Self-Contained Hydraulic Emergency Shutdown Systems actuator Spring 1

[Valveusa]

We are working on HIPPS 3" CL 2500 Self-Contained Hydraulic Emergency Shutdown Systems
gate valve . The ESD control panel include two HP and LP Hydraulic Pressure switch. Fail close time <3 sec and displacement 3.5" . My question is how to calculate the actuator SPRING for quick action ?
Thanks
AL

 

[gerhardl]

What are you trying to calculate? Mathematics of a spring movement, or the more complex interaction of all forces of influence when closing? For side A (Of actuator)(closing force): spring (plus oil pressure pr area unit times area if oil is present additionally on this side). Side B (of actuator): (Net)Oil pressure pr area unit, times area, plus resistence of flow through evacuating port.

One of the most important limiting factors for closing speed will be flow speed through the evacuating port of the actuator. Rough estimates can be made of total oil pressure evacuation time using estimated max flow speed pr. minute times area of evacuation opening.

Be sure that this is OK before selecting spring force against forces inside actuator and valve operating force.

 

[al1979]

Valveusa
I don't think you can achieve <3 sec just by spring release action especially springs are heavy and has considerable inertia.
Search for quick closing actuator manufacturers. They use extra pressure in spring cylinder forfast closing. Sorry for half information but thats all I know.

Cheers !!!