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Safety shut-off valve RMG 703 / RMG 704

Technical product information

703.00 704.00 edition 09/2001

Safety and reliability in gas pressure control


Safety shut-off valve RMG 703 / RMG 704 Appkication • Main safety device in gas pressure control systems for municipal supply, industrial plants and individual consumers • Also for low-load rails in larger gas pressure control systems • Suitable for natural gas and all non-aggressive gas media

Features • RMG 703: Two independent safety shut-off valves in a single main valve body (Tandem SAV) • RMG 704: single SAV • compact design, simple construction • Easy to maintain through exchangeable functional assemblies (plug-in system) • Optionally fittted with control devices K 1a, K 2a, K 16, K17, K 18 • Pressure compensation through ball valve or push button valve RMG 913

1. Technical specifications max. operating pressure pmax

up to 100 bar (depending on connection type)

valve seat diameter

25 mm

connection type

inlet/outlet: solderless pipe connections to DIN 2353, PN 100 for external pipe diameter 10, 12, 16, 18, 22, 25, 28, 38 and 42 mm Flanges to DIN PN 25 and PN 40, ANSI 300 and 600 with taper pieces size DN 25, 40, and 50

material

main valve body control unit housing internal components diaphragms, seals

temperature range

-20 ˚C to + 60 ˚C

response time

0.1 ... 0.3 sec

accessories

- electric relase on current supply - electric position indication - manual release - screw-in connections for combination with RMG 200 (E 42) and RMG 201 (E 18)

function and strength

DIN 3381

DIN DVGW reg. no.

RMG 703: NG-4303AN0197, RMG 704: NG-4303AN0196

2

wrought aluminium alloy or steel wrought aluminium alloy or steel stainless steel, brass, steel NBR (rubbery plastic)


Safety shut-off valve RMG 703 / RMG 704 Setting range of the SAV control units control unit

setpoint spring

overpressure underpressure response smallest difference smallest difference pressure between response between response category** setting pressure and normal setting pressure and normal range operating pressure * range operating pressure * Who (bar) ∆p (bar) Whu (bar) ∆p (bar) AG

no.

colour

wire dia. in mm

1 2 3 4 5 6 7

yellow light red dark red white light blue wjhite black

2.5 3.2 3.6 4.75 1.1 1.2 1.4

0.05 ... 0.100 0.1 ... 0.250 0.2 ... 0.500 0.4 ... 1.500

1 2 3 4 5

light red dark red white light blue black

3.2 3.6 4.75 1.1 1.4

0.4 ... 0.8 0.6 ... 1.6 1.5 ... 4.5

K16

0 1 2 3 4

blue black grey brown red

3.2 4.5 5.0 6.3 7.0

0.8 ... 1.5 1 ... 5 2 ... 10 5 ... 20 10 ... 40

K17

2 3 4

grey brown red

5.0 6.3 7.0

K18

1

K1a

K2a

9.0

0.030 0.050 0.100 0.250 0.010 ... 0.015 0.014 ... 0.040 0.035 ... 0.120

0.050 0.080

10 / 5 10 / 5 5 / 2.5 15 / 5 5

0.100 0.200 0.300 0.060 ... 0.150 0.120 ... 0.400 0.1 0.2 0.4 0.8 1.2

2.5 2.5 / 1 1 1 1 2 ... 10 5 ... 20 10 ... 40

20 ... 90

0.012 0.030 0.060

10 / 5 10 / 5 5 / 2.5 5 / 2.5 15 15 / 5 5

0.4 0.8 1.2

1,5

5 5 5 1

*) Please note: Where control units are being used simultaneously for upper and lower response pressure, the difference between the two setpoint values pso and psu must be at least 10% greater thant he sum of the values ∆po and ∆pu. **) The higher AG category applies to the first half, the lower AG category to the second half of the setting range.

