at low temperatures, soil at the bottom of the trench may freeze. Installation of pipelines on the frozen soil layer is not allowed. The portion of soil should be removed directly before laying the pipeline and replaced by a layer of not frozen, loose
soil with grain size up to 20 mm (up to 16 mm for crushed aggregate). This layer should be compacted up to compaction index 95% SPD. Backfilling the excavation with soil containing frozen lumps is unacceptable.
5.10. Removal of trench protection When the excavation edges (acc. to BN- 83/8836-02) are too close to a highway or building, it may be required to leave the excavation protection. In the remaining cases, it should be removed. Remove the trench protection made of wooden components, steel profiles or box elements along with backfilling the trench. Box type protection creates very favourable conditions for the implementation of trenches since it does not pose a risk to adjacent structures (there are no ground vibrations as for the driven walls) and ensures maintaining the ratio of soil compaction. Moreover, these enclosures ensure the safe conduct of work. Pulling the driven trench protection components out can cause loosening of the trench filling and backfill of the pipeline. The result of this relaxation is reduction of the pipe load capacity and damage to the road surface as a result of additional subsidence of soil filling and backfill. In order to reduce the adverse effects of pulling out the trench protection components, especially for pipelines laid under the streets, it is recommended to increase the requirements for the minimum compaction index for subcrust, filling and backfill to 97% SPD. Use of equipment that does not cause vibrations or vibratory compactors with as low vibration amplitude as possible
should be an additional factor that limits the adverse effects of pulling the excavation protection components.
5.11. Installation of pipes in the parallel system Pipes in the parallel systems in regular trenches should be installed with the sufficient distances between them in order to provide access of filling compacting equipment between the pipes. Provide the space between pipes with a width exceeding the width of compacting equipment of 150 mm in order to ensure its free operation. The filling material in the area between the pipes should be compacted to the same degree as that in the area between the pipe and trench wall. When laying parallel pipes in gradual trenches (see Fig. 4), the filling material should be loose and compaction class W should be specified.
1 Parallel lines in gradual trench 1. Highly compacted soil (Class W)
Pressure Systems Uponor Infra - manual | 3 3
5. Installation of pressure pipes in the ground 5.12. Soil replacement When there are rocks, stones or hard soils present, soil in the bottom of the excavation area must be replaced. At the bottom of the trench, quicksand and the like may occur, organic soils or soils showing a tendency to volume changes under the influence of moisture. In such cases, the engineer should decide on the scale of the soil replacement under the pipe and method of pipe embedding on the backfill soil. Each situation of this type
should be considered individually based on own experience in similar work in order to determine the scope of the soil replacement and the type of material to be used for subcrust. When soil replacement is to be used, including any unintentional excessive deepening of the trench, use the same subcrust material as is planned to be used in the filling area and it should be compacted to achieve Class ‘W’.
5.13. Embedding pipelines in low-bearing soils In cases of expected significant land subsidence, or anticipated changes in the soil structure, you can use geotextiles as shown in Fig. 7. However, if large displacement of the soil grains is anticipated, such a solution may be insufficient. In such cases, you should request the opinion of an expert. Among other special conditions at the stage of laying pipes, you can encounter flowing or standing groundwater appearing at the bottom of the trench or the quicksand effect at the bottom of the trench. In such cases, lowering of the ground water level is carried out by applying the pump wells or drain installed on the pipe-laying stage and functioning until the pipe is not covered with soil to a degree sufficient to counteract the
uplift pressure or the slipping of the excavation walls. Grain size of soil in the subcrust, filling and backfill areas should be chosen so as to avoid migration of fine soil fractions from the trench zone to the adjacent ground and reverse phenomenon in water saturation conditions. Any migration of soil grains between the zones can lead to a weakening of the support at the bottom and the side zones of the pipe. The use of the relevant filter mats, as shown in Fig. 5. can prevent transport of fine soil fractions. If the filter mats are joined, provide a lap with a width not less than 0.3 m. Not joined mats should be applied with a lap of a width not less than 0.5 m.
Fig. 5.13.1. — Protection against migration of fine soil fractions
Fig. 5.13.2. — Trench bottom reinforced with wooden structure
1
1
2
3
Key: 1 Filling zone 2 Subcrust 3 Filter mat
3 4 | Pressure Systems Uponor Infra - manual
1
1
22
2
3
3
Key: 1 Filling zone 2 Subcrust 3 Filter mat
3
5. Installation of pressure pipes in the ground 5.14. Geotextiles If the soil is weak or soft, so that safe work of people in the trench is not possible, strengthening of the trench bottom before subcrusting is required. Strengthening the bottom of
the trench can be made in the form of e.g. a wooden structure or geotextile mats.
Fig. 5.14.1. Typical use of geotextile mats. Fig. 5.14.1.a — Geotextile reducing uneven settling of the pipe embedding area
Fig. 5.14.1.b — G eotextile as a partial ground-sill, casing and strengthening
Fig. 5.14.1.c — Geotextile as a complete groundsill, casing and strengthening
Fig. 5.14.1.d — G eotextile constituting anchoring preventing uplift pressure of the pipe
1- geotextile
Pressure Systems Uponor Infra - manual | 3 5
5. Installation of pressure pipes in the ground 5.15. Installation of PE pipes in casing pipe PE pipes, due to their strength, do not require protection with casing pipes. Casing pipes are used when any formal requirements exist, e.g. those related to track culverts (PKP), where the operation requirements (e.g. due to repair), recommend free access
to the installed line without the need to disturb the soil conditions. PE pipes can be installed in casing pipes with so called spacers or can be freely installed in the casing pipes.
Fig. 5.15.1. PE pipeline in casing pipe with spacers.
