Tie-in of sump pump discharge to a centrifugal suction

[JKU11]

We are installing a sump pump into a water transfer facility that will pump off the draining from water filters into the suction of a centrifugal pump. We have installed a wye strainer and check valve on the disharge of the sump which is rated to 35 psi output. The centrifugal's output is upto 65 psi, thus the reasoning for placing the tie-in into the suction. My question is, how can I determine the Sprng tension required on the check valve to overcome the suction that the centrifugal is creating.

 

[bimr]

I assume that you are concerned with siphonage when the sump pump is off.

You might be better served if you installed a back pressure check valve. Here is an example:

http://www.kthsales.com/website/vendors/pom/PDF/RVDT.pdf

 

[JKU11]

You are correct we are concerned about siphonage. Thanks for the link. That looks like it may be the option to go with. I am still uncertain as to how to calculate the psi rating we need.

 

[bimr]

The data sheet has the overpressure rating. It also says that other size springs are included should you desire to change the pressure rating.

 

[JKU11]

Thanks, your right. In my scanning of the doc I missed the "infinitely adjustable from 5 PSI to 100 PSI" statement. I think this will work great. Appreciate the insight.