leak testing fresh water

[Sevo]

Ok this may be a dumb question but I am really confused???

Everyone says to pressurize the fresh water tanks to see if they leak. Are you doing this because the fresh water tanks are under pressure? Why are you wanting to pressurize the fresh water tanks. I didn't think they would be pressurized as you have to vent them??

Any insight is appreciated

thanks

Chris

[S. Heisley]

Chris, not all water tanks should be pressurized. It depends on the type you have. If the tank is meant to be hooked up to a hose with constant pressure from a water source, then, by all means, pressure test it by hooking it up to a constant source of water. But if it's a non-pressurized tank, you don't test it that way. A non-pressurized water tank is basically just a holding tank. If it's one that you just fill with water and then disconnect from the water source; then, you should just fill it with water and pump the water through the faucet and watch for leaks. If you pressurize a non-pressure water tank, you could/probably would ruin it.

[Shadow Catcher]

What Sharon said!
Most fresh water tanks vent to atmosphere or you would have them imploding as you pump the water out or going up or down in altitude. I did pressure test the city/shore water connection which is not connected to the tank and pump using compressed air and just seeing if it would maintain pressure. It did for a couple of days.

[48Rob]

Chris,

Some tanks are pressurized, pretty easy to test, just inspect all fittings and connections after putting water in and pressurizing.
The ones that are not pressurized, still need to be checked as they have fittings and connections.
The plumbing system, no matter if it is supplied from a pressurized tank, a gravity tank, or is drawn up and is itself pressurized by a pump, must also be inspected.

Rob

[Sevo]

Great replies! Thank you. It really helped

here is what I have. I will have a holding tank hooked up to gravity feed so this will be non pressurized, I will take the city hookup line and it after the holding tank pump. This will make the side of it pressurized? Am I right in my thinking??

Therefore, I will need to do a pressurized test after the pump and a non-pressurized test from the holding tank to the pump?

Thanks again for you time

Chris

[eamarquardt]

If you do not want to pressurize your tank then there are other methods also to check out for the leak like-

1. Helium Mass Spectrometer
2. Thermal Leak Detector

However, thermal leak detector is very effective method of finding a leak as compared to helium spectrometer.

You can also use hydrogen and a match to test tanks. It's not a as good as helium though as the helium atom (it's an inert gas) is actually smaller than a hydrogen molecule (two atoms of hydrogen versus one atom of helium). There are also other disadvantages of using hydrogen and a match.

You can also use methane (natural gas) and a match but this technique shares some of the disadvantages
of using hydrogen and a match.

Stick with water.

Hope this helps.

Cheers,

Gus

[CarlLaFong]

You can also use hydrogen and a match to test tanks.

Hope this helps.

Cheers,

Gus