EMBANKMENT/GROUND
casing pipe
WehoPipe culvert
spacers
WehoPipe pipes can be installed in the road culverts inside other pipes – made of steel or concrete. We recommend installation of the WehoPipe pipes together with spacers in the culverts. Resistance of the spacers to pipe crushing
Pipe DN
(pipes are filled with liquid) should be decided by the spacer manufactureρ. Spacing of the spacers/skids (i.e. distance between them) can be assumed as follows:
Distance between skids in m
Up to 160 mm
1.5 – 2
180 - 1200 mm
2
1200 - 1800 mm
1.2 – 1.5
5.16. Use of support blocks Pipe fittings offered by Uponor Infra, do not require additional support by means of ferroconcrete blocks (structural) in most cases. However, the decision on the use of support blocks should take into account the soil conditions, type of flow, possible water hammer, temperature changes, etc., and it should be made by the designer. Uponor Infra recommends the use of fittings with thicker walls in relation to the main pipe in the pressure pipelines: fitting should be made of SDR one degree lower (see paρ. 3.2), allowing the transfer of axial forces without the
3 6 | Pressure Systems Uponor Infra - manual
use of support blocks. However, be aware of the correct and exact execution of assembly especially around fittings (type of soil and compaction). At a change of the pipeline route direction, you should sometimes abandon the segment arcs and make a gentle bending of the pipeline instead.
5. Installation of pressure pipes in the ground 5.17. Anchoring wall transitions for PE pipes (fixed point) The proposed anchoring transition is tight up to 5m of water, provided that the system of rubber flanges Frank is used. In addition, concrete wall must be made of waterproof concrete. 1
1. Bulkhead â&#x20AC;&#x201C; waterproof concrete 2. PE anchoring flange 3. Frank rubber flange 4. WehoPipe
2 3
1
L
2 3 4
di
de
do
de
Scope of application for pipe dia.
Pipe wall thickness
Anchoring flange
SDR11
Type of profile
SDR26
SDR17
dn=de
d2
h
L
e
e
e
dn
mm
mm
mm
mm
mm
mm
mm
mm
-
90
110
17
160
3.5
5.4
8.2
90-97
A
18
160
4.2
6.6
10.0
110-121
A
140
25
165
4.8
7.4
11.4
125-140
A
140
160
25
165
5.4
8.3
12.7
140-159
A
160
180
25
165
6.2
9.5
14.6
160-180
A
180
200
30
165
6.9
10.7
16.4
180-199
A
200
230
35
190
7.7
11.9
18.2
200-224
A
225
250
40
190
8.6
13.4
20.5
225-249
A
250
280
40
190
9.6
14.8
22.7
250-279
A
280
320
45
190
10.7
16.6
25.4
280-314
A
315
360
50
190
12.1
18.7
28.6
315-354
355
410
50
230
13.6
21.1
32.2
355-399
L B
400
482
19-47
120
15.3
23.7
36.3
400-449
B
450
535-585
19-47
120
17.2
26.7
40.9
450-499
B
3
500
585
22-51
120
19.1
29.7
45.4
500-559
B
560
685-725
25-55
120
21.4
33.2
50.8
560-629
B
4
630
685-725
30-55
120
24.1
37.4
57.2
630-709
B
710
805
36-60
120-125
27.2
42.1
710-799
B
800
905
42-60
120-135
30.6
47.4
800-899
B
900
1005
53-65
120-140
34.4
53.3
900-999
B
1000
1100
61-89
140-160
38.2
59.3
1000-1150
B
1200
1300
65-65
160-180
45.9
1200-1350
B
PE anchoring flange
Frank A profile
di
130
de
110 125
do
d2
e
4
A
Frank B profile steelsteel bands bands
steelsteel bands bands
Pressure Systems Uponor Infra - manual | 3 7
1 2
5. Installation of pressure pipes in the ground 5.18. Connection of pipes to rigid structures When the pipeline passes through structures such as buildings, drainage wells or support blocks, then tolerance for settling differences should be considered in the joint design. Materials such as polyethylene, are flexible enough to tolerate displacements occurring and may be connected
as shown in Fig. 12. In order to minimize the stress of shearing forces and bending moments, pipes protruding from the rigid structures should be effectively supported on the subcrust.
Key: 1. Subcrust and filling 2. Subsoil – well compacted material (Class W) 3. Concrete wall 4. WehoPipe 5. PE anchoring flange and sealing profile
5.19. Installation of pipes in long and short sections Long sections Due to their flexibility and homogeneous connections, PE pipes can be installed in long sections. PE pipes are then connected outside of the trench and the connected sections can be transferred into the prepared trench. In this way, the earthworks and welding of pipes can be carried out independently. This helps to reduce installation costs and speeds up installation.
This installation method is often practiced in the use of PE pipes. Short sections In the heavily built-up areas where connection of pipes in long sections is impossible, welding of pipes can be carried out inside the trench. This installation requires a full synchronization of earthworks and pipe connection.
5.20. Distances between supports Longitudinal support is the most preferred support method for PE pipelines conducted on flyovers. However, if making the longitudinal support is technically
infeasible, the implementation of the following algorithm basing on the example of DN (OD) 500 SDR21 pipe allows you to calculate the maximum distance between supports.
INPUT: (assumed max. deflection, y; calculate distances between supports, Lmax): OD = 500 mm SDR = 21 Standard Dimension Ratio E = 200 Young’s modulus, N/mm2. (for 50 years) wL = 1 000 specific gravity of liquid, kg/m3 m = 0.7 material stress from deflection (0.7 for pressure pipelines), N/mm2 y= 25 deflection (recommended: 25mm)
Young's modulus E is assumed depending on the expected life of the pipeline. The table allows you to find the needed modulus values as a function of temperature and time. 3 8 | Pressure Systems Uponor Infra - manual
2
4
3.(OD -ID ) π.σm 8.(w +w ).OD 4
Lmax =
p
s
OUTPUT: ID = 452.2 moment of inertia, mm Ia = 1 .015E+09 pipe weight, mm4 wp = 37.1 pipe weight, kg/m pipe wf = 160.6 liquid weight, kg/m pipe Lmax = 4194 distance between supports, mm
π.ID
wf = wL .
I=
π
64
4
f
. (OD4-ID4)
Modulus (E) vs. time for PE pipes (N/mm2) Temp. (C) -15 5 15 23 37 50
0h 1668 1161 952 805 593 448
1h 892 622 507 426 306 218
10 years 432 305 252 214 158 118
>=50 years 386 272 224 190 140 105
E modulus values depend on the grade of PE material. The following table shows the approximate values developed on the basis of a specific grade of PE.
