49
REV
AL 182
Use, maintenance and warning instructions
MEDIUM PRESSURE REGULATOR
|
DESCRIPTION AND OPERATION
|
REV. 00
EN
A
A
9
7
1
3
8
10
2
4
5
6
C
U
pstream
pressUre
D
ownstream
pressUre
Fig. 4.11.
Built-in slam-shut valve SA
OPERATION
In the control head (C), the downstream pressure (Pd) acts on the diaphragm (6) of the control pressure switch (2), which,
integral with the control shaft (8), receives an antagonistic force through the springs (4, 5), which causes the plug (1) on
the reinforced gasket (9) to disengage.
In the event of tripping due to a pressure surge:
• the downstream pressure (Pd) exceeds the calibration value;
• the load on the diaphragm (6) increases until the resistance of the spring (4) is overcome;
• the drive shaft (8) moves the feeler gauge (10), by means of the cam, to the opening position, releasing the lever
mechanism.
In the event of a tripping due to pressure drop:
• the downstream pressure (Pd) decreases below the calibration value;
• the spring support (5) stops the stroke on the body stop;
• the drive shaft (8) moves the feeler gauge (10), by means of the cam, to the shut-off position, releasing the lever
mechanism.
In order to reset the built-in slam-shut valve, the lever (3) that engages the control device (7) of the mobile system must
be operated.
Summary of Contents for REVAL 182
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