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tsunami_gw

How to pressure test pool lines?

tsunami
15 years ago

We're a couple of weeks away from pouring the deck, and I'd like to pressure test the lines. It's been a while(couple of months) since it was first tested and past inspection, and there's been a lot of foot traffic since.

All the plumbing is still set-up for testing, except for the waterfall line which was cut to fit during it's construction, and the auto-fill line was moved to a different source.

If I have to, I could call the PB to have someone come out, but I'd like to start back filling this weekend instead of waiting a couple of days for them to show.

I noticed that above the pressure gauge there's a spigot, and at the gauge, there's an air valve. I thought that the test was done with water, but why would there be an air valve? I'm starting to think that the test is done with air instead of water, like the gas lines are tested with air instead of gas.

Could I just cap-off the waterfall line and fill the system with air? How many pounds for how many minutes? Would that cover the auto-fill line as well. The auto-fill source is tapped off of the sprinkler system and that valve is in the closed position(off). After the closed valve is the anti-siphon followed by another valve in the open position(on).

Thanks, John

Comments (30)

  • chulaman
    15 years ago

    You just need a double male adapter and hook a garden hose to the spigot. When the pressure builds up to about 40lbs turn off the spigot and then turn off the water.

  • frodo_2009
    15 years ago

    as chulaman suggested, fill the lines with water
    then...fill with compressed air.
    what is the type of gauge? what is the range?
    i gauge should never be maxed out..if its a 0-150 psi gauge
    fill with air to 100 psi
    if filled to max..it will not give an accurate reading
    using pressurised water and air is called hydrostatic
    testing...also..look on the piping itself.it has writting on the piping. it will tell the max pressure rating for the pipe

  • poolguynj
    15 years ago

    I have NEVER seen a need to go beyond 25 p.s.i..

    If a pool's equipment is involved, you can't go beyond it's rating of 50 p.s.i. and even that can be problematic for some parts.

  • huskyridor
    15 years ago

    I utilize water and a nitrogen tank to perform a pressure test. My pressure is at 30-35 psi.
    Chulaman is correct, you can test with only water by utilizing a washing machine supply hose.
    25-30 psi is plenty of pressure for this test.
    You'll need to place a cap on the waterfall pipe, add water and cap it when you see it approaching the top of the pipe. The fill line will have to be tested by itself because its not part of the pools circulatory plumbing.
    If your pressure is very slowly going down watch the main drains and skimmers, they're probably leeching a little water past the pipe dope on the threads of the male plugs.
    This is normal if your plugs aren't threaded in very tightly.

    See ya,
    Kelly

  • tsunami
    Original Author
    15 years ago

    Thanks for all the help everyone. I've been so busy that I haven't had the chance to try anything yet. I hope I have some time to do it tomorrow.

    Right now it looks like I'll be doing the test with air since I don't have the connections to do it with water.

    Kelly, I'm guessing that you use nitrogen to avoid the fluctuation that you might get with air?

  • tsunami
    Original Author
    15 years ago

    Today, I finally got around to capping off the waterfall line and pressurized the line. It's a 30 lb gauge, so I filled it to 27 lbs.

    15 minutes later, it was at 25 and 3/4 lbs. It lost 1 and 1/4 lbs in just that short time.

    I'm hoping that it's the test gauge fixture on the threaded parts on the manifold. It's galvanized piping that doesn't seem to have teflon tape or joint compound on some of the connections. There's also a gate valve with a spigot on top. The whole fixture looks aged. Tomorrow, I'll spray a soapy solution on the threaded connections.

    I hope it's not the threaded connection on the waterfall line that I capped off. I used joint compound for PVC pipe, but it was a tight spot to get to.

  • tsunami
    Original Author
    15 years ago

    I forgot to mention that I ran the test with air only.

  • Rack Etear
    15 years ago

    You can fill the main drains and skimmers up with water and check for bubbling on an air test. I prefer to test with water whenever the temperatures are above freezing. The reason is two-fold one because you can see water leaking out of places, and 2 when a pipe is under an air test it can be explosive because the air wants to expand. About 5 years ago I hit a 6" pipe with a pick axe while trenching in a new line, and it got dark really fast. One of the other guys on the job site said the dirt went 30 feet in the air, and the plastic chunks of the pipe went even higher.

  • rossterman
    15 years ago

    The other advantage of using water is the pressure drop will be more noticable if a leak occurs since water doesn't compress. Suggest a quick trip to home depot to buy the washing machine hose (cheap rubber ones are ~ $5) and test at no more than 50psi. Pressure may fluctuate a few pounds up or down because of weather changes but shouldn't drop over a couple of days. If is does, you have a leak somewhere.