6. PE pressure pipe connections The most commonly used methods of pressure pipe joining include: Method of pipe joining
Range of diameters
Butt welding
Dn 63- 1800 mm
PE pipes connected in long sections
Flange connections
Dn 63- 1800 mm
Connections with fittings and other pipe types, also connecting of long sections of PE pipes together
Electrofusion
Dn 63- 630 mm (up to Dn1200 on request)
6.1. Butt welding Butt welding is a process by which material of the two ends of pipes is joined under high temperature and pressure and penetrates forming a uniform structure at the point of contact. It is a relatively simple method, but to get high-quality welds with the parameters of the connected pipes, high precision in its execution is required. The aim of this study is to provide basic information on the butt welding and help in understanding processes occurring during the use of this method, and a description of the safe and proper making of the welds.
PE pipe welding process is performed as follows: • Ends of two lines are fixed in the welding machine equipped with a hydraulic system enabling movement of one part of the machine and producing the contact pressure. T • he pipe ends are bevelled using special cutters. • An electrically heated metal plate is inserted between the pipe ends. • The pipe ends are pressed against the hot plate with adequate pressure for a predetermined time.
Application
Connecting of PE Pipes in confined and narrow areas, where pipe welding is impossible
Thermoplastics such as PE, heated to a temperature of 200 220 °C and subjected to an appropriate pressure, change their state of aggregation from solid to plastic. Both ends of properly cut and hot pipes come into contact and are subjected to a pressure and combine to form uniform and tight connection after cooling. A properly made joint has the same strength characteristics as the pipes being connected.
• When the pipe ends soften sufficiently, the plate is removed
and the pipe ends are connected and subjected to pressure in order to obtain the weld. The pressure exerted on the pipe ends during welding and the duration of the operation are strictly defined. • After cooling of the joint, pipes are removed from the welding machine and you can start preparing for the next welding operation. Typical length of PE pipe sections are L = 12.5 m
6.1.1. Welding process parameters The phases of the welding process are characterized by various parameters, many of which are determined by the nominal pipe wall thickness ‘e’ or the nominal diameter of the
pipe ‘OD’, denominated as de. Welders supplied by Uponor Infra are designed to join the following pipes: PE DN from 63 up to 1800 mm
List of technical parameters used during welding. (Note: The following information should be considered only as general.)
I. Welding temperature
May not deviate from: T = 210 °C ± 10 °C measured continuously with thermal sensoρ.
II. Pressure during welding
P = 0.17 N/mm2 ± 0.02 N/mm2 In practice, force created by material resistance is added to the pressure P.
III. Upheating time (flash formation time)
Time required to form a flash described as ‘A’ (width of the bead on one side of the plate), is specified depending on the type of pipe.
IV. Bead width "A"
A = 0.5 mm + 0.1 x e
V. Pressure during soaking
It should be 0, max 0.01 N/mm2
VI. Soaking time
t = 15 x e ± e
VII. M ax. switching time between soaking and the start of exertion pressure on the pipe ends
The switching time is a critical parameter, depending on the pipe diameter ‘de’ t ≤ 3 sec + 0.01 x de (sec)
VIII. Max. time to obtain the proper pressure
t ≤ 3 sek + 0.03 x de
IX. Pressure during welding
Pa1= 0.18 N/mm2 ± 0,01 N/mm2 (for PE)
X. Pressure during cooling
Pa3= 0.18 N/mm2 (for PE)
XI. Time of cooling under pressure (welding time)
t min = 10 + 0.5 x e (min)
(approx.) (sec)
(sec)
Pressure Systems Uponor Infra - manual | 3 9
6. PE pressure pipe connections Fig. 6.1.2.1. shows an overview of the various phases of the welding process and the course of pressure change as a function of time during the welding of pipes.
p Pa2
Pf2
Pa1 ta1
ta2
tf1
ta
tf2
t
Pa1 Pa2 Pf2 ta1. ta2 ta tf1 tf2 tf tu
(MPa) pressure during upheating of pipe ends; high and low values; (MPa) pressure during welding; (s) pressure exertion time(two phases); during upheating; (s) total upheating time; (s) time to obtain required pressure; (s) cooling time (under pressure); (s) total cooling time; (s) switching time.
tf t
The process parameters, such as: • temperature • pressure • time factors except the temperature of the upheating plate are associated with the nominal diameter and pressure of the pipeline.
The welding process is used for connecting: • straight sections of pipelines; • s traight sections of pipelines with pipe fittings allowing flange connections.
6.1.2. Welding equipment The following types of welding machines are used for connecting pipes of various diameters:
Type of machine
Range of PE pipe dia.
KWH Tech 160
40 do 160 mm
KWH Tech 250
63 do 250 mm
KMT 315
90 do 315 mm
KWH Tech 500
200 do 500 mm
KMT 630
355 do 630 mm
WHA 800
450 do 800 mm
WHA 1200
710 do 1200 mm
PT 1600
1000 do 1600 mm
Detailed data on the Uponor Infra welders are included in our offeρ. The complete set of Uponor Infra equipment for welding consists of the following components:
• Machine frame for accurate axial alignment of the ends of welded pipes; • Rotary cutting device providing proper alignment of pipe ends; • Heating plate with control elements, allowing the maintenance of proper welding temperature; • Special fixture for welding flange fittings to pipe ends; 4 0 | Pressure Systems Uponor Infra - manual
• Moving part (slide), used for moving and contacting welded
pipes; • Operating manual for the machine and welding process (attached to all types of welding machines made by Uponor Infra). Uponor Infra welding machines for butt welding of pipes are supplied with a table setting out the parameters of the process, i.e., pressure, temperature and time of the operation. All parameters were determined based on thorough research, which allowed us to determine the optimal values,applied later in practice. The result is the best possible weld strength, virtually equal to the strength of the pipe.
