How to pressure test pool lines?

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tsunami

tsunami

0
Sep 11, 2008
138
Oceanside, CA
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
 
Hey, John,

I am not too much help other than to tell you that the test is done with air. The Code will require a certain pressure to be established and that pressure to hold for a certain number of hours....I just don't know what those limits are.

My first choice would be to consult the builder but, lacking that, you could try about 30-35 psi (that's close to the max your pump can produce) and, if it held for 6 hours or so, I'd be pretty comfortable with it.

I would wait for someone else's input who would be more familiar with the requirements......what state are you in?
 
I have seen the test done both ways, with air and with water. Air pressure will vary with changes in temperature far more than water will. Large temperature changes, or changes in which equipment is in sunlight, can cause air to give misleading results. If you are aware of that issue then air can work well. Of course if freezing is likely you want to stay away from water.
 
I'm in SoCal. The foreman for my job is on vacation.

I watched the pressure gauge when the first test was done, but didn't write it down. I think I remember it being around 28-40 pounds, anyway, somewhere in that area. I remember it slowly going down over a few weeks, but not up, and don't remember how much, and I know it can fluctuate with temperature.

I brought up my concern to the foreman, and he said that he was confident that there were no connection leaks. He said that it would be obvious by watching the gauge. But I'd just like to do it again as a safety measure, since the decking is a big expense.

I'm just wondering if capping off that one line and filling with air would cover the whole system?
 
launboy said:
Capping off all open lines should seal it up.

Adam
Click to expand...

I was thinking that capping off that one line should take care of it, but I'm not familiar with skimmers and auto-fill plumbing and how they work. And I don't know if there's anything I have to do to the skimmer or auto-fill to get it to pressurize.
 
If the skimmers are open then the air can get out. There's n check valve or enything that would keep the air in. Not sure how the auto-fill is because I've never dealt with one. I supposed you could cap the waterfall line and hook the air up. You'll never get any pressure if something else is open.

Adam
 
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 with air 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.
 
launboy said:
Did the sun go down or the temp. change during this period of time? This can make a difference in the PSI.

Adam
Click to expand...

Actually, yes, I filled it about an hour before sundown. 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. 30 hours after filling it to 28 lbs, it was at 18 and 1/2. It's down to 15 lbs today.
 

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I hope I'm not too late but I have written quite a bit about my leak testing experience. Search my construction thread and you may find it.

In general, the whole system is filled and pressurized with water. Your readings will go up and down with the ambient temperature but it should NOT trend down AT ALL. Don't pour any concrete until you are 100% sure it's leak free. Don't let your builder tell you it's normal to have a small leak.

Good Luck,

Kevin
 
A few days later, the job foreman stopped by and I asked him if he could pressurize the lines for me.

Cobra, he used water to pressurize it. Using a hose for a washing machine, he filled the pipes with water til the pressure reached 20 lbs. The gauge goes up to 30lbs.

He noticed that the air valve was leaking! He put a cap on it to see if that would help. It didn't. The next day it was down to 18.5 lbs.

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 valve, 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.

Well, about a week later the pressure started to go down slowly again. Water was coming out from the skimmer again. I noticed a bunch of grout droppings in there. I'm going to clean it up to see if it helps. The pressure was down to 16 lbs the last I checked.
 
Tsunami,

Mine was pressurized to my full water pressure of 40 psi, which is on the low side of normal. The two lines in the skimmers were looped together creating a complete seal. The weirs are the little flapper things that were installed at the very end of construction. My pressure varied by about 5 psi with the normal temperature cycle of the day.

I would not trust the integrity of the system only pumping it to 20 psi.

Good Luck,

Kevin
 
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