Pilot Operated Diaphragm Valve Highest Demand In process industry Spare-diaphragm | Page 3

Normaly closed or open
Body material: Brass, Stainless steel
Hermetical separation of fluids from the operating mechanism by diaphragm
Compact design
Robust construction
More information about pilot operated diaphragm valve:
Pilot operated diaphragm valves utilize an auxiliary, much smaller, adjustable
spring loaded diaphragm valve to assist the main valve opening and CLOSING.
The main valve may also be spring loaded, but process air pressure, through
use of a diaphragm arrangement forcing the main valve closed, is the main
source of closing pressure (the higher the sealing force!!).
When the process pressure reached the 'set point' the pilot valve opens and
releases the pressure on top of the main valve, which then immediately fully
opens. The 'supply' of process air to the pilot and closing diaphragm is
controller through a carefully sized hang-up outlet so there is no possibility of
the pilot being unable to dumps the diaphragm valve closing air pressure.
The pilot valve assembly is very similar to a pneumatic 'spool valve' assembly
so the on/off exclusive is very fast.
Pilot operated diaphragm valve are useful the maximum allowable (relief)
pressure is not very much higher than normal operating pressure, and both a
high. A quality spring operated valve is very sensitive to , instability , air when
relief, leaking to re-seat under those conditions. However, the precision pilot
assembly, which has a small, but crucial to operation small leak rate past the
pilot cylinder, is not suitable for dirty air containing any solids or materials
which will plug up the pilot valve assembly.