Maximum back pressure on a CSV

[rtodom12107]

We are designing an irrigation system for a small Pecan orchard and had a question concerning maximum back pressure on 4" well with a 5 hp pump.  The flows have been tested as the following:

GPM                  PSI
68                     0
60                     10
57                     20
54                     30
57                     40

We are needing 25 gpm @ 25 psi.  What will our back pressure be on this 5 hp pump?  Will it create any problems with checkvalves, pipes, or pumps?

We did a similar installation with a Vermad valve on a different site and blew a rubber check valve in the well supply pipe.

Thanks for your time
Randy

[Cary Austin]

I am guessing you have a 55GS50 pump?  If so and it will produce 68 GPM at 0 pressure, then the water level is at about 190'.  With a water level at 190' that pump can develop 104 PSI backpressure.  Any part of the pipe or fittings that won't handle 104 PSI is weak and needs replacing anyway.

I don't know what kind of "rubber check valve" would blow out from backpressure.  But it sounds like a bad check valve to start with.