Respect Compressed Air

Back at school we had a 220 bar hydrogen cylinder about 5 feet tall fall and neatly shear off the valve - when we could hear and think again we saw the hole through the concrete block wall, the fence, the school head's new car... it came to rest in a field after passing through a brick wall on the far side of the car park :/

I'm still scared of gas cylinders.

Dave H. (the other one)
 
On a lighter note, once upon a time, I slid the sleeve back on a quick connect coupling so the plug/hose popped out. The hose end did a backflip and smacked my girlfriend on the top of her foot.
She was not at all happy. Acted like suffering the most pain since child birth.
Subsequently, I noticed she paid a little more attention to the proximity of air fittings.
 
I was on the verge of calling BS regarding the multiple references to unscrewing the 2" plugs/fittings on an air receiver.

When I've had to remove them, there was nothing casual about it. It took a 24" pipe wrench + cheater, had to tie the receiver to the wall and apply all the grunt I could muster.
 
I just remembered that I was once responsible for a potentially life threatening laps of intelligence with compressed air.

In about '78, my employer bought a used 4' kick sheer that had been converted to pneumatic by a previous owner. When it arrived it had a 4x4 lagged under each support leg. I figured they were there for transport purposes only and removed them (the importance of this will soon be clear). The sheer was in rough shape so I took bits apart and made adjustments/repairs as I thought appropriate. After reinstalling the air cylinder and treadle, I decided to use air to retract the cylinder. I put a nipple on a hose from the cylinder and plugged it in to shop air.

!!! BAMMM !!! The cylinder EXTENDED and the treadle hit the floor causing the machine to flip onto it's back. !!! BOOM !!!

The 4x4s were needed to clear the travel of the modified treadle. And, obviously, yours truly charged the wrong hose.

People came from distant parts to see WTF? No physical injury befell any persons (thank God) or the sheer (small dent in the concrete floor).

My embarrassment hit a new record high and I suffered additional discomfort from the massive, instantaneous injection of education. That was bad, but I feel much better now.
 
I would have definitely removed the 4x4's as well... it's unusual to see machine modifications made of wood :/
 
Finally the pressure was down to around 25 psi. That didn't seem like much at all to me, figured I could just finish unscrewing the plug and catch it as it came off. :dejected:
Ahhh, youth. I have something similar. I was unscrewing the valve, it quit hissing so I though the pressure had bled off. One quick turn an BAM, 300 psi of oxygen sent the valve ricocheting off the fuselage three or four times before it stopped. No one was hurt and I never found the valve. :D
 
Last edited:
Back at school we had a 220 bar hydrogen cylinder about 5 feet tall fall and neatly shear off the valve - when we could hear and think again we saw the hole through the concrete block wall, the fence, the school head's new car... it came to rest in a field after passing through a brick wall on the far side of the car park :/

I'm still scared of gas cylinders.

Dave H. (the other one)

This reminds me of several stories I've heard over the years. One in particular, happen at a company over on the east side of Houston on Navigation boulevard. Anyone who deals with the oilfield may know of whom I'm talking about. The incident took place in the 1970's. They were testing a tool with nitrogen in a piece of pipe when a 3-1/2" Pipe bull plug let go at around 5,000 psi. It went thru a cinder block wall across Navigation Boulevard and who knows where it went from there. It was never found nor did it take out any cars in it's path on that busy street!
 
I had built a wood powered boiler with a storage tank the was 5x5x5 feet. Across the centerline of the tank was a steel bar anchored on each end by a 1/2 inch grade 5 bolt to prevent bowing. I was planning on running the tank pressurized to 10 psi so I was testing it with my compressor. While slowly increasing the pressure one of the bolts sheared right off and I was only at 3 psi. Doesn't sound like much but 3 psi over a 5 x 5 ft area is over 10,000 pounds of force. I ended up venting the tank to the atmosphere.
 
I can attest to that one, just a little to much air on the bearing and all of a sudden there is an explosion of parts, and those little balls hurt, How does a ball that size go through such a small hole in the skin.
Another thing one can do with compressed air is to take a large hex nut and spin it on a screwdriver shaft with your air nozzle to the point of it screaming and then tilt the driver downwards so the nut creeps off the end and hits the ground and goes flying like a bat out of hell ---- of course do not attempt this at home!!!! Apprentices where I worked were known to do this caper and scare the S--- out of whoever was in range; none that I aimed at were unable to get out of the way.
 
Back
Top