RMG 720 Guida
Operation and Maintenance,
Spare Parts edition 08/1991
Serving the Gas Industry - WORLDWIDE
720.20
Safety Shut-Off Valve
RMG 720
720.20 S.02
720.20 S.3
Our leaflet 720.00 gives full information with technical data, different versions, and dimensions of the safety shut-off
valve (SAV) RMG 720.
Our brochure "General Operating Instructions for Gas Pressure Regulators and Safety Devices" will be useful to fit
the valve into the line, put it into service and find faults that might disturb its operation.
The construction, set-up, supervision and maintenance of gas pressure regulating stations are subject to special
national technical rules which should be strictly observed, for example those given by the German DVGW Work-
sheets G 490, G 491, and G 495.
The frequency of periodical maintenance to be foreseen for the safety shut-off valve RMG 720 should be determined
according to the prevailing service conditions and the type and composition of the gaseous medium. We, therefore,
obstain from imposing any fixed intervals and would rather refer you to the recommendations given by the DVGW
Worksheet G 495 on "Gas Pressure Regulating Stations and Metering Stations for High Gas Volumes - Supervision
and Maintenance".
For maintenance all parts are to be cleaned and subjected to a thorough visual inspection. A visual inspection should
not be omitted when the course of operation or performance tests have shown lack of response accuracy.
Particular care should be given to the checking of sealings and diaphragms, as well as all carrying and movable parts.
Damaged parts should be replaced by new ones.
The item numbers referred to in the maintenance instructions are identical with those of the spare parts drawings and
spare parts lists.
We recommend to keep all parts that are specially marked (*) in the spare parts lists in stock for prompt maintenance
availability.
2. Special operating instructions
• Opening the safety shut-off valve (SAV)
The SAV is provided with underpressure shut-off release. Re-engagement is possible only after the pressure pre-
vailing at the measuring point comes up to the service pressure p . The pressure compensation necessary for re-
opening is automatically effected by the pressure compensating valve integrated in the valve plate.
Measuring units K 1a, K 2a
(for incorporation into RMG 720 DN 25, and into RMG 300, RMG 330, RMG 332 as well as RMG 402)
Screw out locking cap (1), turn upside-down, screw
it on to valve stem and turn slowly towards body:
The pressure compensation will respond.
Pull locking cap until stop and let it go back
smoothly: The SAV is open and will re-engage.
In order to ensure perfectly reliable SAV-release
performance after re-opening, it is
to screw the locking cap back into its normal
position
a
ATTENTION
indispensable
1. General Remarks
locking cap (1)
valve stem (40, 53, 59)
720.20 S.04
Measuring units K4, K5, K6
(for incorporation into RMG 720, DN 50 to DN 100, and into RMG 330, RMG 332, RMG 408)
Press valve stem towards main body; cap (130) and
a suitable tool (screw driver) can be used as a lever.
Exert pressure SLOWLY and wait until pressure
compensation is effected. Press valve stem
through until stop and let it go back smoothly:
The SAV is open and will re-engage.
When using the tripping valve RMG 919-3 instead
of a breathing line, make sure to screw out the
locking screw (100) prior to re-engagement
operation.
Measuring units K4, K5, K6
(for incorporation into RMG 402)
Screw out locking cap, turn it round, screw it on
to valve stem and turn slowly towards body;
the pressure compensation valve will respond.
Pull locking cap until stop and let it go back
smoothly: The SAV is open and will re-
engage.
In order to ensure perfectly reliable SAV-release
performance after re-opening, it is indispensable
to screw the locking cap (201) back into its normal
position.
• Tripping tests
In order to avoid the risk of mechanical damages tripping tests should be effected only after the measuring unit will
have been mounted into the main valve body.
ATTENTION
ATTENTION
valve stem (207)
locking cap (201)
locking screw (100)
valve stem (156)
cap (130)
ATTENTION
tripping valve
RMG 919
tripping valve
RMG 919
Tripping tests with the measuring units K4, K5, K6 incorporated in the gas pressure regulator
RMG 402 must not be made as long as the locking cap (201) is screwed on to the valve stem
(207).
720.20 S.05
3. Special maintenance instructions
• Measuring units
Trip the SAV before you remove it from the body. SAV valves provided with underpressure release (standard version)
will close automatically.