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Safety shut-off valve RMG 703 / RMG 704 2. Dimensions 2.1 Dimensions RMG 703

For console mounting 4 threaded holes M8 x 18 deep hole interval 75 mm

115 115

A

B construction length C optional as per connection type C=2x A C=2x B C=A+B

pipe connection A* designation E 10 E 12 E 16 E 18 E 22 E 25 E 28 E 38 E 42

pipe size 10 x 1,5 12 x 1,5 16 x 1,5 18 x 1,5 22 x 2 25 x 3 28 x 2 38 x 5 42 x 3

flange connection B

A in mm 168 164 174 168 170 184 171 178 163

B in mm pressure DN 25 DN 40 DN 50 rating PN 25 & PN 40

236

236

236

ANSI 300 261 RF/RJ

260

266

ANSI 600 261 RF/RJ

266

266

* Solderless pipe connection with cutting ring to DIN 2353

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Safety shut-off valve RMG 703 / RMG 704 design with control unit K 1a, K 2a

design with control unit K 16, K 17, K 18

E

F K 18

vent line

L vent line

K

J measuring line connection

I H L

total dimension when complete N

total height M

I H

vent and relief line

K 16

total height M

G mesuring line connection

total dimension when complete N

K 17

K

F vent and relief line

E SAV design with control unit

E

F

G

H

I

J

K 1a, K 2a K 16, K 17 K 18

215 215 260

90 90 90

100 -

40 40 40

90 90 90

215 105 430 460 110 265 105 490 520 110 430 105 860 890

device dimensions in mm K

L

M

N

connection lines measuring, vent, and relief lines

screw connections* for pipe 12 x 1.5

* Solderless connections with cutting ring to DIN 2353

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Safety shut-off valve RMG 703 / RMG 704 2.2 Dimensions RMG 704

67,5

For console mounting 4 threaded holes M8 x 18 deep hole interval 75 mm

67,5

B

A

construction length C optional C= 2xA C= 2xB C = A +B

pipe connection A* designation E 10 E 12 E 16 E 18 E 22 E 25 E 28 E 38 E 42

pipe size 10 x 1,5 12 x 1,5 16 x 1,5 18 x 1,5 22 x 2 25 x 3 28 x 2 38 x 5 42 x 3

flange connection B A in mm 120 116 126 120 122 136 123 130 115

pressure B in mm rating DN 25 DN 40 DN 50 PN 25 & PN 40

188

188

188

ANSI 300 RF/RJ

213

212

218

ANSI 600 RF/RJ

213

218

218

* Solderless pipe connections with cutting ring to DIN 2353

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Safety shut-off valve RMG 703 / RMG 704 design with control unit K1 or K 2a

design with control unit K16, K17 or K 18

K 18 size when complete M

vent line

K

G measuring line connection

vent and relief line

K 17 K 16

K

measuring line connection

I H

size when complete M

E

J

L

I H L

F F E

SAV design with control unit

E

K 1a, K 2a K 16, K 17 K 18

215 90 215 90 260 90

device dimensions in mm F

G

H

I

J

K

L

M

100 -

40 40 40

90 90 90

215 105 230 110 245 105 265 110 430 105 445

connection lines measuring, vent, and relief lines

connections* for pipe 12 x 1.5

* Solderless pipe connections with cutting ring to DIN 2353

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Safety shut-off valve RMG 703 / RMG 704 3. Design and operation The safety shut-off valves RMG 703/704 are designed to automatically shut off the flow in gas pressure control systems when the pressure in the system to be protected reaches an upper (overpressure) or lower (underpressure) response pressure value. The double safety shut-off device RMG 703 consists of two independently operating functional assemblies. This fulfils the requirements of DVGW work sheet 491 that gas pressure control systems with a pressure relation p emax - p azul > 16 bar and pemax/pazul > 1,6 must have two independently operating SAVs installed. The design of the safety shut-off valve RMG 704 is similar to the SAV RMG 703, except that it is designed as single SAV. The safety shut-off valves RMG 703/704 consist mainly of the components main valve body, switching gear, control unit and bypass valve. Both devices are constructed particularly maintenance-friendly. Each functional assembly can be removed by unscrewing whilst the main valve body remains in the line.

Operation with control unit RMG 673 (K 1a, K 2a) The pressure to be monitored is applied to the compensating diaphragm in the control unit and compared with the reference values provided by the setpoint spring (response pressure setpoint). Upon reaching the response pressure setpoint by way of overpressure or underpressure, the compensating diaphragm and the engaging mechanism of the switchgear are in the disengaged position and release the locking mechanism. The spring of the actuator then closes the shut-off valve. Note: Opening the main valve and locking the valve stem is only possible by hand after the outlet pressure at the measuring location is below (after release pmax) or above (after release pmin- ) the re-engagement difference.

