Best way to join Poly pipe, for a water pipe repair.
So I sprung a water leak in my main water line. After hours and hours of troubleshooting, searching, and random digging I finally found the culprit. It was an area that was patched by a previous owner and failed.
Now I'm pretty sure from what I've heard at the hardware store, the pipe is "poly" pipe. Its the black plastic kind. I'm pretty sure the inside diameter is 1" although I haven't cut it open yet. Upon further research I see there is polyethylene and also high density polyethylene. How do I know the difference?
The way it was patched before is they put a new 2 foot section in, with two barbed couplers, one on each end. The barbs were tightened down with two hose clamps on each pipe end (so a total of 4 hose clamps per barbed coupler). This is the same method the lady at the hardware store said to connect them with.
Well the leak right now is on one of those couplers. Interestingly enough, its not actually leaking from imbetween the barb and pipe, but rather the pipe got some small holes in the pipe itself where the clamp was touching. One main hole right along the outside edge of the clamp, and one hole that was underneath the clamp when I loosened it a bit (I shoved a piece of rubber in the hose clamp and re-tightened it to temporarily fix it).
Does anyone know why it would develop holes under the clamp? Perhaps it was tightened too tight or something?
Anywyas, onto the most important part of my question. I'm wondering if there is a stronger, more reliable way to connect a new patch in there rather than barbed connectors?
I want to chop out the whole 2 foot repaired section, and replace it with a new, slightly bigger section. But I want to fix it the right way this time and make a repair that will hopefully outlast the rest of the pipe.
I've searched all over the web but just can't find any details on joining it. I heard a couple of tidbits about heat welding, but it apparently needed an expensive machine or something, couldn't find any details on how an average diy'er could heat weld it.
I'm really hoping there is some way better than barbed connectors. But if that's my only real choice of something that can easily be done myself, could anyone give me some advice as to the best way to do it? Such as, what type of barb couplers (the hardware store had both metal, and plastic ones), how many hose clamps to use, and how tight to make them? And if there are any extra little steps, or ways to go above and beyond, like perhaps some sort of cement that can be used also, or padding the hose clamps with some sort of material (since like I said, the leak now seems like it may have been caused by a hose clamp), or some other tips.
One on the best ways to connect poly pipe is to use the barbed poly fittings. I would go with the steel fittings. The connections have to be with pipe that is cut square at 90 deg. Don't cut the pipe short, make sure that the pipe gets right to the rings of the fitting.
You will have to heat the poly up to get it warm to expand very slightly to insert the (poly or steel) fittings. This is where the previous owner might have had a problem. If the poly is heated too fast or too much, it will melt and could cause the pipe to have holes. Sometime if the fitting is forced on, or hammered on when the pipe is cold it could have split the pipe. Make sure that the fittings are on the pipe before you heat it or put the fitting in the pipe.
I like to use a heavy duty hair dryer at 1500 - 1800 watts. If you are really careful, you can try a soldering torch with a flame spreader. Be careful, and go slow. You might also want to practice before the actual job. It's a pain in the butt to get to the fourth heat-up and then melt the pipe.
I don't like the worm gear type of hose clamps. You can't get them really tight. I like to use an 'Oetiker' clamp. It's a stainless steel pinch ring (ear). In over eight years of irrigation installations, I haven't had one come open or apart yet. The box stores won't have them, but the plumbing supply houses will. A really good old fashioned hardware store might have them also. You might have to purchase an Oetiker tool, or use a nipper type tool that has had the 'nippers' blunted so that you don't cut the clamp.
Sorry I don't have information on repair because I only use K
copper underground with no joints.( If Possible)
What I will add is once you make the repair don't ever backfill the joints, install boxes so you can always see the joints, Just In Case.
A main water supply is differnet than an irrigation system.
If the pipe is thin-wall poly (irrigation pipe) then your only option is the barbed fittings.
If the pipe is thick wall municipal tubing, you have more options. You can use compression couplings (we typically use the brass "quick joint" compression by compression couplings for repairs, listed on pg. J4 in the link below. Don't forget the stiffener inserts).
I`ve seen contractors and homeowners around town using the new Sharkbite fittings as well, but have no personal experience when them.
Water Line Repair
Of course the best solution is to replace the whole line however that's not usually practical. I have spliced many water lines between the meter and the house.
We use brass or stainless steel insert fittings and a good 200 psi polyethylene pipe and all stainless steel clamps (not usually available at big box stores). Purchase from a quality plumbing or pump supplier warehouse if possible!
