Pump Bypass Piping (Not Recycle Line) 1

[DGrayPPD]

I am trying to find some guidance or literature on bypass piping from pump suction to pump discharge and I am coming up empty handed. This is not a minimum flow recycle bypass.

We have a 3" NPS pump suction, 3" NPS pump discharge, and 2" NPS pump bypass that travels from the pump suction to the pump discharge.

I am trying to find some guidance or literature that states whether or not the bypass piping should be the same NPS as the pump suction. The pumps are being used to unload RGP from tanker trucks. In the event that the tanker truck pumps are used, the RGP will bypass our pump to the discharge piping and travel to the storage tanks.

 

[pennpiper]

IMO,
1, Make the Bypass line the same size as the rest of the piping.
2, Arrange the piping and Valving so the Bypass can be isolated if in not use.
3, Arrange the piping and Valving so the Pump (via the Pump Suction & Discharge Valves) can be isolated

This way if the Pump fails or needs maintenance it can be shut down but the Unloading can continue with the Truck mounted Pumps.

Sometimes its possible to do all the right things and still get bad results

 

[DGrayPPD]

Thanks pennpiper. My opinion was that they should all be the same size. My argument as to why was lacking.

 

[EdStainless]

If they expect the same flows then they should be the same size.
pennpiper's advice about isolation valves for both bypass and pump is right on.
When people will complain about the cost of the extras valves ask them if they would rather shut down the operation.

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P.E. Metallurgy, Plymouth Tube