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Safety shut-off valve RMG 703 / RMG 704

control unit

setpoint adjuster

setpoint spring - for underpressure - for overpressure switch valve RMG 919 connection vent line

compensating diaphragm

ball engaging mechanism

measuring line connection

main valve body main valve electric remote indicator optical SAV position indicator

control unit

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Safety shut-off valve RMG 703 / RMG 704 Operation with control unit RMG 670/671 (K16, K17, K 18) The pressure of the system to be protected is directed via a measuring line on top of the sensitive double diaphragm system and compared with the reference values given by the setpoint adjustment screw (setpoint spring force). Under normal operating conditions the amplifier valve remains closed. Should the upper response pressure for RMG 670 or the lower response pressure for RMG 671 be reached, the amplifier valve opens. Gas will flow from the system to be monitored into the pressure/force transducer. The piston in the pressure/force transducer moves and actuates the switchgear of the SAV via the piston rod, thus closing the safety shut-off valve. Once the cause for the release of the SAV has been removed and the monitored pressure is again below the preset setpoint (for overpressure release with RMG 670) or above (for underpressure release with RMG 671), the amplifier valve closes. The pressure at the piston of the main valve dissipates via the throttle integrated in the control unit, and the safety shut-off valve can be opened again. The control unit RMG 670 also meets the requirement that the safety shut-off valve must release when the measuring diaphragm breaks. The monitored outlet pressure is present at the upper side of the double diaphragm system. Should this upper diaphragm of the double diaphragm system be faulty, the outlet pressure will be directed directly to the pressure/force transducer and cause the SAV to release.

SAV RMG 704 with switch gear

vent line

from control unit switch gear

pressure/force transducer

main valve body

electric remote indicator

optical SAV position indicator

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main valve


Safety shut-off valve RMG 703 / RMG 704 control unit RMG 670-K16

control unit RMG 670-K17

for upper setting range

for lower setting range setpoint adjuster setpoint spring vent/ relief line throttle

outlet to pressure/force transducer

outlet to pressure/force transducer

double diaphragm system amplifier valve inlet (measuring line)

control unit RMG 670-K18 for upper setting range with metal harmonica measuring unit setpoint adjuster setpoint spring throttle vent/ relief line

amplifier valve inlet (measuring line)

outlet to pressure/force transducer

metal harmonica measuring unit

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Safety shut-off valve RMG 703 / RMG 704 Diagram for determining the pressure drop and flow rate for RMG 703

0 10

40

30

16

re

0,5

10

5

3

pe

1

in

0,7

2

ba

r

1,0

pr

es

su

0,4

pressure drop ∆ p in bar

inl

et

0,3 0,2

0,1

s

m/ 50 = ax s vm 0 m/ 4 = s v m/ 30 = v s m/ 20 = v

0,07 0,05 0,04 0,03 0,02

Weg 2

Weg 1 0,01

40

50

70

100

200

300

flow

400

500

700

1000

2000

3000

3

q n in m /h

The natural gas flow should be used to determine the pressure drop. When using other gas media, the equivalent of the natural gas flow should be used in calculations conversion factor f = q n Erdgas =

q n Gas f

in m 3 /h

standard gas (city gas) air nitrogen oxygen hydrogen

√ 0,83/ρn gas 1.23 0.80 0.81 0.76 3.04

example 1 operating data: p e = 16 bar q n = 800 m 3 /h (city gas)

example 2 operating data: p e = 16 bar q n = 800 m 3 /h (city gas)

calculation of pressure drop ∆ p (method 1) equivalent natural gas flow

calculation of flow rate v (method 2) flow rate value of gas medium q n = 800 m 3 /h p e = 16 bar

q n Erdgas = q n Gas 800 1,23 f

= 650 m3 /h

result (method 1): pressure drop ∆ p ≈ 0.27 bar

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result (method 2): flow rate v ≈ 27 m/s

