PSV label changed to PV

[airbus]

From a PSV evaluation, it was determined that there are no applicable relief cases associated with a couple of PSV installed at the discharge line of a couple of small sampling pumps at a Blender system. From the study it was recommended to remove the PSV's from service. However, in order to still have "pump protection", engineering wants to leave PSV's in place and change their equipement name/label from PSV to PV. Is this a normal practice? Can it be done? Is there a regulation to refer to?

 

[MikeClay]

It all depends on what "pump protection" means. If the PV is for minimum required flow, then the PSV is not needed. However, a PSV should not be used for pressure/flow control. A properly sized backpressure regulator or pressure control loop should be used.

If PV is to prevent pump or piping overpressure, then there should be a PSV.

--Mike--

 

[Chance17]

The API standards use to exclude external safety valves if the pump had electric motor less than 15-HP.
But all of this has been abandoned for nearly 20-years.
The standards are API-674, API-675, API-676.
If you want to follow API, you'll need an external PSV regardless how small the pump.
There are exclusions when using steam of Air for motive power which can be self limiting.