Need check valve before 7 foot high pump?

[waconiglio]

I'm redoing this manifold while changing the pump to a VSP. Pump sits 7 feet above pool, and these check valves are presumably here to prevent the lines from draining when the pump shuts off. 1) When everything is nice and tight, it holds pressure and the check valve is unnecessary. It's often gummed up with leaves anyway due to a poorly designed skimmer, but that's another story. 2) When I clean the filter basket or something leaks above ground, the check valves don't seal well enough, and it drains anyway. Takes 10 minutes of dry-running to re-prime or else plugging a port and filling with a garden hose. 3) I don't know what the springs are rated, but they cost me valuable head, which pushes the impeller into cavitation, particularly when running a suction-side cleaner.

Which would you do?

A) Move the check valves above ground and put unions around them for cleaning and lubrication.
B) Drop the check valves and leave the rest as-is.
C) Drop the check valves and diverter and individually valve the lines.
D) Something else...?

 

[JamesW]

I would put a good Jandy check valve at the pump discharge and convert the two check valves to regular valves.

As long as the pump and suction are air tight, the check valve will work on the discharge.

When you have to work on the pump, close both line valves before opening the pump lid to prevent loss of prime.

The Jandy check valves are the same body as the NeverLube valves.

Just buy two NeverLube complete valves and remove the entire assembly from the valves and install the assembly in the current check valve bodies.

When reinstalling the screws, do not crossthread the screws. Slowly rotate the screws counterclockwise until you feel them drop into the original threads and then tighten clockwise as normal.

Are the check valves Jandy check valves?

What is the suction vacuum when the pump is running?

 

[waconiglio]

Thanks! I would love an in-place fix! One of the check valves is underground, and the other is nearly so. Should I get an underground enclosure and modify it to fit around the pipes? There's already a check valve on the pump outlet.

Yes, they are Jandy, and I start to hear cavitation at -12 to -14 in-Hg, although the pump can make -21 if lightly loaded to the returns.

 

[JamesW]

You can just remove the flappers in the check valves and use the existing three-way valve to close the suction when you need to service the pump.

 

[HermanTX]

One of the check valves is underground, and the other is nearly so. Should I get an underground enclosure and modify it to fit around the pipes? T

Since you want to be able to move the valves easily, based on your picture, you may want to put a box or something to hold the soil from falling in so you can access the valves without much trouble.