oxygen tank death

[abnfrog]

ok fair enough , but hi pressure air and o2 is used by use so much I think we lose prespective on what we SHOULD be doing , that why I stay up on it as much as possible ..AND to impart that to my students doing vip and 02 cleaning / blender

 

[Peter69_56]

There is no way you are going to hand loosen a 3/4" NGT CGA 540 valve that is properly installed. The torque required is huge - like 600+ ft/lbs
Pipe Thread Installation Torque Table Chart | Engineers Edge | www.engineersedge.com
54 in/lbs * 12 = 648 ft/lbs (edit should be divide so 54 /12 = 4.5 but this source is incorrect)
If its not properly torqued, its going to leak long before you move it.

So it most likely broke off, or based on the pictures the cylinder threading corroded to the point of failure.

Ever tried to unscrew a scuba tank valve with 10 BAR in it? The pressure lockes the thread, regardless of if it is loose when empty or not so I would think it would be near impossible to unscrew the valve past the point where it comes out. However some commercial tank valves have tapered thread, so I am wondering if it was faulty thread/damaged, and this with the taper of the thread has allowed the valve to blow out? Just a thought anyway.

 

[grf88]

Ever tried to unscrew a scuba tank valve with 10 BAR in it? The pressure lockes the thread, regardless of if it is loose when empty or not so I would think it would be near impossible to unscrew the valve past the point where it comes out. However some commercial tank valves have tapered thread, so I am wondering if it was faulty thread/damaged, and this with the taper of the thread has allowed the valve to blow out? Just a thought anyway.

The report stated that corrosion around the valve was a suspected cause. Quite possible that the corrosion allowed the cylinder to stay gas tight until disturbed by rough handling.

 

[TrimixToo]

I will try to post a picture of it. It’s base metal is 6061 hex bar stock, maybe 1”, maybe 1 1/4”. The end is a perfect hemisphere, with DIN male threads.

Here is one like it, with a different business end.View attachment 545390

Thanks for posting the pic, Frank. I finally got around to making one. I went with Aluminum because I didn't have a handy diameter in SS, and I put a projection on the end to bottom out before the larger diameter contacts the sealing surface inside the valve.

 

[Wookie]

I have not seen that type of collet on a lathe before, does it have a name?

 

[JohnnyC]

I have not seen that type of collet on a lathe before, does it have a name?

Looks like a 5C collet chuck.

 

[TrimixToo]

Looks like a 5C collet chuck.

Technically, a 5C collet closer. I had a 5C chuck on the previous lathe. The closer is *much* faster to use.

 

[AfterDark]

Underestimate the power of compressed gas at your own risk.

 

[SoFlaDiver954]

Underestimate the power of compressed gas at your own risk.

View attachment 560613 View attachment 560614

Top picture, left two tanks. Are those the concave bottom euro steels or are those aluminum? Flat bottom (and apparent sidewall thickness on the middle tank) is saying aluminum but the failure looks like more what I expect from steel.

 

[AfterDark]

Top picture, left two tanks. Are those the concave bottom euro steels or are those aluminum? Flat bottom (and apparent sidewall thickness on the middle tank) is saying aluminum but the failure looks like more what I expect from steel.

I don't really know as no details came with the pictures. The 2 you mentioned look like flat bottom AL tanks, possibly the old Al alloy forget the number, that is no longer touched by a lot of LDS. As indicated by the rust the others are steel.

Taking another look, the lone tank on the right, it looks like an air bank tank, a 400cuft tank note how long it is, must have been an exciting day when that ruptured!