underground tank testing

Plug the vents, drill hole in tank cap insert automotive type tire valve stem and introduce and inert gas to approximately 3-5 psi then check pressure occasionally.

(Plug the vents, drill hole in tank cap insert automotive type tire valve stem and introduce and inert gas to approximately 3-5 psi then check pressure occasionally) ????

I hope you wrote this as a joke. Testing a tank this way is unreliable and dangerous.

do the math yourself, a 10,000 gall tank presurised to 2 psi, remove .01 gall liquid from a hole in the bottom and the gauge should move approx 0.000002psi. depending on the volume of stored liquid. assuming there is zero temperature change(which is unlikely)

The original post was after information from trained professionals

posting unreliable information such as this is dangerous.

I have only replied as a courtesy to anyone silly enough to try your method to not do it.

The type testing equipment needed is specified by the state and or country in which the tank is situated and that type equipment is needed because safety is paramount. This a silly answer too.

Having worked in the fuel industry in the 70,s and 80,s the accepted practice back then was to plug all the outlets Vent pipes dip lines etc on the tank and under the pump, take a reading on the dip stick and pump the tank up to approx 15 psi, leave the tank for 15 minutes check the dial for pressure drop open vent line and take a reading from the dipstick loss product = leaking tank pipework to pump etc. Wasnt very enviromentally friendly though. I am not up to date with how they test the tanks now but plugging all outlets and applying a small vacumn will draw water etc into tank and loss of vacumn would indicate a leak. Water paste on dip stick before and after test would be your indicator for tank making water.

sometime in the 80's pressurizing an underground fuel tanks above 2-3 psi was banned, due to many things including risk of rupture, explosion, failing to find leaks etc. (probably also as cowboy contractors were calling this a tank test)

If it was as easy as checking the dip stick with some water paste anyone could do it.

I wish to purchase equipment to leak test underground fuel tanks, there are many systems out there.

Anyone suggesting to merely plug the vent and check the guage and the dipstick does not have a technical understanding of what is required.

just to clarify, the tank is currently in service? or are you asking about testing at the manufacturer's site prior to placement?

just to clarify, the tank is currently in service? or are you asking about testing at the manufacturer's site prior to placement?

Yes currently installed and in service. To certify integrity ie: not leaking.

The test at the manufacturers is not an option and usually relies on pressure and soapy water

I think I am being punked I'll just go and check for hidden cameras.

No cameras,

I will continue as a courtesy to any one interested, or wishing to know a small bit about underground tank testing.

Tanks have not changed significantly, and do not usually have bulk heads.

they are made of steel\fibreglass or both and double walled(which dont need testing)

I repeat in regard to close to #1

Anyone who thinks they can test a buried tank with a pressure guage and a dip stick is wrong and does not know what they are talking about. apart from very small tank volumnes measured over extended timeframes

With the exception of Masstech which is more involved than a pressure guage and must account for atmospheric changes during the test.

The test has to compensate for temperature change in 1\1000th of a degree,(unless measuring mass) and level changes in 1\1000 of an inch .

Vacumn tests use a hydro phone and a micro phone but have trouble hearing water entry if the hole is below liquid level. This is also not really a volumetric test.

You cannot measure an ingress of .01 of a us gal\hr with a dip stick. similarly with an egress.

Please lord help me to keep my big mouth shut until I know what I am talking about.

This should be said 3 times before every posting.