PSV on pump inlet/outlet

[NMendes]

Hello there, first time here.
I have a doubt concerning PSV between pump outlet/inlet.
The pump is centrifugal, built according to API 610. The fluid is gasoline. The flowrate is 250m3/h and pressure on the outlet is around 10barg.
Should I put a PSV, connect outlet to inlet, opening to the inlet, for recirculation purposes? Or is the pump prepare for that, in case of obstruction or valve closing on the outlet side? For what I saw so far, there are only small Thermal relief valves. Thanks!!

 

[BigInch]

If you need to run at low flows for extended periods, recirculation could be a good idea, but you should not recirculate through a PSV. Use a control valve with a PSV downstream of the control valve to protect suction piping, if that piping is not rated for pump discharge pressure at shutoff conditons.

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"Being GREEN isn't easy." Kermit

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[NMendes]

Thanks BigInch.
On the case of a centrifugal pump, if you pump against close valves, the pressure only goes so high according to the project parameters. If the pumps gives 10barg at the outlet, and if you a close a valve, the pressure will not go higher then this. Is this true?
After a while the liquid will begin to heat up because of the movement, but apart from that, the pressure will not rise. Am I thinking correct?
Thanks!

 

[BigInch]

Initiallay pumping against closing discharge valves the discharge pressure will reach suction pressure plus the "shutoff" head (its pressure equivalent) as flow goes to zero. The pump will begin internal recirculation and start heating the gasoline and itself. If it continues to run, overheating, vaporization of product, ignition and fire/explosion can result. Temperature sensors connected to a shutdown switch are standard operating practice when pumping petroleum products.

"The top of the organisation doesn't listen sufficiently to what the bottom is saying." Tony Hayward X-CEO BP
"Being GREEN isn't easy." Kermit

http://www.youtube.com/watch?v=hpiIWMWWVco

http://virtualpipeline.spaces.live.com