PEX leak question


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Old 02-19-21, 11:04 AM
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PEX leak question

Water leaks inside the valve box. Leaking, not gushing out. 1" white PEX with black crimp rings. I cannot get to the leak without some digging but it appears to be the last PEX fitting (ell) before a straight run to the house.

Q1. I will check the crimp rings with go/no-go gauge. If not fully crimped, can I just recrimp it? Or would you rather replace the crimp ring?

Q2. Can I use either PEX A or B? Or is A to be expanded and B to be crimp ring-ed?

fiy: Age of the parts (when the repair was made) unknown.

Thank you.
 
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Old 02-19-21, 12:18 PM
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I have never had a properly crimped PEX connection leak. You can bring your crimpers but I doubt a weak crimp is the culprit. I have had several brass fittings corrode through and fail so my guess is you will need a new fitting.

Make sure no light can get into your valve box. Most versions of PEX are NOT UV protected and exposure to UV can make it brittle and cause failure.
 
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Old 02-19-21, 01:00 PM
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I agree, I've never seen a proper crimped connection fail. If you're in freezing areas, it's possible the fitting split. PEX is pretty flexible for freezing, but the fittings don't have any give to them.
 
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Old 02-19-21, 07:15 PM
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Thank you. I will replace the fitting. I will also place an extra light cover just in case. The valve box didn't freeze.

Regarding PEX fitting corrosion, is it brand specific? My toilet feeder line froze in this week's cold (single digit in Texas). Would you recommend against PEX? Original line is 1/2 in copper, temporarily capped for now. Thank you.

By the way I saw plastic pex connectors at Home Depot. Would you recommend it over brass pex fitting?
 
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Old 02-20-21, 10:18 AM
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Stick with PEX it's the most resistant to freeze damage.
 
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Old 02-23-21, 09:56 AM
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Thank you for the advice. After some more digging, I found the culprit. The coupling between copper (house side) and pex (street side) leaks on the copper side. The solder failed.

Question is how to fix this. Initially plumber suggested all copper. I said ok. Now the plumber wants to use a sharkbite fitting instead of soldering. His reason is the joint is the lowest point of the house plumbing and will not stay dry for soldering. His explanation makes sense. But I am concerned about an O-ring separating drinking water from muddy water. What is your advice on Sharbite underground (and underwater during rainy season)? Thank you.
 
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Old 02-23-21, 11:45 AM
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I don't fully trust a single O ring either but, they are approved. My biggest issue with "bite" style fittings is I've had more than a few leak when there was stress, bending or a side load applied to the fitting. In many cases these leaks didn't appear until well after installation. So, in my mind they are OK for emergency use and repairs in exposed areas.

As for keeping potable and ground water separated I don't think that's an issue. The water in the pipe is under pretty decent pressure so any leakage is from the inside out.
 
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Old 02-24-21, 11:30 AM
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Thank you. I will avoid the bite type fitting. The leaky solder joint was installed 3 years ago, apparently inadequate soldering because the pipe didn't get completely dry, being the lowest point of the house water plumbing.

I have a related question. After shutting off the water main at the street, if I open the 1" water pipe (below ground level, lowest point of water plumbing), how long will water trickle down? Would a day be sufficient? Can I accelerate the process by blowing compressed air from kitchen, for instance? The goal is to keep the solder joint dry while soldering. Thank you.
 
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Old 02-24-21, 11:36 AM
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A day would be way more than sufficient to drain the pipe. It will go even faster if you open a faucet in the house. 10 or 15 minutes is the longest I've had one take to drain. When the water does stop flowing give it another couple minutes just to make sure there isn't another blob of water coming for a sneak attack.

If that isn't convenient I've frozen pipes with dry ice. Move back a couple feet from where you need to solder and pack dry ice around the pipe and hold it in place with old towels. Then after 15 minutes there should be a solid ice plug and you can work on the end without all the water back flowing.
 
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Old 03-10-21, 06:43 PM
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Thanks to your advice, the leak is fixed now. I had no choice but to use a sharkbite (push to connect) coupling to connect 1" PEX to 1" copper. I wrapped it with silicone tape as Sharkbite recommends. One final question. Can I fill the dug area with sand? Natural soil is clay with rocks. Thank you.
 
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Old 03-11-21, 05:50 AM
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I don't know why you couldn't use sand at least around the pipe for protection. Then use soil for the uppermost part of the hole so the grass will grow back.
 
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Old 03-11-21, 09:10 AM
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I was able to complete this project thanks to your advice.
 
 

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