6. PE pressure pipe connections 6.1.3. PE pipe connections by butt welding at low temperatures In addition to the principles contained in the GENERAL TERMS OF WORK OF THE UPONOR INFRA SP. Z O. O. SERVICE TEAM, the following conditions are to be met: 1. The workplace shall be protected from the weather (rain, hail, snow, wind) by a tent. 2. At very low temperatures, the space under the tent shall be heated to a temperature above freezing point by using a hot air bloweρ.
Compliance with these conditions guarantees a joint that meets the strength and tightness requirements. The Uponor Infra Sp. z o. o. service team has the equipment necessary to work in winter conditions.
6.1.4. Welding sequence Before you start welding, perform the following preparatory work strictly in accordance with the operating manual: • Prepare the workplace, set the welding machine and install sun or waterproof shields, as required; place of welding should be protected from the weather (rain, hail, snow, wind) by a tent.
• Prepare a process control sheet for the technical
parameters that occur during welding. • Prepare any special marking (if required by the contract).
When you are ready, you can start welding of pipelines. The welding is carried out by performing the steps (described below) in accordance with the instructions attached to each welding machine supplied by Uponor Infra: 1. Insert the pipe ends to the welding mounts adapted to the diameter of the welded pipe. Tighten the clamping screws, setting the pipe in position, diagonally. The ends of the tubes protrude approximately 30 - 100 mm from the fixture. In order to avoid bending, the welded pipes are supported on both ends. To minimize the drag force, the movable part of the welder has special bearings installed. 2. Insert the cutter between the pipes. Then, the pipe ends are pressed against the cutter disk head by means of hydraulic cylinders. In order to obtain a suitably smooth surface, reduce the contact pressure gradually. 3. Insert the heating plate between the ends of the aligned pipes. The plate melts the pipe ends, forming a bead around their circumference, 1.0 - 7.0 mm wide (depending on the pipe wall thickness). You can find value of the pressure force (including the drag force) to be used in the table attached to
each weldeρ. After forming the bead, clamping force is reduced to almost zero, followed by a non-pressure soaking. 4. Then, move the pipe ends away from the heating plate and remove the plate carefully, without touching the molten surfaces. The pipe ends are to be connected with adequate clamping force. The force increases within tf1time, and then within tf2 time (i.e. cooling time), it remains constant. Do not accelerate the cooling process by spraying wateρ. 5. After the lapse of the cooling, you can open the clamping covers and remove the pipes from the welding machine. Avoid rapid manipulation of the pipeline, and do not perform pressure tests before material cools down completely (to ambient temperature).
6.1.5. Butt Welding Procedure Control sheet During welding, the important technical parameters of the process must be recorded in a process control sheet. After completion of the welding process, all recorded parameters should be compared with the values determined by
specifications. Each weld is numbered and requires acceptance (by entering YES in the Control Sheet). If a welded joint cannot be approved, remove it and make a new one.
Pressure Systems Uponor Infra - manual | 4 1
6. PE pressure pipe connections
Min cooling time
mm
17 16 15 14 9
sek.
Final width of flash
sek.
Pipe series design. installation section design.
13
Date of completion
12
REMARKS
11
Accepted/rejected yes/no
10
Welder’s signature
Welded joint completed
WELDER OPERATOR; Uponor Infra certificate No.
CONSTRUCTION SITE INSPECTOR
tel. SITE MANAGER
Site manager’s signature
Min welding time
N sek. sek. sek.
Joint No.
4 2 | Pressure Systems Uponor Infra - manual
mm
Construction
m
Pipe length
Nominal wall thickness
± 0,01
0,18
± 10
°C -
Acceptable tolerance:
1 No. of parameter
Pipeline
Plate temp.
210
Pressure during heat-up
Required value
3
Heat-up time
mm
5 4
Width of flash A
2
de= PN=
Formation of joint
Soaking time
N/mm2 sek.
Max time of plate removal
6
Max time of pressure raise
7
8
Weld. machine pressure
INSTALLATION DATA
PE PIPELINE BUTT WELDING CONTROL SHEET
tel.
Inspector’s signature
18
Table 6.1.5.1. Control sheet for technical parameters occurring during welding
6. PE pressure pipe connections 6.2. Flanged connections Flanged connections are used for connecting PE pipes with fittings or other types of pipes (e.g., steel, cast iron), and long sections of PE pipes with each other. A flanged end of PE pipe consists of 3 components: • Stub-end – PE component welded to the pipe • Steel or cast iron flange • Set of screws and nuts
Metal flanges and bolts with nuts supplied by Uponor Infra Sp. z o. o. are hot-dip galvanized in order to provide corrosion protection. Uponor Infra Sp. z o. o. offers steel flanges. For the pipelines installed in the ground, both steel and cast iron flanges can be used. In the pipelines installed outside the ground (e.g. suspended, underwater pipelines, etc.), where high stresses and bending moments at the connection points may occur, use of only steel flanges is recommended.