  • tsunami
    Original Author
    15 years ago

    The following day the gauge read 3 and 1/2 lbs. There was a serious leak. I first checked the plug that I put on the waterfall by filling the tank with water and found bubbles coming out from around the cap.

    I released the pressure, removed the cap, and removed some of the sealant around the threads. I guess I over did it and put on too much joint compound. But I think the cap wasn't on tight enough.

    I capped it off and again filled it with air to 16 lbs(I ran out of air). It held steady at 16 five hours later. I later filled it to 28 lbs. It went down slightly after an hour. I'll check it again tomorrow.

    I got a double hose fitting from HD but still haven't tested it with water because I think there's water already in the lines since I could hear gurgling in the manifold when the cap was leaking.

    If I do fill the lines with water and the PB comes to install the equipment, how do they get the water out of the lines to cut the manifold in the clear and make their connections to the equipment? How do they prevent having a muddy mess right there at the equipment pad?

  • Rack Etear
    15 years ago

    "If I do fill the lines with water and the PB comes to install the equipment, how do they get the water out of the lines to cut the manifold in the clear and make their connections to the equipment? How do they prevent having a muddy mess right there at the equipment pad?"

    By being tough. If you can't get wet or dirty, you shoudlnt be building pools.

    But if the equipment sits higher than the pool, you can cut the pipes in the pool so they drain into the pool.

  • tsunami
    Original Author
    15 years ago

    "By being tough. If you can't get wet or dirty, you shoudlnt be building pools. "

    :)

    "But if the equipment sits higher than the pool, you can cut the pipes in the pool so they drain into the pool."

    That definitely sounds like the way to go.

  • huskyridor
    15 years ago

    quote" By being tough. If you can't get wet or dirty, you shouldn't be building pools. "quote

    !!!ROTFLMAO!!!

    Tsunami, you can use a shop vac to blow the water out of the pipes, remove the plugs, cut off the pipe caps, then blow from the other end.

    See ya,
    Kelly

  • tsunami
    Original Author
    15 years ago

    30 hours after filling it to 28 lbs, it was at 18 and 1/2. I've been too busy to do anything else.

  • poolguynj
    15 years ago

    Spray soapy water in the fittings and valves. Use Ivory dish soap and water. Look for bubbles after pressurizing again.

    I hope you didn't fill the trenches yet.

  • tsunami
    Original Author
    15 years ago

    It's down to 15 lbs today. There's about 3 to 6 inches of dirt covering the pipes from the manifold to 25 feet away.

    I did my own testing to see for myself if there could be a problem. When the test was first done by the PB, I watched (but didn't document) the pressure slowly go down. I let the PB know and they didn't seem too concerned about it. He said that they would know if a connection was leaking.

    But that's not good enough for me. I'm not about to take a chance spending around 10K on the hardscape only to have it dug up because of a leak. I'm going to have them take a look at it.

  • Rack Etear
    15 years ago

    I agree with what you are saying 100%..

  • tsunami
    Original Author
    15 years ago

    The job foreman stopped and I voiced my concerns. He pressurize the lines for me. He uses water to pressurize it.

    huskyridor, he used a washing machine hose to fill it.

    The gauge goes up to 30 lbs. He filled it to 20. He later noticed that the air valve was leaking! I'm hoping that that's where the leak is. He put a cap on it for now to see if that would help. It didn't. Today it went down to 18.5 lbs.

    I'm going to spray soapy solution on it, and replace it if it's leaking, then try again.

  • tsunami
    Original Author
    15 years ago

    Since the schrader valve was leaking, I released the pressure by draining the lines with a garden hose. It took a while for the water to drain. I removed the valve to check its condition. It looked OK but there was some rust on it. I didn't have a spare so I lubed the o-ring with silicone grease and reinstalled it.

    The gauge is made by BIL and only goes up to 30 lbs. Out of curiosity I filled it with water to 30 lbs. It held for a day then went down to 29.5 the next. I thought everything was OK until a couple days later it was down to 28.

    I searched the manifold for leaks, looked for wet spots on the ground, then I went to the pool where I saw that the gunite was all wet below the skimmer. Water was coming out of the skimmer and into the pool.

    I thought I remember someone saying that the skimmer would only hold about 22 lbs of pressure before the weir would open. Does that sound right? So anyway, I dropped the pressure down to 21 lbs and the water stopped coming out of the skimmer and the pressure has since held fluctuating plus or minus half a lb. and it's been 3 days now.

