Pressure relief valve query

[FAIZANYOUSUF]

Hello experts,

I would like to ask can I use pressure relief valve to release the pressure from the system that generates excessive pressure time to time i.e. cyclic because i have heard that pressure relief valve are designed to work very rarely i.e. sometime system undergoes through high pressure? Actually I have an option to use in place of flow actuating valve.

Currently, the system faces excessive pressure time to time. I thought to use flow actuating valve to regulate pressure but though came in my mind why not go for PRV?

 

[RVAmeche]

This would probably be better suited for the Safety Relief Valve (PSV) forum.

What is the service? What is the magnitude of this "excessive" pressure and do you have any idea the cause? Are we talking 15% above normal operating presusre but still below the design pressure for all the components in the system? If thermal expansion is generating pressure, a small PSV to a product recovery tank/back to the storage tank would be okay.

Anyways, this isn't a good idea. PSV's are not just typical valves and when they go off it should be a big deal in your plant because they're designed to protect the system/vessel. If your system is regularly generating excessive pressure, I'd rather determine the cause and resolve it or handle the excess pressure in a different manner.

If it's pump/compressor/actuated valve speed/surge related that should be handled in a different way with a PSV as a final safeguard for the system.

 

[gwalkerb]

PSVs are intended for emergency or upset conditions. If you know that the pressure could rise above system limits as part of normal operation, you should be using a regulator designed for that type of service.

Or of course, the system should be designed for these pressures from the beginning. Regardless of what you do to solve this issue, if it's possible to exceed the design pressure of the system (and it certainly sounds like it is), there should be permanently installed relief valves, but these would be separate from regulating valves that intended for regular service.

 

[mk3223]

IMO, the PSV, as a safety device, shouldn't be used for the operation. May verify with your Local AHJ that the operation above the design condition may violate the Codes requirements.
In order to protect the plant due to any process or operation upsets, the design and O&M requirements of the PSV are totally different from the regular process components.

 

[LittleInch]

If your process does this as a matter of course then you should be using some sort of regulating device like a back pressure control valve (many are self contained) with a PSV as a safety backup.

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