Special PVC Elbows For Pools?

NullQwerty

LifeTime Supporter
Apr 23, 2008
340
#1
Hey folks,

I had a guy from a local pool store over for a quick quote on an unrelated project. He saw my pipes and first thing he said was:
"Those 90 degree elbows you got don't meet code. They're not meant for pools. You should replace them.". Of course he he offered to do it.

These are just standard white PVC elbows from Lowes/HD plumbing department. So, I went to a few local pool stores and didn't find any special elbows there. Is what he said really true? Or are the standard ones from Lowes/Home Depot fine?

Thanks
 

mas985

TFP Expert
LifeTime Supporter
May 3, 2007
12,126
Pleasanton, CA
#3
Some states are following the APSP-15 regulations:

5.5.4. All elbows shall be sweep elbows or elbow-type that have a pressure drop of less than the pressure drop of straight pipe with a length of 30 pipe diameters.
However, according to the Crane TP410 handbook, a standard ELL 90 meets these requirements. I think the problem is that the 90s at Lowes and Home Depot have no test data behind them so you really don't know if they actually meet those requirements but I would assume they do.

IMHO, that is a short sited requirement because you can get much less head loss by up sizing the pipe instead of using special 90s.
 

chrisexv6

Well-known member
Feb 8, 2008
340
Milford, CT
#4
what you might have are waste elbows instead of pressure rated. You can tell by how much sleeve there is on each part of the ell. pressure fittings will have about 1.5 inches but waste fittings will only have .5 or .75 inches.

You can get pressure fittings from home depot our Lowes...they will be called schedule 40....waste fittings are labeled dwv. Around here Lowes has a far better selection than home depot

Sent from my GT-I9300 using Tapatalk 2
 

NullQwerty

LifeTime Supporter
Apr 23, 2008
340
#7
I think chrisexv6 was right. They were all waste. I think they were fine, but I'm installing a gas heater, so with the plumbing inspector coming by soon for a visit, I just bought pressure ones to replace them with to be on the safe side.

Thanks
 

Isaac-1

TFP Expert
LifeTime Supporter
May 10, 2010
6,711
SW Louisiana
#8
My pool builder used a DWV drain pipe elbow on the return line for my pool, it held for 29 years before blowing out and costing well over a thousand dollars to fix (under concrete, had to get a professional leak detector to locate it, jack hammer up a whole section of concrete floor, fix the broken pipe, new concrete)

Ike
 
Jun 6, 2012
23
#9
NullQwerty said:
Hey folks,

I had a guy from a local pool store over for a quick quote on an unrelated project. He saw my pipes and first thing he said was:
"Those 90 degree elbows you got don't meet code. They're not meant for pools. You should replace them.". Of course he he offered to do it.

These are just standard white PVC elbows from Lowes/HD plumbing department. So, I went to a few local pool stores and didn't find any special elbows there. Is what he said really true? Or are the standard ones from Lowes/Home Depot fine?

Thanks
What brand were the fittings?
 
Jun 6, 2012
23
#12
The Lowes where I live only sells Charlotte and Lasco fittings. The Charlotte fittings they carry are for DWV only. The OP may have gotten fittings that were for DWV only.

A DWV fitting will only fit 3/4 of an inch on a pipe, while a fitting for pressure will fit 1 1/4 inch on a pipe.
 

tjwaggoner

Well-known member
May 19, 2012
88
Ashland KY
#14
Thanks. Good to know. When you speak of DWV is that similar to what I've always called SDR pipe? That's what I have my gutter downspouts going into underground.
 

JasonLion

TFP Expert
Platinum Supporter
LifeTime Supporter
May 7, 2007
37,879
Silver Spring, MD
#16
SDR is a measure of the ratio of the pipe diameter to the wall thickness. SDR doesn't mean anything by it's self, but is always associated with a number, i.e. SDR-11 or SDR-35. Lower SDR are stronger and can handle higher pressure.

Schedule 40 and Schedule 80 pipe has the same wall thickness at any size, while SDR-NN pipe will have different wall thicknesses at different diameters, so the ratio remains the same. 2" Schedule 40 pipe has an SDR of about 15.4.

In common usage, SDR without a number is sometimes used to mean either SDR-26 or SDR-35, both of which have thinner walls than Schedule 40 pipe.
 

Isaac-1

TFP Expert
LifeTime Supporter
May 10, 2010
6,711
SW Louisiana
#18
The main thing you will notice with DWV fittings is that the area for glue to mate is much shorter than on SCH 40 fittings, DWV and SCH40 pipe has the same outside diameter so will fit in either type of fitting, just the DWV fittings are not pressure rated. Also note you will sometimes see sections of larger diameter PVC dual rated as both SCH 40 and DWV, this is mostly to let people know that you can use SCH 40 in place of the thinner DWV pipe, probably also for less than informed inspectors that want to see the markings.

Ike
 

jasonknox

Platinum Supporter
May 4, 2010
300
SW Georgia
#19
I don't know about code but when I plugged the equivalent lenghts for the sweep elbow (5.7) and the traditional elbow (8.6) (The Engineering Tool Box) in to my plumbing model my head pressure only went up 1.2ft. based on 65 GPM. It may not meet code but I deem it unnecessary to replace if you can get away with it.
 

scooperhsd

Well-known member
May 10, 2009
395
Youngsville NC
#20
Based on this thread - I got rid of my two DWV 90 degree elbow that I used to offset to get around some electrical work. As usual - it snowballed a little - but I did get everything all glued in and running again - this time, with enough clearance to go around my sand filter...