Under ground water lines, best practice for joints and fittings

[HeLa]

i did a good bit of research on this last year.

fusion is best practice. and everything i read suggested that this should be done by an experienced professional. set up all your joints, call someone in, cost should be reasonable.

that said - i went with barbs and clamps because i was doing the work a little at a time and it wasn't practical to call someone in (or even rent the tool) each time.

if you go with barbed fittings, a few tips from my experience:

1. i used heavy poly (250 psi ?) warmed in hot water or sun (avoided a heat gun for fear of warping plastic) and tapped the barbs in with rubber mallet where possible
2. lead-free brass fittings with extra long barbs
3. double clamped every barb with stainless oetiker clamps. (don't waste your time/money with the screwclamp junk)
4. spend a few extra bucks on the oetiker crimp tool that can grab the ears parallel or perpendicular​

 

[Midniteoyl]

Pipe is a good grade of black poly. Directional bore was about 150 feet mostly up hill and under some established landscaping, a side walk, and a 10' deep front porch. Depth was maintained at +- 6' and the emerging end of the drill came with in inches of the desired target in the house crawl space. Amazing technology.

B. John

For poly, simply use barbed fittings with Oetiker type clamps..Double the clamps for buried connections. Heat the pipe slightly before sliding onto the barbs, and just before you tighten the clamps and you will never have a problem. Dont over heat though as 99% of problems/leaking come from over heating and thinning the poly.

This is the simplest most secure way.

 

[newbury]

For poly, simply use barbed fittings with Oetiker type clamps..Double the clamps for buried connections. Heat the pipe slightly before sliding onto the barbs, and just before you tighten the clamps and you will never have a problem. Dont over heat though as 99% of problems/leaking come from over heating and thinning the poly.

This is the simplest most secure way.

Which oetiker clamp?

 

[Midniteoyl]

Which oetiker clamp?
View attachment 476887

The Ear clamps.. Typically called an Oetiker: Oetiker clamp - Google Search

Doesnt have to be that brand

 

[greenmojo]

My 2 cents...

I had a discussion about 100 psi poly and 200 psi poly fittings for all of my runs on the property with the guys down at the local irrigation supply house (central Washington, lots to irrigate).

I have about 1500' of 1" poly run about the property as I am pushing nature back and it is a mix of 100 psi and 200 psi. I have the more expensive compression fittings on the 200 psi and used barb fittings on the 100 psi.

In the end, they said barbed fittings for 100 psi poly should always be double clamped, and they recommend the eared / crimped clamp. The earth does a great job of immobilizing connections and it has been done this way for a long time. For 200 psi poly, I used the more expensive compression fittings and although it is suppose to be a better solution, we had more leaks and had to "muscle" the fittings down with a wrench to really get a good seal.

In the future, I just didn't see the benefit of 200 psi poly and fittings that cost $70 to $120 each... I'll end up with the rest of the runs using 100 psi poly and barb fittings slightly heated.

~Moses

 

[HeLa]

right, oetiker is a brand but the type you are looking for can also be called 'pinch' or 'ear' clamps.

they come in single- and double-pinch styles. as you pinch the "ear" you close the clamp up. the double-pinch styles accommodate a larger range of diameter and are generally suggested for thicker wall tubing but can require access to the clamp from two sides (not always so easy in a ditch). just make sure you buy them in stainless.

here is the single-pinch:

no moving parts. little chance of failure. use two on each barb.

McMaster has a good variety in stainless:

McMaster-Carr

 

[greenmojo]

right, oetiker is a brand but the type you are looking for can also be called 'pinch' or 'ear' clamps.

they come in single- and double-pinch styles. as you pinch the "ear" you close the clamp up. the double-pinch styles accommodate a larger range of diameter and are generally suggested for thicker wall tubing but can require access to the clamp from two sides (not always so easy in a ditch). just make sure you buy them in stainless.

here is the single-pinch:

no moving parts. little chance of failure. use two on each barb.

McMaster has a good variety in stainless:

McMaster-Carr

+1

This is what we used for our 1" and 2" barbed connections.

~Moses

 

[HeLa]

My 2 cents...

I used the more expensive compression fittings and although it is suppose to be a better solution, we had more leaks and had to "muscle" the fittings down with a wrench to really get a good seal.

In the future, I just didn't see the benefit of 200 psi poly and fittings that cost $70 to $120 each.

~Moses

thanks, good info re: the fittings! properly set and clamped barbs should last a long while.

i went with the thicker (low SDR) tubing in hopes of having a bit more abrasion resistance in case of shifting. a few extra bucks for sure but i'm hoping never to dig this job up again.

thicker tubing is also why i went with the double-pinch clamps. it allowed me to apply pressure from two sides and theoretically compress the tubing more evenly onto the barb.

 

[Kenneth in Texas]

sounds stupid i know but what was the reason not to use just plain old schedule 40 pvc?

 

[Midniteoyl]

sounds stupid i know but what was the reason not to use just plain old schedule 40 pvc?

Easier to bore drill with, and PVC can crack when buried.. Poly is usually the way to go now a days