Pressure test - Is this okay?

[JayRi]

They ran plumbing for my pool on Friday. They left the system pressurized at 50 psi. Today is Monday and I am looking at it holding at 46 psi now. Is this okay? Should I bring it up to the builder? It’s supposed to get inspected tomorrow.
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[Aquaman7]

Did they pressurize it with water or air?

 

[JayRi]

Did they pressurize it with water or air?

I have no idea. I just looked at it when they were done and took the picture.

 

[Aquaman7]

If it was air it will fluctuate with the temperature. However I’m not sure what is a normal fluctuation.

 

[x Wild Bill x]

I would say more than likely that is normal and fine. Both air and water expand and contract with temperature. More than likely it was warmer on Friday when the system was pressurized and the pressure has gone down to a reduction in temperature. Just keep an eye on it and so long as it doesn't continue to drop I would not be concerned (if it gets colder out then the pressure may drop a little more and if warms up the pressure may go back up). Also, if it was pressurized with air from an air compressor the air was most likely heated when compressed and once cooled caused the slight pressure drop.

 

[JoyfulNoise]

Pool plumbing is always pressurized with water, not air. They usually use your household water supply from a nearby spigot. Depending on where you live, inspector codes are different about what is considered a pass or fail in terms of pressure testing. Some building codes actually have a specification for how many PSI you can drop in a 1-hour and 24-hour period. Some municipalities have no code at all.

A 4 PSI drop would concern me but it could be residual air trapped in some low spot of the plumbing. I would ask the PB to depressurize the line and maybe do a few cycles of depressurizing the line and re-pressurizing the line (maybe swing between 25 and 50 psi for a few cycles) to try to get the water to move in the plumbing and dislodge any trapped air. Then watch it. I would expect the pressure to drop a bit with temperature and then stabilize. You can also spend some time in the trenches and at the equipment pad looking at the glue joints for any wet spots. A few handfuls of dry, fine powdery dirt sprinkled around the joints will easily show any leaks.

 

[Newdude]

A few handfuls of dry, fine powdery dirt sprinkled around the joints will easily show any leaks.

Or soapy water and look for bubbles.

 

[JayRi]

Thankds for the replies, I looked at it today, 2 days since the original post. It went down about 2-3 psi. Inspector is supposed to be out tomorrow.

 

[JoyfulNoise]

If you catch the inspector, you can ask him about it. I’ve heard of some places that have an exact value that your supposed set, like 32psi, and then you close the valve and wait 30mins. If there’s no change in pressure they declare it good. So the PB over pressurizes it and then the inspector sets it to where they want to see it.

Like I said, it varies a lot and so you’d have to ask the inspector what the code standard is.