2 45's or one sweep 90?

[FMitchell]

Pool plumbing is, virtually, always under something you can't easily remove, but there is "always a bigger hammer."
Do yourself a favor and use the very least amount of 45s, none is better, underground. Ask any leak detection/repair company that does the repairs and they will tell you that most under -ground, -paver, -deck, leaks are at those fittings.

The builder told me they did sweep 90s but in fine print in my estimate it said, two 45s to make a sweep 90... Should I tell them I only want true sweep 90s unless a 45 is the only option for a certain turn. It seems putting two 45s has more chance of leaking than one fitting.

 

[Bill1974]

Flow is almost the same. But 45's means twice as many potential leak points.

If properly glued I don't see 45's as a risk unless there is a noted issue with 45's that I am not aware of. Make sure the sweep 90's are SCH 40 and not DWV only fittings. The depth of the socket on a SCH 40 is about twice as deep as a DWV. If you are looking at the marking on the fitting, some SCH 40 are also marked with DWV as well (just because it has DWV doesn't always mean its the incorrect fitting). A SCH 40 can be used in place of a DWV fitting not the other way around.

 

[1poolman1]

Flow is almost the same. But 45's means twice as many potential leak points.

If properly glued I don't see 45's as a risk unless there is a noted issue with 45's that I am not aware of. Make sure the sweep 90's are SCH 40 and not DWV only fittings. The depth of the socket on a SCH 40 is about twice as deep as a DWV. If you are looking at the marking on the fitting, some SCH 40 are also marked with DWV as well (just because it has DWV doesn't always mean its the incorrect fitting). A SCH 40 can be used in place of a DWV fitting not the other way around.

Quote:

"Do yourself a favor and use the very least amount of 45s, none is better, underground. Ask any leak detection/repair company that does the repairs and they will tell you that most under -ground, -paver, -deck, leaks are at those fittings."

Don't know why, but every trade show that has had a leak-detection company booth will also have an array of pipes cut out from underground and the majority of those are 45s unless it was a copper line or a tree-root issue.

 

[FMitchell]

Thank to both of you.
I should stick to wanting sweep 90s it sounds like. Are you saying on the PVC SCH 40 it should say on the pipe SCH 40 and some will have SCH 40 and DWV?

 

[Dirk]

Thank to both of you.
I should stick to wanting sweep 90s it sounds like. Are you saying on the PVC SCH 40 it should say on the pipe SCH 40 and some will have SCH 40 and DWV?

Yes, sweep 90s wherever possible. No dual-45s. If you see DWV then that is the incorrect part, not to be used. You can double-check by looking at the depth of the glue surface:

DWV, AVOID!

Schedule 40 Sweep, OK!

 

[JamesW]

Pool PVC (polyvinyl chloride) should be marked "Schedule 40". Schedule 40 PVC is made for water under pressure. If the pipe has ASTM D 1785 on the pipe, it's suitable for pressure applications. A rating of ASTM D 2665 means non pressure applications and should not be used for pools.[1]

A pipe can be dual rated ASTM D 1785 and ASTM D 2665, but it has to say ASTM D 1785 if it's going to be used for pressure.

The pipe should also be labeled NSF-PW (National Sanitation Foundation - Potable Water) and Schedule 40 PVC.

Note: ASTM D1785 is for pipe.

ASTM D1784 is the specification for the PVC material.

ASTM D2466 is the correct rating for the fittings.

PVC Repair - Further Reading

www.troublefreepool.com

45s (and 90s) can be cracked over time due to the pipe being forced into trenches that are not exactly 45 degrees, which causes stress on the fitting.

Sweep 90s are better than regular 90s, but it is not really that big of a deal as long as the pipe is sized correctly.

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

 

[JamesW]

Standard Specification for Poly(Vinyl Chloride) (PVC) Plastic Pipe Fittings, Schedule 40

AbstractThis specification covers poly(vinyl chloride) (PVC) Schedule 40 pipe fittings made from four PVC plastic compounds and intended for use with Iron Pipe Size (IPS) outside-diameter plastic pipe. Fittings fabricated by welding are not included in th

www.astm.org

 

[FMitchell]

Thank you!! for all the info.

I had a thought... if 45s are the ones most common with a leak could it be that pool plumbers use more of those and not so many 90s or sweep 90s? I know a single 45 has better flow on their own... are 45s on their own still prone to leaks because they have more pressure from doing a turn?

I went to a dig of a builder I am considering. They claim they focus on more efficient plumbing which is what I want. I saw they used a lot of 45s to make their turns but a single 45. From my research I should not use street elbows worst for flow.

I found one laying on the ground near the dig and I believe I saw some in the line. I have a picture below and I think they could have used 90. Another picture the one on the ground with 5 runs all next to each other they are using 90 sweep and 90s... could I have had all sweep elbows instead of short 90?

There is a picture of two 45s making a different shape than a sweep?

on a straight run is it ok to use a street spigot or is it the only way to connect the pipes? Is there a better way if flow is a priority?

How about a T I think it goes into a street elbow or is that a reducer... ?

I am not a plumber just read a lot online and watched videos so I can be more knowledgeable to pick a good builder.