4000


Safety shut-off valve RMG 703 / RMG 704 Diagram for determining the pressure drop and flow rate for RMG 704

0 10

40

et pr es su re

0,5

30

16

10

5

3

pe

1

in

0,7

2

ba r

1,0

0,4

pressure drop ∆ p in bar

inl

0,3

0,2

0,1

0,07

ax vm /s 0m 4 v = m/s 30 v=

0,05 0,04

0,03

0,02

2 v=

0m

0 =5

m/

s

/s Weg 1

Weg 2

0,01

50

100

200

300

flow

example 1 operating data:p e = 10 bar

calculation of pressure drop ∆ p (method 2) equivalent natural gas flow

result (method 2):

500

1000

2000

3000

5000

3

q n in m /h

example 2 operating data: p e = 10 bar

q n = 500 m 3 /h (nitrogen)

q n Erdgas = q n Gas 500 0,81 f

400

3

q n = 500 m /h (nitrogen) caculation of flow rate v (method 1) flow-through value of gas medium qn = 500 m / h 3 pe = 10 bar

= 617 m 3 /h

pressure drop

result (method 1): flow rate v ≈ 26 m/s ∆ p ≈ 0,2 bar

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Safety shut-off valve RMG 703 / RMG 704

14


Safety shut-off valve RMG 703 / RMG 704

special design (to be specified)

remote transfer

accessories

SAV control unit

type

(example)

outlet connection

RMG 703 - E 18 / DN 25 - K 16 - HA - E1 - F - So inlet connection

4. Device designation

device type tandem SAV single SAV

703 703 704 704

inlet and outlet connections pipe connection

flange connection

E 10 E 12 E 16 E 18 E 22 E 25 E 28 E 38 E 42 pzul depending on pressure rating PN 25 and PN 40 ANS 300 RF/RJ ANSI 600 RF/RJ

DN 25 DN 40 DN 50

SAV setting range upper setting range lower setting range W ho [bar| W hu [bar| 0.05 ... 1.5 0.4 ... 4.5 0.8 ... 40

0.01 ... 0.12 0.6 ... 0.4

0.8 ... 40 20 ... 90

2.0 ... 40 2.0 ... 40

K 1a K 2a K 16 K 17 K 16/K 17 K 18

accessories electric release on current supply manual release electric position indication special design (to be specified)

E1 HA F So

Note: For tandem safety shut-off valve RMG 703 note that both SAV main valves are normally fitted with the same control units and accessories. Variations available as special design.

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We supply products for gas pressure control: RMG REGEL + MESSTECHNIK GMBH Osterholzstrasse 45, D-34123 Kassel, Deutschland Telephone (++49) 561 5007-0 • Fax (++44) 561 5007-107 Gas pressure regulators and safety devices

RMG-GASELAN Regel + Meßtechnik GmbH Julius-Pintsch-Ring 3, D-15517 Fürstenwalde, Deutschland Telephone (++49) 3361 356-60 • Fax (++49) 3361 356-836 Gas pressure regulator technology, rotary displacement meters, and complete systems

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 regulator technology, subterrestrian compact systems, complete stations

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 pressure regulators and safety devices

Other companies in the RMG Group: RMG Messtechnik GmbH Otto-Hahn-Strasse 5, D-35510 Butzbach, Deutschland Telephone (++49) 6033 897-0 • Fax (++49) 6033 897-130 Turbine meters, vortex meters, and electronic translation devices

Karl Wieser GmbH Anzinger Strasse 14, D-85560 Ebersberg, Deutschland Telephone (++49) 8092 2097-0 • Fax (++49) 08092 2097-10

Beindersheim branch Heinrich-Lanz-Strasse 9, D-67259 Beindersheim/Pfalz, Deutschland Telephone (++49) 6233 3762-0 • Fax (++49) 6233 3762-40 Devices for capturing, transmitting and evaluation measuring data

WÄGA Wärme-Gastechnik GmbH Osterholzstrasse 45, D-34123 Kassel, Deutschland Telephone (++49) 561 5007-0 • Fax (++49) 561 5007-207 Gas pressure regulating systems, flow meters, supply optimisation

The RMG Group on the web: http://www.rmg.de

Your competent partner

Comprehensive gas supply services

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