Rupture disc relief for PD pump

[Nova N]

I am in the process of designing a relief device for a PD pump. I have 2 questions regarding the rupture disc as a relieving device for the PD pump.

1) Is the discharge from the Rupture disc allowed to go back into the pump suction?

2) The pump inlet and discharge piping is 1/2" diameter. I have a 1" rupture disc. Can I swage up to a 1" immediately before the rupture disc?

Thanks
Nova N

 

[Latexman]

I usually put a recloseable relief device (PSV) on a PD pump, so it doesn't have to be replaced before the pump works properly again. Some pumps can be purchased with an internal relief. It's always recloseable. Why do you want to use a RD?

Good luck,
Latexman

Engineers helping Engineers

 

[RVAmeche]

If you want to use an RD on a PD pump, I'd recommend a burst sensor or something else tied into the controls to shutdown the pump.

1) This is typically not preferred, since it'll just short circuit thru the pump and overheat. Go back to a tank if possible.
2) I believe you need a minimum of 1" inlet piping for a 1" RD, similar to PSVs. Ask the manufacturer. You should be doing sizing calculations for the RD/piping to ensure the losses are acceptable and not just assuming a 1" RD is good.

 

[don1980]

This is a bad application for an RD. Frequent premature failures should be expected. Use a relief valve.

 

[Nova N]

Fellow Engineers, thank you for the detailed responses. We are exploring PSV's now as a suitable option.

 

[vladrath]

Does your pump manufacturer not offer an internal relief option? Are you sure that your pump currently does not have an internal relief device?

In either case a RD is not a good option for reasons already discussed.