Are sweep elbows/90s more useful on suction side or pressure side

[everthustodeadbeats]

If I have a limited number of sweeps versus regular 90s, should I prioritize using them on the suction side (before the pump) or pressure side (after the pump)? Or does it not matter, and the head loss is calculated on a system-wide basis, no matter where any individual fitting is located within the system?

 

[JamesW]

Using them on suction is better than return.

However, make sure that you are using the correct size pipe.

Pipe Size and Flow Rates.​

You want to keep the water velocity below 6 ft/sec on the suction and below 8 ft/sec on the pressure side of the pump.[7]

Pipe Size	6 ft/sec	8 ft/sec
1.5"	38 GPM	51 GPM
2"	63 GPM	84 GPM
2.5	90 GPM	119 GPM
3.0"	138 GPM	184 GPM
4.0"	235 GPM	312 GPM

Equipment Pad Best Practices - Further Reading

www.troublefreepool.com

 

[everthustodeadbeats]

Thanks. I don't know what the flow rate is. The pool is 50 years old and everything is underground except for the pad. I am replumbing my pad which is currenly 1.5" pipe with a lot of turns and convoluted pathways. I am changing the pad plumbing to 2" pipe and also simplifying the path with fewer twists and turns. Hopefully I will see some marginal improvement, and at least I don't think that whatever changes i make will make the flow rate worse.

 

[everthustodeadbeats]

Another question: I have an existing 2-way valve that's glued into the 1.5" line. The valve supports 1.5" inside the fitting and 2" outside the fitting. If I cut the outlet flush with the fitting and glue 2" around the fitting, should I remove the existing 1.5" pipe that's glued into the fitting (either with a heat gun or fitting saver drill bit) or just leave it in? Even though it is restricting the flow a little, at least it's smooth.

Or I could just leave 1.5" pipe on both ends and add a bushing after the valve to expand the line to 2". What's the best option?

 

[1poolman1]

Another question: I have an existing 2-way valve that's glued into the 1.5" line. The valve supports 1.5" inside the fitting and 2" outside the fitting. If I cut the outlet flush with the fitting and glue 2" around the fitting, should I remove the existing 1.5" pipe that's glued into the fitting (either with a heat gun or fitting saver drill bit) or just leave it in? Even though it is restricting the flow a little, at least it's smooth.

Or I could just leave 1.5" pipe on both ends and add a bushing after the valve to expand the line to 2". What's the best option?

Either way is fine, you won't notice any difference in that short distance.

 

[DavidArmenB]

If they are ball valves, change them all out for diverter type valves like the Jandy.