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Safety Relief Valve RMG 850

General Description

850.00 Edition 09/2001

Serving the Gas Industry - WORLDWIDE

Safety Relief Valve RMG 850 Application • for offtake stations in gas transmission systems, for gas supply to industrial and power plants • suitable for full capacity relief • for natural gas and all non-corrosive gaseous media

Features • • • • • •

in-line flow can be installed in any position safe operation high response accuracy quick reaction can be provided with a noise reducing outlet duct module RMG 512 as an optional feature

1. Technical Data max. service pressure pmax

100 bar max. permissible service pressure

adjusting ranges with measuring unit RMG 670

2 to

closing pressure

5 bar

40 bar

ps = 0.5 bar

2 to 10 bar

40 bar

ps = 0.6 bar

5 to 20 bar

40 bar

ps = 1.0 bar

10 to 40 bar

50 bar

ps = 1.5 bar

20 to 90 bar*

100 bar

ps = 2.0 bar

*) with metal harmonica type measuring unit sizes/flow rate coefficients

DN 25

KG-value

500 m3/h

(KG-value für natural gas, =0,83 kg/m3)

DN 50

KG-value

2000 m3/h

DN 80

KG-value

5100 m3/h

DN 100

KG-value

8000 m3/h

2

Valve seat diameter

equals nominal width of inlet connection

Connections

flanged to DIN PN 25, PN 40 and to ANSI 300, ANSI 600

Materials

main valve body

cast steel, steel

internal parts

steel, aluminium, brass

measuring unit

aluminium alloy, steel

diaphragm

rubber-like plastic material (NBR, FPM)

sealings

rubber-like plastic material

Temperature range

-15°C to +60°C

Function and strength

acc. to DIN 3381

DIN-DVGW-registration No.

DN 25

DN 50

DN 80

DN 100

89.01e042

89.02e042

89.03e042

89.04e042

Safety Relief Valve RMG 850 2. Dimensions Fig. 2: RMG 850 with measuring unit RMG 670 and noise reducing outlet duct

A

C

B

L

L

D

Fig. 1: Main valve RMG 850 without measuring unit

number of tapped holes N

Dimensions in mm Size DN inlet outlet 25

50 80 100

25 100* 150* 50 150* 200* 80 250* 100 300*

PN 25 + PN 40 L A B C N 200 360 360 270 422 422 310 512 370 548

M12 16

21

4

M16 20

25

4

M16 20

25

8

M20 26

32

8

ANSI 300 RF L A B C 197 359 359 267 421 421 318 516 368 548

N

M16 20

25

4

M16 20

25

8

M20 26

32

8

M20 26

32

8

ANSI 300 RTJ L A B C N 210 365 365 283 429 429 333 523 384 555

M16 20

25

4

M16 20

25

8

M20 26

32

8

M20 26

32

8

ANSI 600 RF L A B C 210 365 365 286 430 430 337 525 394 560

N

M16 20

25

4

M16 20

25

8

M20 26

32

8

M24 31

38

8

ANSI 600 RTJ L A B C N D 210 365 365 286 430 430 337 525 394 560

M16 20

25

4

M16 20

25

8

M20 26

32

8

M24 31

38

8

75 84 84 92 100 103

* with noise reducing outlet duct (outlet flanged to ANSI 600 RF only) Connections Inlet size DN 25 50 80 100

measuring impulse line pipe thread 10 x 1,5

discharge line pipe thread

vent line pipe

12 x 1,5

min.

12 x 1,5

thread

M14 x 1,5 M14 x 1,5

M14 x 1,5

3

Safety Relief Valve RMG 850 3. Design and Operation The safety relief valve RMG 850 was designed to open automatically, as soon as the pressure of the system to be protected and monitored comes up to the pre-adjusted setpoint.

The safety relief valve consists of a main valve and a measuring unit. The main valve consists of the control element and the piston assembly as a complete modular unit. A filter is provided upstream to protect the measuring unit and the bleed bore from contamination.

The control element consists of a movable sleeve and a valve cone fixed into the body. The advantage of this design is that the gas passes straight through without any diversion, thus exerting forces in axial direction only. The movable sleeve is - to a large extent - pressure compensated, so that changes of service pressure does not tell upon the response precision of the valve.

