Empty Tanks???

[Talerco]

I acquired several tanks with valves. I’m going to cut them to make garden gongs.
Some had valves that when opened drained air - for a long time. Those I now know are empty.
Others - especially the ones with smaller knobs - I’m not so sure about. When I turn the knob nothing happens but……
I don’t want to have a missle crashing into my neighbors house - or me!
How do I confirm if these are empty?
Can I drill a small hole in the bottom? What will happen if I do that to a full tank?
Thanks, David

 

[Still Kicking]

Remove the burst disk (small nut on valve). But if you turn the handle and nothing happened, 99.999% they are empty.

 

[davecampbell]

make sure you pull the levers on the j valves...

 

[OMyMyOHellYes]

A small hole in a full tank = rocket.

 

[iointerrupt]

Do not remove the burst disc without clamping the cylinder down. People have died doing otherwise: NIOSH LODD Report: Ohio Firefighter Dies after Being Struck by SCUBA Cylinder - FirefighterNation: Fire Rescue - Firefighting News and Community

A ratchet strap and a tree is a cheap way to hold a cylinder in place.

 

[johndiver999]

open the valve, put your lips on the valve and make a seal. then blow air in the tank. If air goes in, then the valve is open and the tank is empty.

 

[Still Kicking]

Do not remove the burst disc without clamping the cylinder down. People have died doing otherwise: NIOSH LODD Report: Ohio Firefighter Dies after Being Struck by SCUBA Cylinder - FirefighterNation: Fire Rescue - Firefighting News and Community

A ratchet strap and a tree is a cheap way to hold a cylinder in place.

Good point -- if you crack the burst disk and it starts hissing, then of course stop until the pressure is released. But securing the tank wouldn't hurt.

 

[NW Dive Dawg]

I have the luxury and privilege of living and owning plenty of acreage here in the PAC NW with my own ranges in place. After opening the valves fully, I would not take any chances on the valve and place the tank out at 200 yards and use my Springfield M1-A to put a few 308 / 7.62mm armor piercing FMJ rounds directly into the dead center of the bottom of the tank. Just to take any concerns of any remaining pressure out of the equation.

 

[Scared Silly]

open the valve, put your lips on the valve and make a seal. then blow air in the tank. If air goes in, then the valve is open and the tank is empty.

May sound odd, but one can put two values face-to-face and force gas into an empty cylinder. Open the empty cylinder, then open the full cylinder, close the empty cylinder, then close the full cylinder. This will force gas into the empty cylinder. Then one can open the empty cylinder and a wee bit of gas will escape.

 

[Tracy]

Just put a wrench on the valve and attempt to unscrew it. If you can, it is empty. You can't unscrew a valve with 1000 pounds of force holding the threads in place.