Note: As one person stated you may need to warm the poly pipe ends with a heat gun or hair dryer carefully to insert the fittings.
The pipe must go all the way to the shoulder stop. Install the s.s. clamps directly over the barbs using two clamps on each ends of the inserts tightning screws opposing each other.
If possible after turning on the water again, let the spliced section set over night, then retightning the clamps again before covering the line up.
Porky Cutter, MGWC
Master Ground Water Consultant
Thanks for all the help. I'm about to shut off the water, chop off the pipe, and go down to buy the metal couplers, extra pipe, and the best hose clamps I can find (either the oetiker or all stainless if I can find them). I have a couple last questions.
1. About how much do I want to heat the pipe? Just the minimum amount to get the fitting in, or a little more? I do have an infared thermometer to check temps, and my heat gun if i remember right is variable up to 1500 watts.
2. Do I want to wait for it to fully cool before applying pressure to the clamps, or is it good to clamp them when its warm? It seems like doing it while warm might help it clamp tighter, however at the same time it seems like there could be a risk of compromizing the pipe by squishing it too hard with the clamp when its warm?
3. I'm planning on practicing the barb insertion on a scrap first. If for some reason I find the barb does slide in with a nice tight fit, without heat, should I still heat anyways?
4. How do I know how tight to make the clamps? Is there a risk of overtightening? (afterall the last leak sprung from where the clamp was (the farthest clamp from the actual joint).
4. Also for some reason, the last repaired sections seemed to have been spray painted white. Any reason for this, and is it possible that chemicals in the paint could have eaten the pipe causing the leak?
Thanks for all the help.
Thanks Sultini, with only eight years of installing potable water lines and irrigation systems for a living, it helps to know that, "A main water supply is differnet than an irrigation system." I know there is a difference; I only said that, that is the installation and repair parts that I use. Don't criticize someone's poly repair information If the first thing that you say is, "Sorry I don't have information on repair because I only use K
copper underground with no joints.( If Possible)"
If you do the repair properly it will last for the life of the pipe. Watch it for a day or two. If it's good for that long, you don't need to 'box' it. If you don't know what you are doing, do what Santini does and box it.
I forgot to post this before, the PSI of the pipe will be marked on the exterior of the pipe. In most cases you should be able to read it to match the pipe. This doesn't help with the white paint.
Around here poly water supply is rated as "Municipal" pipe. Check with your local inspectors.
Heat the pipe to just enough to slip the fitting in. You can tighten the fitting while still warm. If you squish the pipe, then you are too hot. With the proper size Oetiker clamp, you won't be able to over tighten. With a worm/hose clamp, it will pop before you can do any damage, unless you are too hot. Sorry, don't know temperatures, I have been taught and go by what 'feels' good. Heat evenly, and take your time.
If you are shutting off the water, take a section of good pipe with you for new purchase and match-up.
The only thing that I can think of with white paint on the pipe is that it was salvaged pipe from somewhere else. Paint shouldn't affect the exterior of the pipe, but it might cause a problem with heating the pipe.
Let us know how it turned out and what you used.
Well I just finished the job. I used brass couplers, and stainless steel worm clamps (couldn't find the other special clamps). I really took my time heating the pipe, probably much longer than I had to, but wanted to be safe. It seems like right around 200 degrees was what it took. That's the surface temperature at least that was measured, perhaps the pipe as a whole was a bit less. That was just barely enough, it still took a lot of effort to push them on at that temp (partly because of the awkwardness of reaching over 2 feet down in a narrow trench. I used 200psi pipe for the repair, apparently by the measurements my old pipe is 160psi, I figured I might as well go for the best. The 200psi is rougly .03" thicker, so I figure whatever little bit helps to avoid pinholes like the last one.
Anyways, no leaks so far. I plan to wait a couple days, give one last tighten on the clamps, and then fill it up. I really appreciate all the help guys, I feel confident that its a good job. Glad you recommended the warming of the pipe. The clerk at the hardware store (while seeming mostly knowledgeable in every other sence), claimed the way to get them in is to just hammer them in. Glad I knew to warm it up instead.
Thanks for the help.
a little rector seal on the ends of pipe nipple helps it go in easier also without overheating the pipe :thumbsup:
Shark Bite does not work on poly pipe
Thanks for the great advice on heating up the old Poly
I had a leak in my old Poly water main line going to my house. I thought I was hosed because the poly fittings I was using kept splitting my pipe. I used my wifes hair dryer and bought steel fittings and redid the repair and have no issues!
Thanks you guys!!
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