ELEKTROGAS – Technical Sheet EE175 - 0117
4-16
Functioning and
application
The VMH type valve is a safety shutting
device using auxiliary power supply.
When it is de-energized, the spring pushes
on the seal disc, keeping the gas passage
closed. In this condition the inlet chamber is
filled with pressurized gas that forces on the
disc, improving the seal.
When the actuator is powered, the relief
valve closes, the pumps starts and the
pressurized oil pushes the piston. The disc
opens against the combined force of spring
and gas pressure.
When the disc reaches the end stop, the
pump is turned off and only the relief valve
is consuming power.
If the power supply is shut off, the relief
valve opens and the disc closes rapidly,
interrupting the gas flow.
Fig. 1 shows a sketch of a VMH valve.
This kind of valve is normally installed as safety and regulating device in gas trains, for industrial
applications and gas firing systems. Fig. 2 shows an example of installation, in combination with
other Elektrogas devices.
WARNING
Location and mode of installation must be in compliance with local rules in force.
Gas
network
Consumer
Ball
valve
Valve
leak
tester
Gas Filter
FG
Pressure
regulator
Pressure
switch
PSG
Pressure
gauge
Hydraulic
valve VMH
with PCS
Hydraulic
valve VMH
Fig. 1
Fig. 2
Solenoid valve
VMR-VML