Regarding the issue of control valves equipped with interlocked solenoid valves
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The company originally had a SAMSON control valve, equipped with a solenoid valve for ESD protection; it was usually controlled via the DCS, and the solenoid valve was installed before the positioner. Later, during the company’s renovation, another control valve of this type was added, but the brand was changed to the domestic brand Chuanyi; its solenoid valve is installed between the output of the positioner and the grinding head. I’m not sure what the difference between these two is
1. If the air supply is cut off suddenly in front of the locator, it can regulate the air release process. 2. If the air supply is cut off suddenly in front of the grinding head, one has to hold back the air; once it is released, everything goes dark
The solenoid valve is located after the positioner; once it activates, it quickly cuts off the air supply to the diaphragm head, and at the same time the instrument air inside the diaphragm head is rapidly exhausted, thereby enabling rapid sequential switching. With the solenoid valve placed after the positioner, the interlock switch of the valve will definitely be slower. ——The possibility of an installation error cannot be ruled out.
Installing the solenoid valve after entering the positioner allows for a faster response when the control valve loses air pressure in case of a failure, compared to installing the solenoid valve earlier.
Typically, the interlock solenoid valve should be installed in the pneumatic pipeline between the valve positioner output and the diaphragm head of the control valve.
I only know that they are all installed between the positioner and the actuator, but why does this make the operation faster? I thought about it but didn’t understand; it seems to be just a tiny bit faster in theory.
SAMSON now also has temporary staff; the assessment is complete