Quick Exhaust Valve For On/Off Valve Actuator

Hi jitesh5979,

If the leak through the solenoid valve is at a low rate that causes a pressure differential across the quick exhaust valve it will operate and dump the air from your valve actuator.

However, I would try and solve the problem with the solenoid valve. It might be working at too high a pressure and therefore not seating correctly.

Best regards,

John

Is it a spool valve or a poppet valve ? The first type is NEVER tight. It has a radial gap and through it can you fluid leak. If it is a poppet valve it can be possible that the poppet does not every time come well on its seat thus the leak.

How are the solenoid valves being used?

In one of our liquid systems we also had solenoid valves that would fail to close completely. The problem turned out to be metal shavings that slowly worked their way downstream until some would become lodged under the spool of the solenoid. The problem persisted for years.

You may want to inspect the solenoids for debris.

It is possible to use a quick exhaust valve on a on/off valve.

Keep in mind that valves slamming shut can cause problems, (shut-off pressure can increase, your process can be affected, etc.)

It is indeed better to solve the problem where it started as mentioned above.

Hi,

If I understand your question, the valve which remains a little open is the main on-off valve, not the solenoid. In fact you wrote "sometimes the valve doesn't close fully with spring force and remains a little open."

When this happen, the solenoid valve is venting the actuator diaphragm or piston and the spring force returns the valve to its fail close position. Are the system conditions (ΔP, flow rate, etc) the same in all cases, when it fails to close and when operates right?

Check the actual lower bench set and compare it with the required, it may be too near to the minimum allowable value and the spring cannot close completely the valve under some circumstances.

Kind regards