Replumbing - couple of questions

[jeffbrig]

I'm plumbing a new Hayward VS pump and SWG for my pool. I have 3 1.5" drains combining into a 2" pipe before the pump. Hayward recommends a 10" straight length of pipe into the pump (5x pipe diameter). I would like to put a ball valve on the inlet line, to make pump removal/servicing/priming easier in the future (pump has unions on inlet/outlet). Question #1, if I have 2" plumbing and a 2" ball valve, can I consider the ball valve part of my straight run? My engineering brain thinks "yes", but would love a second opinion to back me up.

I'm planning to do the entire pad in 2" PVC, where the previous pump and filter were done with mostly 1.5" plumbing. I expect much less head loss with the 2" fittings, allowing me to run the VS pump at a lower speed to get the same flow.

Other than the ball valve before the pump, I'm trying to decide if I need any others. Any maintenance benefit putting one between the pump and filter? What about around the SWG? At first I was thinking to put them everywhere, but now I'm questioning the benefit. When servicing the pool, if I close the inlet valve, shut off the pump, and open the filter, the water will gravity drain back to the pool, emptying the filter and SWG for maintenance. That's good enough, right?

The pool has two return eyeballs, and they are split underground off the same return line, so no valves to control/balance the returns.

 

[Jimrahbe]

Jeff,

I can tell you from direct experience that you won't be able to tell any difference between the pad being plumbed with 2" vs. 1.5".. I suspect there is some theoretical difference, but you won't be able to see it.

I would still plumb the pad with all 2" just because it makes it uniform and easier to do, but just don't expect any real flow/speed difference.

I am not a fan of ball valves anywhere...

As far as the 5 x pipe diameter rule, it is also more of a theory thing... We have seen pumps with 90 degree elbows right at the pump and they seem to work just fine. I would include the valve in the pipe length...

Good luck with your upgrade project... You will love your new Saltwater pool...

Thanks for posting,

Jim R.

 

[jeffbrig]

Jim, thanks for the super quick response. I do appreciate it!

My desire to use 2" is probably a carryover from prior experience with saltwater aquariums - high flow, low pressure pumps that were VERY sensitive to head pressure. It wasn't unusual to use a 1/10 or 1/12 hp pump, and almost all the restriction came from pipe friction and fittings. Pools pumps are HUGE by comparison, and can handle a lot more head pressure.