Pump inlet minimum straight length.

czb182

Well-known member
Oct 20, 2020
57
North Virgina
Regarding the earlier recommendation of having a three way valve on pump outlet did waste. I’m looking at my Jandy cv460 and I see a 2” drain outlet at bottom. I’m guessing I can just use this instead? I haven’t checked whether it bypasses filter or not, hopefully so.

regarding check valves , apparently Jandy recommendeds 16” of head to keep it well sealed. That’s not gonna happen , but I will ask PB if they can move it as low as possible on the vertical pipe, although I guess they would need 4 instead of 1 which maybe they wouldn’t be so happy about. That would also reduce head loss in some scenarios I think because if lower flower rates on individual pipes

I put a 90 degree check valve on heater outlet going to swcg, per Jandy versus plumb template. Seems like it would actually be better to have sweep on outlet with a straight check valve.
 

JamesW

TFP Expert
Mar 2, 2011
24,837
If you put the check valve after the pump, it will work better than keeping it on the suction.

When the pump is off, the static drop will keep it closed.
 

czb182

Well-known member
Oct 20, 2020
57
North Virgina
regarding turbulence on water going to pump inlet. You mentioned lower speed of water to reduce turbulence. I’m wondering if this really only matters for short pipe leading to pump. Like if whole run was 2”, if the pipe expanded to 2.5” in foot before pump, is that all that matters? The thinking is that velocity should immediately slow in larger pipe.
 
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