SDR-21 or Schedule 40 PVC

[nrc17gto]

Hi everyone,

Before too long we plan to work on digging the trench for the water line to our house build. It is going to be around 1700'. I have gotten a few mixed suggestions from pipe suppliers on what I should use. One is highly recommending the SDR-21 pipe that has gaskets built in. The other just suggests Schedule 40 with bell ends. I was originally thinking the schedule 40 but I have just learned of this SDR stuff.

What are your thoughts? Any experience with the SDR-21?

Thanks,
Nick

 

[SPIKER]

I would look at roll type poly tubing and forgo ANY joint type tubing. Chance at leaks are greatest at a joint and damage from shifting or weight from above is much greater for the joint and hard type materials such as the ones mentioned.'

Mark

 

[Qapla]

What size pipe are you using?

We have built mainlines with solvent PVC (schedule 40) that are much longer then the distance you mentioned and have not had any problems with the joints as long as they are properly glued. For anything 4" and under we have never needed anything other then solvent PVC.

Keep in mind, I am in Florida and we do not have a "freeze line" to worry about. But, properly buried at depth, PVC should work just fine.

 

[EddieWalker]

First off, SDR stands for Sewer Drain and is not to be used for anything under pressure. It's strictly a drain pipe.

Do not use poly. It stretches in the ground until it breaks, then you have to fix it, and once you fix it, it's just a matter of time until you have to fix it again.

Same thing with Schedule 40. It will break on long distances. The problem is caused because the ground moves with the freeze that cycle. Even if you completely enclose it in sand, like is required in some areas, but not everywhere. The ground moves all the time. In some soils, it's measured in inches over short distances!!!!!

Water lines with gaskets allow the pipe to slide in and out of each other over long runs and is the current best thing you can buy. You have to pay attention to what you are doing when you install it, but once it's installed properly, you will never have any problems with it.

C-900 or something similar is what you want to be looking for. Be sure to get the grease to put it together. On long runs, it's also a good idea to put a small amount of bleach crystals in each joint. Then when you pressurize the line, you need to bleed the water out for awhile to get the bleach and contaminates out of the line before drinking it. On bigger lines, you have to get a water test to be sure it's safe to drink. If you don't put the bleach in there, you don't have any idea what you will be getting out of it.

Good luck,
Eddie

 

[avillahdw]

As a hardware store owner with one if our primary lines being plumbing, I would much rather sell someone belled end sch 40 to be glued than gasketed pipe. The gasketed pipe, if not properly "anchored" periodically on long runs, will blow apart, particularly if you have any elbows. The only thing holding it together is its inability to move and when you pressure test it in a ditch, the odds are it's going to move. I ran an 1100' foot service with 1-1/2" glued sch 40 and have had zero leaks in the 8 years of service. As for roll poly pipe, I would bet you won't find a continuous roll 1700'+ in length, meaning somewhere you are going to have couplings. Even with the "tuff tube" service pipe, if you have even moderately rocky soil, over time you will have leaks from expansion/contraction of the soil even below frost line.

 

[varmint]

Thanks, Eddie. I didn't know this, but it makes perfect sense. I woulda used poly, but your point about stretch (and shrinkage) is true!

 

[Grn mtn boy]

SDR does not mean sewer and drain. It stands for Standard Dimension Ratio. I've put a lot of SDR in the ground. My current house has about 600 ft of 1-1/2 inch with 100psi + on it with no problems. I live in northern Vermont where it gets plenty cold. Pipe should be buried below frost line for obvious reasons. It's not going to blow apart if installed correctly. Place thrust blocks behind any bends to distribute the force created into the compacted soil behind it.
Gasketed pipe with go together much faster than glue joints. Another thing to consider is the solvents needed for glue joints.... You're going to be drinking that water. Gaskets pipe uses a soap lubricant that's potable.

 

[EddieWalker]

SDR does not mean sewer and drain. It stands for Standard Dimension Ratio.

Thanks. I looked this up and saw that I was wrong. The utility companies that I've worked with all call it sewer drain pipe, so I assumed that's what SDR was short for. I've installed some of it for drain lines, but since they are usually pretty short, I usually use Schedule 40

For water lines, I've used both Schedule 40 and C 900. The big deciding factor is distance. For long runs, the gaskets allow movement in the ground. Going deep doesn't eliminate all the movement, but it helps. Black Poly will still fail. I realize that some people will go their whole life without failure, but I also know that in the grand scheme of things, black poly is more prone to failure then just about anything else.

Eddie

 

[nrc17gto]

Sorry I should have mentioned I am going to be using 2". Water company wants it 24" deep here in Tn. The sdr that was recommended is a gasketed pipe for up to 200 psi. Here is a lowes example. http://www.lowes.com/pd_23993-1814-...22012+4294931368_4294937087?productId=3133107

From what I have read so far my main concern of the sdr-21 is it is not as thick as schedule 40.

Thanks for the input.
Nick

 

[TheGoose]

I've seen PVC break, but never at the bell ends. I would go with sch 40 pvc (which has a pressure rating of about 400 psig depending on size). Use the RIGHT type of glue and be sure to use primer.

Eddie, I have also dug up and repaired a lot of black poly pipe through the years but I learned that in some places they can get much better quality poly than we can get here in Tx. Most of the stuff buried here is rated for 80 psig but up north they can get 160 or 200 psi rated poly which is much tougher and is recommended by a lot of folks. No joints except at the ends.