The piston assembly has a fixed connection to the valve sleeve of the control element. The chambers above and below the piston are interconnected through a bleed bore so that in the basic position both chambers are exposed to the same pressure and the valve is kept closed by the force of the closing spring.

The high response accuracy of the safety relief valve is due to the fact that the measuring unit is equipped with a sensitive double diaphragm system with the amplifying valve placed between the diaphragms.

The pressure to be monitored is fed to the lower side of the double diaphragm system through the measuring impulse line, and compared to the pressure given by the force of the pre-adjusted setpoint spring. Under normal service conditions the amplifying valve is closed; the pressure prevailing in the upper and lower diaphragm chambers are equal.

If the pressure to be controlled reaches the setpoint pre-adjusted at the measuring unit, the valve in the double diaphragm system will open and thus reduce the pressure in the piston chamber below the piston. The pressure of the outlet system exerted on the upper side of the piston will move the sleeve against the force of the closing spring in opening direction.

If the pressure to be monitored falls below the pre-adjusted setpoint the amplifying valve will close again to restore the pressure in the chamber below the diaphragm. Upon pressure balance prevailing in the lower and upper piston chambers the safety relief valve will automatically close tight again.

Attention: When pressurizing the system (filling the outlet line with gas) the start-up vlave should be held open to avoid incontrolled blow-off of the main valve. When the outlet pressure has reached a stable level, let go of the contact valve again.

4

Safety Relief Valve RMG 850

vent line control element

setpoint adjuster

main valve valve cone valve sleeve

setpoint spring

manual start-up valve

bleed bore vent line

double diaphragm system

piston assembly closing spring

amplifying valve

filter RMG 905

measuring line

outlet pressure atmosphere

5

Safety Relief Valve RMG 850 special feature

measuring unit

DN outlet

DN inlet

RMG 512 - 50 / 200 - 670 - So type

4. Type Description (Example)

size DN (main valve without noise reducing outlet duct) inlet

outlet

25 50 80 100

25 50 80 100

size DN (main valve with noise reducing outlet duct) inlet

outlet

25 25 50 50 80 100

100 150 150 200 250 300

measuring unit RMG 670 special feature (to be described in detail)

7

We supply you with products for gas pressure regulation: RMG REGEL + MESSTECHNIK GMBH Osterholzstrasse 45, D-34123 Kassel, Germany Telephone (++49) 561 5007-0 • Fax (++49) 561 5007-107 gas pressure regulators and safety devices

RMG-GASELAN Regel + Meßtechnik GmbH Julius-Pintsch-Ring 3, D-15517 Fürstenwalde, Germany Telephone (++49) 3361 356-60 • Fax (++49) 3361 356-836 gas pressure regulating equipment, displacement meters, complete stations

Bryan Donkin RMG Gas Controls Ltd. Enterprise Drive, Holmewood, Chesterfield S42 5UZ, England Telephone (++44) 1246 501-501 • Fax (++44) 1246 501-500 gas pressure regulating equipment, below ground gas control modules

Bryan Donkin RMG Co. of Canada Ltd. 50 Clarke Street South, Woodstock, Ontario N4S 7Y5, Canada Telephone (++1) 519 5398531 • Fax (++1) 519 5373339 domestic regulators and safety devices

The other RMG Companies: RMG Messtechnik GmbH Otto-Hahn-Strasse 5, D-35510 Butzbach, Germany Telephone (++49) 6033 897-0 • Fax (++49) 6033 897-130 turbine meters, vortex meters, correctors, flow computers, odorizers

Karl Wieser GmbH Anzinger Strasse 14, D-85560 Ebersberg, Germany Telephone (++49) 8092 2097-0 • Fax (++49) 8092 2097-10

Betriebsstelle Beindersheim Heinrich-Lanz-Strasse 9, D-67259 Beindersheim/Pfalz, Germany Telephone (++49) 6233 3762-0 • Fax (++49) 6233 3762-40 data logging, monitor systems, danger alarm systems

WÄGA Wärme-Gastechnik GmbH Osterholzstrasse 45, D-34123 Kassel, Germany Telephone (++49) 561 5007-0 • Fax (++49) 561 5007-207 design and assembly of gas pressure regulating and metering stations

The RMG Group of Companies on the internet: http://www.rmg.de

Serving the Gas Industry - WORLDWIDE

We reserve the right for technical changes