How Solenoid Valve Works?

The air flows to actuator when solenoid valve is energized, and the air is vented from actuator when solenoid valve is deenergized(reverse case available).

How Solenoid Valve Works?

1-way or 4-way valve is applied in case of emergency isolation of control valve, however 2-way valve is applied to block the air signal by electric signal, and 3-way valve is applied to emergency isolation or emergency opening of diaphragm actuator or single acting actuator. 4-way valve is applied to dual acting actuator.

We can arrange as below picture if we have to install all accessories in turn.

In case of small size valve, solenoid valve is applied if the fast vent is required since the vent from positioner is made slowly.

The location of lock-up valve is usually installed nearest to the actuator.

Author - Stanley Park


I have a query ! Please see Below picture

The valve has a double acting piston actuator and I want the valve to be fail last. But as per the above configuration I don’t think we can achieve fail last position. can you help me with the same?

I think when the IA pressure goes down the lock up valve will shut trapping the pressure at it’s outlet! This will keep the air operated solenoids always open allowing the air from the actuator to escape.

Do you think the above configuration is correct to achieve fail last position in case of IA failure?

Thanks for your help



The picture was not opening, upload again, use upload button in this forum editor.


Check all Solenoid Valve Related Articles - Check Here

1 Like

Hi please check if it’s visible now?

1 Like