ATTENTION
Prior to dismantling the tripping mechanism, the valve plate and the valve stem (40, 53, 59, 156, 207) of a measuring
unit released by underpressure should be moved back to reach at least its re-engagement position.
In view of the necessity of a new zero-adjustment by means of the shim (138, 234) an exchange of the measuring units
K5 for K4 or K4 for K5 or K6 cannot be made at site.
• Valve stem (40, 53, 59, 156, 207)
It is important that the valve stem can be moved easily and smoothly. Should any faults or damages of material (e.g.
ridges or flaws) be detected at the valve stem shoulder, the valve stem has to be replaced by a new one.
When fitting an new (two-piece) valve stem into the measuring units K4, K5, K6 of the series produced up to 1989,
make sure that a new guide sleeve (139, 243) and a new closing spring (119, 242) are mounted together with the
valve stem. The new version does not provide for a pressure relief ball mechanism.
Before inserting the valve stem (156, 207) into the guide sleeve (139, 242) pull the pressure relief balls (former
version) apart by applying the special assembly bolt W4 from above.
• Spring retainer (24, 103, 204)
The contact surfaces between spring retainer and diaphragm plate (26) and between switch bush (8), spring retainer
and guide sleeve (104, 206) should be kept free from grease.
• Relieving springs
For maintenance of measuring units K4, K5, K6 delivered before July 1986 make sure to fit new relieving springs
stock no. 10 008 640.
• Valve plate (155, 222)
For inserting the O-ring (124, 220) into the groove of the valve plate proceed as follows:
- grease the O-ring and put it on the groove; apply an equal pressure by hand on several points around its circum-
ference for even insertion.
- press the O-ring fully into the groove.
• Shim (138, 234)
The shim serves to adjust the tripping device to its exact zero position. After any replacement of the diaphragm, the
shim must be re-integrated unchanged.
720.20 S.06
• Switch bush (8, 26, 137, 232)
If the bush shows any signs of defects (e.g. flaw in material), replace it by a new one.
• Torque
Tighten the screws (9, 148) and nuts (51, 58, 113, 213) by torque wrench to the torque levels of the table below:
• Lubricants
screws and nuts
item no.
9
51
58
113, 213
148
torque figues M in Nm
SAV RMG 720
size DN
25 50 80 100
sub-unit for incorporation
into RMG 300, 330, 332
size DN
25 50 80 100
sub-unit for incorporation
into RMG 402, 408
inlet size DN
25 50 80 100
12
10
20
10
20
10
20
12
12
12
10
40
12
12
12
10
40
10
40
10
40
12
12
12
10
25
10
40
10
40
A
Lubricant
silicone grease
stock no. 00 027 079 (box)
stock no. 00 027 081 (tube)
fitting paste
stock no. 00 027 091
pressure gun grease
stock no. 00 027 058
application (grease parts slightly)
all O-rings
diaphragm reinforcement (10, 140, 211)
valve stem guide range (40, 53, 59, 156, 207)
switch balls and bushes (14, 18, 52, 63, 106, 137, 208, 232)
setpoint adjusting screw (4, 102, 202)
screwed pipe connections (28, 37, 49, 143, 168, 172, 231, 236, 249)
fastening bolts and screws (9, 17, 45, 127, 148)
720.20 S.07
W7
W6
(for former models)
RMG 720
RMG 300
RMG 330
RMG 332
RMG 402
RMG 720
RMG 330
RMG 332
RMG 402
RMG 408
for all models
RMG stock no.
• Tools for assembly and adjustment
type
RMG 720
RMG 300
RMG 330
RMG 332
RMG 402
RMG 330
RMG 332
RMG 402
RMG 720
RMG 330
RMG 332
RMG 402
RMG 408
DN 25
DN 25
DN 25 and DN 50
DN 25 and DN 50
DN 25
DN 80 and DN 100
DN 80 and DN 100
DN 50 to DN 100
DN 50 to DN 100
DN 80 and DN 100
DN 80 and DN 100
DN 50 to DN 100
DN 50 to DN 100
size for item no. tool no. description
tool for assembly
13 W1 pliers A 19 DIN 5254 00 026 531
20, 121,
219, 308 W2 pliers D 19 DIN 5256 00 026 532
110,
238,
322 W5
twin-dowel key
10 008 582
DN 25
DN 25
DN 25 and DN 50
DN 25 and DN 50
DN 25
DN 50 to DN 100
DN 80 and DN 100
DN 80 and DN 100
DN 50 to DN 100
DN 50 to DN 100
4W7
102,
202 W7
tool for adjustment
5, 133, 227 W8
W8
10 004 912
720.20 S.08
Spare parts
Measuring units K 1a / K 2a
Spare parts drawing of K 1a / K 2a
Drawing for RMG 720, DN 25 and RMG 402, DN 25
*) parts to be kept in stock for maintenance
measuring unit for
underpressure release only measuring unit for overpressure release only,
special version
(without diaphragm rupture safety protection)
measuring unit for
overpressure and underpressure release
4.