View of a flanged connection
b
D
k
d6
PE
dn d3
d4
Steel
d2xn
h1
Z1
Stub-end
25 32 40 50 63 75 90 110 125 140 160 180 200 225 250 280 315 355 400 450 500 560 630 710 800 900 1000 1200
SDR 17
SDR 11
dn=de
d3
d4
z1*
e
h1
e
h1
mm
mm
mm
mm
mm
mm
mm
mm
33 40 50 61 75 89 105 125 132 155 175 180 232 235 285 291 335 373 427 514 530 615 642 737 840 944 1047 1245
58 68 78 88 102 122 138 158 158 188 212 212 268 268 320 320 370 430 482 585 585 685 685 805 900 1005 1110 1330
50 50 50 50 50 50 80 80 80 80 80 80 100 100 100 100 100 120 120 120 120 120 120 120 120 120 140 140
3.0 3.8 4.5 5.4 6.6 7.4 8.3 9.5 10.7 11.9 13.4 14.8 16.6 18.7 21.1 23.7 26.7 29.7 33.2 37.4 42.1 47.4 53.3 59.3 67.8
12 14 16 17 18 18 18 18 20 24 24 25 25 25 30 33 46 46 60 64 70 85 90 100 120
2.3 3.0 3.7 4.6 5.8 6.9 8.2 10.0 11.4 12.7 14.6 16.4 18.2 20.5 22.7 25.4 28.6 32.2 36.3 40.9 45.4 50.8 57.2 64.6 72.6 81.7 90.2
9 10 11 12 14 16 17 18 25 25 25 30 32 32 35 35 35 40 46 60 60 80 82 85 95 100 120
Pressure Systems Uponor Infra - manual | 4 3
6. PE pressure pipe connections PN 10 dn
DN
PN 16
flange
bolts
D
d6
k
b
d2
n
flange M
bolts
D
d6
k
b
d2
mm
mm
mm
mm
mm
n
M
mm
mm
mm
mm
mm
mm
mm
20
15
95
28
65
14
14
4
M12
95
28
65
14
14
4
M12
25
20
105
34
75
14
14
4
M12
105
34
75
14
14
4
M12
32
25
115
42
85
14
14
4
M12
115
42
85
14
14
4
M12
40
32
140
51
100
16
18
4
M12
140
51
100
14
18
4
M12
50
40
150
62
110
16
18
4
M16
150
62
110
16
18
4
M16
63
50
165
78
125
16
18
4
M16
165
78
125
16
18
4
M16
75
65
185
92
145
16
18
4
M16
185
92
145
16
18
4
M16
90
80
200
108
160
18
18
4
M16
200
108
160
18
18
8
M16
110
100
220
128
180
18
18
8
M16
220
128
180
18
18
8
M16
125
100
220
135
180
18
18
8
M16
220
135
180
18
18
8
M16
140
125
250
158
210
18
18
8
M16
250
158
210
18
18
8
M16
160
150
285
178
240
18
22
8
M20
285
178
240
18
22
8
M20
180
150
285
188
240
18
22
8
M20
285
188
240
18
22
8
M20
200
200
340
235
295
20
22
8
M20
340
235
295
20
22
12
M20
225
200
340
238
295
20
22
8
M20
340
238
295
20
22
12
M20
250
250
395
288
350
22
22
12
M20
405
288
355
24
26
12
M24
280
250
395
294
350
22
22
12
M20
405
294
355
24
26
12
M24
315
300
445
338
400
26
22
12
M20
460
338
410
32
26
12
M24
355
350
505
376
460
28
22
16
M20
520
376
470
35
26
16
M24
400
400
565
430
515
32
26
16
M24
580
430
525
38
30
16
M27
450
500
670
517
620
38
26
20
M24
715
517
650
46
33
20
M30
500
500
670
533
620
38
26
20
M24
715
533
650
46
33
20
M30
560
600
780
618
725
42
30
20
M27
840
618
770
55
36
20
M33
630
600
780
645
725
42
30
20
M27
840
645
770
55
36
20
M33
710
700
895
740
840
50
30
24
M27
910
740
840
63
36
24
M33
800
800
1015
843
950
56
33
24
M30
1025
843
950
74
39
24
M36
900
900
1115
947
1050
62
33
28
M30
1125
947
1050
82
39
28
M36
1000
1000
1230
1050
1160
68
36
28
M33
1255
1050
1170
90
42
28
M39
1200
1200
1455
1260
1380
80
39
32
M36
1485
1260
1390
*
48
32
M45
4 4 | Pressure Systems Uponor Infra - manual
6. PE pressure pipe connections 6.3. Electrofusion fittings In the electrofusion system, electric heating wire is embedded in the PE fitting sockets. Electric energy passing through the wire melts the surrounding material, which in turn melts the
pipeline by contacting it. The electrofusion fitting is connected to the pipeline in this way.
1. Pipe ends are inserted into the fitting before joining.
3. Material surrounding the wire begins to melt.
4. Area of molten material expands approaching the pipeline surface.
5. Heat is transferred to the pipeline walls and material begins to melt.
6. The molten material solidifies on the border of the cold zone, thereby sealing the area of the melt. Further heating causes an increase in pressure in the molten material.
2. Activation of electric energy
7. The pressure of the molten material reaches an optimal value at the end of the heating phase. Appearance of the molten material in the control holes indicates the completion of the welding process.
Pressure Systems Uponor Infra - manual | 4 5
7. Leak proof test of pressure pipelines 7.1. General PE pipeline tightness method should take into account the phenomenon of material creep. Leak proof test procedure includes the following stages: • the initial stage comprising a period of relaxation • pressure drop test • basic leak proof test Initial stage: Flush and vent the pipeline, equalizing the pressure inside the pipeline to atmospheric pressure and wait for 60 minutes until the stress relaxation in the pipeline. After this period, you should fast (no longer than within 10 min.) and continuously raise the pressure to the level of STP (System Test Pressuremeaning the test pressure; mostly, STP = 1.5 x PN). Maintain the STP for 30 min. by pumping water continuously or at short intervals. During this time, you should visually inspect the pipeline in order to identify possible leaks. Over a period of 1h, do not pump water and allow the section under test to extend as a result of the light viscoelastic creep. At the end of the initial stage, reduce the pressure in the pipeline If the pressure drops during the initial phase of more than 30% of the STP, you must stop the test and attempt to determine the cause of excessive pressure drop, which may be related to a leak or a change in temperature. After finding the causes of excessive pressure drop, reduce the pressure to atmospheric pressure and wait 60 minutes before repeating the test.
4 6 | Pressure Systems Uponor Infra - manual
Integrated leak proof test Leak proof test should be performed with properly vented pipeline. You can evaluate the air content in the interior of the tested section by performing the following steps: • at the end of the initial stage, depressurize the pipeline of Δp = 10-15% STP by draining water from the tested section; • measure the volume of drained water (DV) accurately; • calculate the maximum water loss, DVmax DVmax =1.2 x Δp x (1/Ew+D/(e+Er)) If DV is higher than DVmax, interrupt the test and vent the pipeline thoroughly again after reducing the pressure to atmospheric pressure. Basic leak proof test Viscoelastic creep induced by STP stress is interrupted by the integrated pressure drop test. A sudden decrease in the internal pressure leads to contraction of the PE pipeline. Observe for approximately 30 minutes (basic leak test) and record the growth of internal pressure caused by the contraction of the pipeline. The basic leak proof test can be considered successful if the pressure change curve tends to increase and within 30 minutes shows no decline. If the pressure change curve falls down, it means a leak in the tested section. Then, we recommend checking all mechanical connections before visual inspection of welded joints and repeat the entire leak proof test (including the preliminary stage) after the removal of all leakages.
