I have to purchase anti-surge control valves which require an opening stroke time of 2 sec. max.

The valves are globe+cage type with spring-diaphragm actuator (fail-open) with a "flow tends to open" plug.

The valve supplier propose me two ways to achieve the fast opening feature :

option 1 : a quick exhaust valve to speed up the valve opening ensured by the spring return

option 2 : an air booster to increase the supply pressure to the actuator

What is the more appropriate solution for anti-surge application ?

In addition, is there any trap or hint  in the selection of anti-surge control valve ?

The most appropriate method of control depends on how you want the valve to act.

If you need the valve to stoke fully open on 'trip' within two seconds but do not require modulating control within the two seconds then a separate high capacity solenoid can be used as a dump valve to evacuate the actuator and a standard positioner can be used for control once the valve is fully open.

If you require control modulation in 2 seconds then the first step would be to select a high capacity positioner which may meet the speed requirements(Masoneilan 7400-200 is a high capacity pneumatic unit, there are high capacity electropneumatic positoners available). Depending on how accurate you wish to control, flow boosters and/or quick exhaust valves can be used (boosters/exhaust valves tend to increase overshoot on position)

The speed achievable depends on the volume of the actuator and the stroke of the valve - the higher the volume & stroke, the more boosters etc will be required.

Depending on the fluid and duty you need to be aware of  auto-refrigeration (Joule-Thompson effect)which will reduce the valve operating temperature. Many anti-surge valve have low design temperatures because of this  effect.

Selecting anti-surge valve is not a big deal, because all manufacturers will promise you the moon.
Solution with boosters is giving us a big trouble, with opening times over 10 sec in control, while no problem in opening in less than 1 sec through the solenoid.
Moreover valves get stuck if closed 100% and we had surge twice already, thanks must be to to ESD push-botton.

I strongly suggest you to specify in data sheet that opening time in less than 2 sec is in CONTROL mode, not only in trip mode. Expedite the manufacturer many times and put in the spc that they must prove the opening time via controller at their factory and at the final location.

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