4.1.
4.1.1.
4.1.1.1.
partial view A
K 1a K 2a
720.20 S.09
Drawing for RMG 300, DN 25,
and for RMG 330, RMG 332, DN 25 and DN 50
*) parts to be kept in stock for maintenance
RMG 330, RMG 332
4.1.1.2.
RMG 300
720.20 S.10
material
RMG stock no.
K 1a K 2a
item
no. description
1
2*
3
4
5
6
-
-
-
-
7*
8*
9
10*
11
12
13*
14*
15*
16
17
18
19*
20*
21*
22*
23
-
24
25
-
-
-
-
26
27*
28
29
SAV locking cap
sealing ring
spring housing
spring plate
spring plate
setpoint spring:
wire dia. 2,5
wire dia. 3,2
wire dia. 3,6
wire dia. 4,75
O-ring
switch bush, complete
cylinder screw
diaphragm
diaphragm plate
pressure disc
securing ring
ball
O-ring
plug
hexagon socket screw
SAV support, complete
O-ring
securing ring
valve plate, vulcanized
valve plate, vulcanized
main valve body:
ratedPN 16
rated ANSI 150 (p zul 16 bar)
spring retainer
setpoint spring:
wire dia. 1
wire dia. 1,1
wire dia. 1,2
wire dia. 1,4
diaphragm plate, complete
sealing ring
screwed socket
cutting ring
LM
K
GLM
Ms
K
SF
SF
SF
SF
KG
LM/NSt/St
St
KG
St
LM
SF
NSt
KG
K
St
LM/NSt/St/KG
KG
SF
LM/KG
LM/KG
GS
GS
K
SF
SF
SF
SF
LM/KG
LM
St
St
10 000 854
00 020 343
10 010 608
10 001 844
10 000 856
-
10 000 866
10 000 867
10 001 839
00 021 069
-
00 010 150
18 354 902
-
-
-
00 005 108
00 020 371
00 026 066
10 004 895
10 010 585
00 020 243
00 019 093
10 003 580
10 004 942
10 008 454
10 008 455
10 008 563
-
10 000 868
-
10 001 760
10 004 929
00 018 694
10 007 642
00 030 904
Spare parts list for K 1a / K 2a
List for RMG 720, DN 25 and RMG 402, DN 25 (inlet size)
Parts marked by an asterisk (*) to be kept in stock for maintenance:
10 000 854
00 020 343
10 010 608
10 001 844
10 000 856
10 001 838
10 000 866
10 000 867
10 001 839
00 021 069
10 010 612
00 010 150
10 010 610
10 010 611
10 004 882
00 019 131
00 005 108
00 020 371
00 026 066
10 004 895
10 010 585
00 020 243
00 019 093
10 003 580
10 004 942
10 008 454
10 008 455
10 008 563
10 001 826
-
10 001 837
10 001 760
-
00 018 694
10 007 642
00 030 904
material key:
K ... plastic material
KG ... rubber-like plastic material
LM ... light metal
GS ... cast steel
colour:
yellow
bright red
dark red
white
St ... steel
NSt... stainless steel
SF ... spring steel
colour:
yellow
light blue
white
black
4.1.2.
4.1.2.1.
Altri manuali RMG Unità di controllo
Manuali Unità di controllo popolari di altre marche
Festo
Festo Compact Performance CP-FB6-E Manuale elenco delle parti
Elo TouchSystems
Elo TouchSystems DMS-SA19P-EXTME Manuale utente
JS Automation
JS Automation MPC3034A Manuale utente
JAUDT
JAUDT SW GII 6406 Series Guida rapida
Spektrum
Spektrum Air Module System Manuale utente
BOC Edwards
BOC Edwards Q Series Manuale utente