8. Relining of pressure pipelines with PE pipes Relining consists of introducing interconnected PE pipes into the repaired conduit, which thus constitute a new, completely tight conduit. Over the past 10 years, the problem of improving the pipelines become even more important. The pipeline systems of various purposes have to meet certain requirements of the operational nature (physical, chemical, biological and biochemical) throughout their lifetime. It depends on many factors, such as the appropriate design, construction,
materials used and the service life. Keeping pipelines in operation requires also a well-organized management. In addition to regular checking condition of the equipment and their ongoing maintenance, you may need to perform some improvement work. The improvements are carried out when there is a need to improve the operating parameters of the conduits. This may require repair, renewal or replacement of old pipelines.
Repair of pressure pipelines with PE pipes can be carried out for the pipe diameters from 90 to 1800mm. This type of retrofitting is often applied to STEEL or CAST IRON pipelines. The purpose of retrofitting is to restore the technical
parameters (such as pressure, flow capacity), which have deteriorated due to corrosion, damage to the structure of the pipeline or leakages on the connections.
8.1. Preparatory work
• Analysis of the route of the pipeline on the basis of the
project and profile of the existing pipeline and on-site inspection • Identification of the location and number of installation trenches. Size of the installation excavations will depend on the depth of the pipeline embedding and the type of the trench protection selected: i.e. wide or narrow spatial excavation • Assessment of the technical condition of the pipeline section to be repaired (whether any lateral movements of pipes, subsidence, deformation of the cross-section, etc. occurred or not) • Removal of any structural breakages, corrosion overhangs,
post-welding overhangs, etc. from the pipeline
• Selection of PE pipe with the appropriate technical
parameters - outer diameter, flow capacity and pressure class • Calibration of the old conduit in order to ascertain whether the external size of the PE pipe to be inserted is correct • Breakdown of repair work into steps (a pipeline should be divided into straight sections, which will be refurbished. Basically, the points at which there is a change of direction, are the points of new pipe introduction) • Selection of points of insertion
8.2. Scope of installation work
•
I mplementation of point excavations for the introduction of CCTV cameras along with cutting out samples of the existing pipes • CCTV imaging of the pipeline route • Making of installation excavations • Drainage of excavations (if required) • Mechanical cleaning with steel pigs (in case of significant local build-ups on the pipe walls, which could prevent or significantly hinder the retraction of the PE pipeline) • Calibration of the pipeline • Manufacturing of the tubing head for the PE pipeline • Pulling of the PE tubing head with a several metre long PE pipeline section • Welding of pipes in sections corresponding to the length of the pipeline to be renewed between successive installation excavations
• Entrainment of the pipelines • Cutting the tubing head off after dragging a section of pipe between the excavations and heating up the loose steel flanged ends • Installation of fittings (tees and elbows) in trenches and connecting the dragged pipe sections on flanges • If required, making of pipeline fixed points by bracing support blocks • Pipeline hydraulic test • Injection of sealant into the inter-pipe space (if so recommended) • Backfilling of trenches • Pavement reconstruction
Pressure Systems Uponor Infra - manual | 4 7
8. Relining of pressure pipelines with PE pipes 8.3. Standard equipment for relining
• Uponor Infra welding machine (depending on DN of PE
pipe) Shelter - tent for protection welders against the weather • conditions and functioning both as stationary shelter and while performing the work Rollers to handle the pipes • Depending on soil conditions - the base plate for the • installation of the welding machine
• Backhoe • Tractor • Power generator • 6-ton crane (or 12-ton, depending on access to the trenches) Hoisting winch • Compressor • • Air hammers
8.4. Pipe connections Butt welding of PE pressure pipes (see the section ‘Pipe Connections’). Joints made in this way are
homogeneous, tight and have the same tear strength as the PE pipe.
8.5. Tubing heads for pipe entrainment PE pipe should be pulled by a specially built drive head, made of steel components (connecting the cable gripping bracket with PE pipe) connected by screwing with the end of
the PE pipe. Sample tubing heads for relining are shown in the pictures below.
After pulling a whole PE pipe section to the repaired pipe, the tubing head is cut off the pulled pipe between the start and end excavations with a short pipe section left and it can be reused by its welding to the next pipe
segment to be drawn. In the entrainment process, protect the PE pipe against contact with sharp edges of casing pipe and other sharp objects that might be present on the dragged pipe route.
8.6. Uponor Infra system and method of installation The type and size of the assembly chamber depends on the method of the PE pipe installation in the damaged conduit. PE pipes can be joined outside the trench into long sections, and when joined, the connected conduit can be pulled to the existing pipeline once or you can connect the pipe in
Uponor Infra system
WehoPipe
4 8 | Pressure Systems Uponor Infra - manual
the installation trench and after welding each pipe section (typically several meters long), you can drag the connected PE pipe into the damaged conduit. The work method depends on the field conditions.
Method of installation
• •
Pipe connection outside the assembly chamber (outside of the excavation Pipe connection inside the excavation (assembly chamber)
8. Relining of pressure pipelines with PE pipes 8.7. Pipe connection outside the excavation (assembly chamber)
• Inability to provide complete drainage / or withdrawal the
The criteria for selection the method of connecting pipes outside the trench: • The need for repair of long sections of sewer - large distance between the wells or lack thereof • Available space (land strip of appropriate length) for connecting pipes outside the trench
collector from service
• The rate of work - time and functional independence of the
welding process from the remaining preparatory and repair work
This process engineering involves pulling PE pipe having an outer diameter smaller than the effective inner diameter of the old pipeline including any constrictions, deformations and displacements.
System
Recommended length of inserted sections
WehoPipe
Depending on the condition of the existing pipeline and parameters of the inserted pipe (DN, SDR), it is possible to drag segments even above 1000 m long.
