Author Topic: 80 CU FT oxygen tank (Read 1077 times)

Rickk · « **on:** June 27, 2006, 02:43:04 AM »

I just had an 80 CU FT Oxygen tank fail recertification (a bubble someplace near the threaded area when pressurized to 10,000 PSI). So, I'm out $200+ bucks for a new tank.

On the plus side, I have a tank that can be messed with. Anyone know what bore size I will find inside an 80 C.F. tank ? Way too small I'm sure for bowling balls, guessing 3-4 inches... no idea for sure.

Are they smooth and straight inside, or would it have to be machined to true the walls up?

Also, can I cut it with a chop saw, or is a more exotic method required?

Double D · « **Reply #1 on:** June 27, 2006, 04:19:11 AM »

Remove the valve, fill with water and chop it with a chopsaw....let us know if it works and what size the interior is....this from the safety guy???

Cat Whisperer · « **Reply #2 on:** June 27, 2006, 06:59:15 AM »

When I cut my tank I used a 4-1/2 angle grinder with a 1/16" cut-off disk in it. You'll wear out a disk on one tank. Use a sharpie to mark a line to follow.

Smoothness is about the same inside and out. Mine was the large tank, had a wall thickness of just over 1/4".

Rickk · « **Reply #3 on:** June 27, 2006, 07:15:52 AM »

Thanks CW...If an angle grinder worked for you that gives me hope.

A chop saw has a bigger, narrower blade and goes straight automatically so it should work even better.

DD's suggestion about filling it with water should keep the metal cool during the cut.

CW... what size tank did you use? If it was the same as mine, what are you shooting out of it?

Also, are tanks MIG weldable (trunions) ?

Cat Whisperer · « **Reply #4 on:** June 27, 2006, 12:35:52 PM »

If you are going to use the chop saw be very careful clamp the tube securely, it will try to roll. I cut up one of the big tanks, I thought it was 29-1/2 inches in circumference, but I'd mismeasured, so it was ALMOST bowling ball caliber. (I may have one of 7 that fits, and it's tight.) SO, I'll just have to reduce the diameter of each bowling ball when I finish the large radius cutter.

Rickk · « **Reply #5 on:** June 27, 2006, 03:43:39 PM »

if i cut it exactly in half this doesn't matter, but...

which end is better for a mortar... the normal "bottom" or the threaded top ?

GGaskill · « **Reply #6 on:** June 28, 2006, 01:48:48 PM »

The guns I have made from retired pressure cylinders were made from the neck ends. The insides are almost hemispherical while the bottoms are flatter and don't fit the shot so well.

quackgr · « **Reply #7 on:** June 29, 2006, 03:07:46 AM »

The way we done it was to drill a hole where you want to cut then take a stiff wire an put it in and measure it then measure the dia. of tank the differance is your wall thickness, then double the wall thickness to find your inside dia.

Gerald