  • poolguynj
    15 years ago

    Sounds good to go! I rarely go beyond 20 PSI when I test but that is usually on existing pools, not on new construction where the use of glued on pipe caps holds more pressure. Threaded fittings can leak, such as those found on the bottom of a skimmer or a liner pool's returns.

    WRT to the check valve spring, stainless comes in different grades. Manufacturers choose for both it's physical characteristics and cost. Springs need flexibility. The higher grades are too stiff or brittle to last. The lower grades are less resistant to oxidation. That's why you see a little rust on on some stainless.

    Check valves also have gaskets that wear out too, usually before the spring wears out. Expect to change the flapper periodically. I can't say when so you mileage may vary.

  • huskyridor
    15 years ago

    Everything is fine on your pressure test.
    The slight pressure you lost was past the threads was on the cleanout plug threads into the port in your skimmer.
    This is normal. Water under pressure has energy and pushes past the pipe dope on the male threads.

    See ya,
    Kelly

  • tsunami
    Original Author
    15 years ago

    That's a relief! I was hoping that 20 lbs was enough. Actually, now it's at 20.5 and I noticed a little water coming out from the skimmer again. I also noticed some gunite or mortar in there. I'm gonna have to clean it out.

  • bberger
    14 years ago

    Well........I know this is an old thread but after reading it, I'm kind of nervous. I've just done a LOT of plumbing and I did not pressure test. I've already encased the skimmer in concrete and buried the pipes (pretty shallow though). I was very careful gluing and taped any threads that I had. I'll be shocked if I have a leak. I have a 6' sheer descent that I dry fit the last joint because I haven't set it's final position. It barely leaked on that joint when I ran it. I hope I'm not overconfident. Keep your fingers crossed.

  • tsunami
    Original Author
    14 years ago

    Maybe you could still cap the lines and pressure test for peace of mind? My experience has been that the threaded connections are the ones that's more likely to leak.

  • bberger
    14 years ago

    Hey tsunami.....you couldn't be more right. 5 threaded connections - 4 leaks. Pump input - no problem, I used unions. The other 3 were small leaks but had to be fixed. I had no room to cut and tighten so I purple primed the groove between the male and female fittings and used epoxy putty. It worked great! Saved several hours of work and a couple of jandy check valves. I was unable to plug the skimmer (new) or the spa drain (old) without leaks. At 40psi I didn't see any other seepage. I'm satisfied that I don't have any other leaks. The new skimmer has a slip joint on the bottom. I'm sure glad I did this check. I'm close to having the pool replastered and I didn't want to chase these leaks down then. So for future reference, Am I doing something wrong with the threads? I'm using teflon tape. Thanks, Bruce

  • tsunami
    Original Author
    14 years ago

    "Am I doing something wrong with the threads? I'm using teflon tape."

    Ask 3 different plumbers, and you'll get 3 different answers. First, my disclaimer: I'm not a plumber, but I did spend a year in the trade as a pipe fitter many years ago. Ever since then I've been doing my own plumbing for myself and the family. I haven't done any pools nor do I plan to.

    With threaded PVC joints, if you tighten them too much they could break. I've used both teflon tape and joint compounds and so far have found no advantage of one over another. Too much or too little of either one sometimes ends up in a leak. On your typical male to female threaded joint, what's been working for me lately is 4 to 6 layers of teflon tape topped with a light layer of silicone lube on the male end only. With the lube I can tighten the joint more without breaking it. There's a silicone based lube called "Magic Lube" that you might want to try. You can find it at you local pool store.

    To me the unions are the most likely to leak of the threaded joints. If the pipes are just a slight bit out of alignment or a little too far apart, you could have a leak. Square cuts and accurate lengths are important. I've been using a chop saw to make my cuts, and it works great. I highly recommend it if you have one. You may also want to coat the teflon tape with "Magic Lube" on the PVC union. Also, there's another sealant made for PVC unions called "Permatex", but I haven't tried it yet. You'll find both on the link below.

    Here is a link that might be useful: Pool Sealants & Pool Lubricants

  • bberger
    14 years ago

    Thanks again. My plumbing is done and I did use a chop saw. 3 pumps (waterfall, sheer descent, and pool/spa) THAT was a lot of cutting. The saw was a godsend. Unions are fine. I lubed the o-rings a little before I connected them.

  • tsunami
    Original Author
    14 years ago

    I admire you for doing the job yourself, because that's definitely alot of work for a DIY'er. Did you have any help?

  • bberger
    14 years ago

    No help but I'm retired so I have the time and I enjoy doing it.