Usually, the assembly chamber is installed at the point of the pipeline route direction change. There, a start excavation is made, with a length dependent on the depth of the pipeline and the permissible bending radius of the pipe. From one start excavation, you can insert the connected pipeline in two
directions. When pulling long pipe sections welded on the surface, it is necessary to maintain the dimensions of excavations / or start chambers / that allow maintaining permissible bending radius of the pipeline.
Fig.8.7.1. Schematic profile of the start excavation for insertion long section of PE pipes to the old conduit R R
H
H 2
2H
PE PIPE
I' da Da
IG2 IG1 2IG2 Min. bending radius R for PE pipes
R= 30 DN
Temporary (for the time of installation)
R= 50 DN
Permanent (bending for more than 12h)
Pulling force for the PE pipelines The maximum force, with which the PE pipeline can be pulled without damaging it, calculated on the basis of the design stress sd (see the section ‘Nominal Pressure’)
For C= 1.25 ( acc. to ISO 12 126)
MRS 10,0 [MPa]
MRS 8,0 [MPa]
s
8.0
6.3
d
/ the above values refer to temp. 20 deg C/
Pressure Systems Uponor Infra - manual | 4 9
8. Relining of pressure pipelines with PE pipes Permissible pulling force: Fmax = sd A here: A – pipe wall cross section area.
Dimensions of start excavation
When determining the forces required to pull the pipe, the pipe weight and coefficient of friction of the pipe against the ground should be taken into consideration. F = q L (µ cos ϕ +/- sin ϕ) Where: q – unit weight of pipe [N/m] L – length of the pulled section µ – coeff. of friction (max.0.8) ϕ – pipeline angle of inclination
Dimensions of the start excavation are a function of pipeline depth and bending radius. Where: H – pipeline embedding depth R – bending radius
LG1 =
H (4 R – H)
If the pipe inserted can be raised to the height H above the land datum, the start excavation length can be reduced to the following values:
LG1 =
H (2 R – H)
Length of open trench:
L’=
Angle of inclination of the start excavation can be determined from the following relation:
tg ϕ = (H – Dn)/( LG – L’)
Dn(2R-Dn)
8.8. Pipe connection in the excavation (in the assembly chamber) In a situation where there is insufficient space to complete a long section on the outside of the excavation, the pipe should be connected inside the previously prepared assembly chamber. When doing this, be sure to: • Protect the excavation walls properly • Install the welding machine correctly (base plate) • Provide min operating dimensions of the chamber
(standard dimensions of the welded pipe sections: 12.5m, as well as dimensions of the machine and passages for welders) Protect the welding machine with a roof against the • weather both during welding and standstill • Drain the excavation continuously
For the diagram of pipe installation in a trench or assembly chamber, see the figure below:
L
Work parameters, such as: pulling force, type of equipment, etc., same as for work outside the excavation. L
5 0 | Pressure Systems Uponor Infra - manual
9. Handling and storage of PE pipes 9.1. Handling Loading and unloading of palletized pipes should be performed using a forklift with smooth forks. Pallets should be sound and strong enough as to not present a hazard when lifted. Pipes loaded individually must be transferred using soft lifting slings, such as polyester belts of adequate strength. Rods, hooks, metal chains, etc. may lead to damage in the event of improper handling of the pipes.
For the transport purposes, use flatbed trucks or special vehicles for transporting pipes. The platform should be free of any nails or other protruding elements. All sideboards should be flat and without any sharp edges. Pipes of the largest diameter of should be arranged at the bottom of the stack directly on the platform of the truck. Pipes stacked individually should be separated with wooden slats so that you can drag slings between them for unloading. In case of loading socket pipes, arrange the stack of pipes so that no direct contact between the sockets of individual pipes occurs. Tie the pipes firmly to prevent their shifting during transport. Pipes should not extend outside the truck platform to the length more than five times their nominal diameter and more than 2m (lower value is authoritative).
Never drop the pipes onto a storage location in an uncontrolled manner. Pipes should be moved into storage location with care. Dropping pipes can cause mechanical damage. Impact resistance of plastic pipes decreases with temperature drop, which requires special care when unloading at low temperatures.
m
For manual unloading, use polyester slings. Pipes unloaded manually may not pose any risk to workers with their weight. When unloading heavy pipes, use crane and suitable slings. During unloading, do not allow anyone to stay under the pipe or on the way of its move.
Pressure Systems Uponor Infra - manual | 5 1
9. Handling and storage of PE pipes 9.2. Storage Pipe store should be available for the personnel of e.g. quality control. The store should also be easy accessible for further deliveries. Do not store pipes near fire, heat sources or hazardous substances, such as: fuel, solvents, oils, varnishes, etc. Pipes should be stored in the same way as during transport, i.e. with wooden dividers. Wooden dividers should be flat and wide enough as not to cause deformation of the pipe. Pipes with the largest diameters must be stored at the bottom.
Pipes should not be stored directly on the ground. To do this, apply the pads analogous to those used between the pipes. The spacing between the pads should not exceed 2.5 m The substrate of the storage area should be flat and free of sharp objects. The height h of stored pipes should not exceed 3-4m.
5 2 | Pressure Systems Uponor Infra - manual
10. Chemical resistance tables for PE and PP Designations:
PE-HD - High Density Polyethylene PE-MD - Medium-Density Polyethylene PP - Polypropylene s.s. - saturated solution
1 – resistant 2 – partially resistant 3 – not resistant
The data below is derived from ISO TR 10358, ISO TR 7472 &, 7474
Compound:
Formula:
Content (%)
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
Aniline
C6H5-NH2
100
Ammonium nitrate
NH4NO3
s.s.
Magnesium nitrate
Mg(NO3)2
Copper nitrate
Cu(NO3)2
Nickel nitrate
Ni(NO3)2
Acetone
Furfuryl alcohol Alum
Potassium nitrate
KNO3
Mercuric nitrate
Hg(NO3)2
Sodium nitrate
NaNO3
Silver nitrate
AgNO3
Calcium nitrate
Ca(NO3)2
Ferric nitrate
Fe(NO3)3
Sodium nitrite
NaNO2
Benzene
C 6H 6
>10
>10
100
Petrol (gasoline) Sodium benzoate
C6H5COONa
Acetic anhydride
CH3CO-O-COCH3
Borax
100
Na2B4O7
Bromine (gas)
Br2
100
Bromine (liquid)
Br2
100
Potassium bromide
KBr
Sodium bromide
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
Pressure Systems Uponor Infra - manual | 5 3
10. Chemical resistance tables for PE and PP Compound:
Formula:
Content (%)
Potassium bromate
KBrO3
Butane
C4H10
100
Butanol
C4H9OH
100
Chlorine (solution)
Cl2
Chlorine (gas)
Cl2
Potassium chlorate
KClO3
Calcium chlorate
Ca(ClO3)10
Sodium chlorate
NaClO3
Ammonium chloride
NH4Cl
Barium chloride
BaCl2
Zinc chloride
ZnCl2
Tin chloride
SnCl2
Aluminium chloride
AlCl3
Magnesium chloride
MgCl2
Copper chloride
CuCl2
Nickel chloride
NiCl2
Mercuric chloride
HgCl2
Potassium chloride
100
s.s.
s.s.
KCl
Sodium chloride
NaCl
Thionyl chloride
SOCl2
Calcium chloride
CaCl2
Ferric chloride
FeCl3
Chloroform
ClcCH
100
Chloromethane
CH3Cl
100
Potassium chromate
K2CrO4
Chromic acid cleaning mixture Potassium cyanide
100
CrO3H2O
>10
KCN
>10
Mercuric cyanide
Hg(CN)2
Sodium cyanide
NaCN
Silver cyanide
AgCN
Hydrogen cyanide
HCN
10
C6H11OH
100
Cyklohexanone
C6H10O
100
Decaline
C10H18
100
(C6H10O5)n
>10
Cyklohexanol
Dextrin
5 4 | Pressure Systems Uponor Infra - 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 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
10. Chemical resistance tables for PE and PP Compound:
Formula:
Yeast
Content (%) >10
Potassium dichromate
K2CrO4
Dioxolan
C4H3O2
100
Carbon disulphide
CS2
100
Chlorine dioxide
ClO2
100
Sulphur dioxide
SO2
100
C2H5OH
40
C2H5-O-C2H5
100
Phenol
C6H5OH
>10
Fluorine
F2
100
Ammonium fluoride
NH4F
>10
Aluminium fluoride
AlF3
s.s.
Potassium fluoride
KF
Ethanol Diethyl ether
Sodium fluoride
NaF
Formaldehyde
HCHO
40
Octyl phthalate
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
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
Pressure Systems Uponor Infra - manual | 5 5
10. Chemical resistance tables for PE and PP Compound: Gluconic acid
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
Phosphoric acid Picric acid
(NO2)3C6
Propionic acid
CH3CH2COOH
50
Propionic acid
CH3CH2COOH
100
Salicylic acid
C6H4OHCOOH
Sulphurous 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
Concentρ.
Oxalic acid Tolyl acid Tartaric acid
(COOH)2 C6H3COOH COOH(CHOH)2COOH
using. conc.
Molasses Methanol Milk
>10
CH3OH
100
(Krowie i owcze)
100
(NH2)2CH
>10
Urine Urea Potassium perchlorate
KClO4
Potassium permanganate
KMnO4
20
Potassium persulphate
K2S2O8
20
Vinegar Amyl acetate
see vinegar CH3COO(CH2)4CH3
5 6 | Pressure Systems Uponor Infra - manual
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
10. Chemical resistance tables for PE and PP Compound:
Formula:
Content (%)
Ethyl acetate
CH3COOC2H5
100
Silver acetate
CH3COOAg
Oils and greases Mineral oils Sodium orthophosphate Potassium orthophosphate Ozone
Na3PO4 K3PO4 O3
100
Perchlorate
H2O2
30
Perchlorate
H2O2
90
C 5H 5N
100
Potassium hypochlorite
KClO
>10
Potassium hypochlorite
NaClO
5
Ca(ClO)2 4H2O
<10
Hg
100
(NH4)2SO4
s.s.
Pyridine Beer
Calcium hypochlorite 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
Ferric sulphate Ammonium sulphide
s.s.
Fe2(SO4)3 (NH4)2S
>10
Barium sulphide
BaS
>10
Potassium sulphide
K2S
>10
Calcium sulphide
CaS
<10
Sodium sulphide
Na2SO3
Hydrogen sulphide (gas) Tannin Carbon tetrachloride Oxygen Zinc oxide
H 2S
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
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
Pressure Systems Uponor Infra - manual | 5 7
10. Chemical resistance tables for PE and PP Compound:
Formula:
Content (%)
CO
100
C6H5-CH3
100
Antimony trichloride
SbCl3
90
Phosphorus trichloride
PCl3
100
Trichloroetylhene
Cl2C=CHCl
100
Triethanolamine
N(CH2CH2OH)3
>10
Sulphur trioxide
SO3
100
Calcium oxide 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
H 2O
Aqua regia
HCl + HNO3
3/1
Hydrogen
H2
100
Sodium hydrogen phosphate
Na2HPO4
Potassium bisulphate
KHSO4
Potassium bisulphite
KHSO3
>10
Sodium bisulphite
NaHSO3
>10
Barium hydroxide
Ba(OH)3
Magnesium hydroxide
Mg(OH)2
Potassium bicarbonate
KHCO3
Sodium hydroxide
NaOH
>10
Sodium hydroxide
NaOH
40
Potassium hydroxide
KOH
10
Potassium hydroxide
KOH
>10
Calcium hydroxide
Ca(OH)2
Sodium bicarbonate
NaHCO3 norm. conc.
Photographic developer Potassium ferricyanide
K3Fe(CN)6
Potassium ferricyanide
K2Fe(CN)6
Sodium ferricyanide
N3Fe(CN)6
Sodium ferrocyanide
N4Fe(CN)6
5 8 | Pressure Systems Uponor Infra - 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 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
Sales Department ul. Przemysล owa 5 97-410 Kleszczรณw POLAND T +48 44 731 34 00 0 | 44 Pressure Uponor Infra - manual F6+48 731 34Systems 10
www.uponor.pl/infra
04/2020/1966
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