I know that. Now I wonder the next time I turn on the valve at work if the guy that set the tank followed all of the above precautions.
What if some clueless idiot put grease or oil on threads not knowing better and I'm the first to crack the valve?
It is pretty fair. Just bought 5# of black powder as part of a group buy. Got it for 11.00 a pound. It still is in the trunk of my car. I bet my little Saturn might have a chance to get close to its namesake if a fire broke out.
My couch isn't that sturdy and I've gained a few pounds. Have you kicked your dog today or did he bite you?
Five pounds of BP will lift an 120 lb. fireworks shell approximately 1000' high (out of a fairly close-fitting mortar).
SFX guys use two to five pounds with a "pole cannon" to roll cars at speed.
Five pounds would definitely blow all the windows and the trunk lid. It would probably also "alter" the basic body shape by inflating it. But I doubt it would disintegrate the vehicle. The ensuing fire would, though.
Actually, they left out the gross stuff. I'm pretty sure there was some VERY awful stuff a couple feet away from what they DID show. The guy who was wrenching on that cylinder when it went must have been one GODAWFUL mess! He may well have been partially incinerated.
ABSOLOOOTELY! Don't try to muck with THIS kind of problem at home. You mean to tell me you actually HAD A DOUBT? If it is their cylinder, I might drag it (far) outside, and call them to come pick it up. I might stand guard to make sure no kids come up and muck with it.
wrote: (clip)What if some clueless idiot put grease or oil on threads not knowing better and I'm the first to crack the valve? (clip) ^^^^^^^^^^^^^^^^^^ This may not be an exact answer to your concern, but it is close. When I was learning to weld, my mentor was the supervisor of a welding shop. He recommended the following procedure for starting a new oxygen cylinder: 1.) Attach the regulator, and just snug the fitting. Leave the wrench on. 2.) Barely crack the cylinder valve, until you hear gas leaking from the snug connection. 3.) Carefully, and slowly, finish tightening the regulator connection with the wrench. The pressure on the regulator gauge will come up to cylinder pressure. 4.) If nothing bad happens, finish tightening the regulator connection, and open the tank valve ALL THE WAY. 5.) If something starts to go wrong, quickly close the tank valve and loosen the regulator connection.
Each time you start a new cylinder, there is a possibility that a spider, or a fly, or some cobwebs got into the space. (Or one of your idiot buddies oiled or greased the fitting.)
They put the O2 in through the same valve you use to take it out. And, the people who do the refilling are HIGHLY trained. No idiots allowed within a thousand yards of where they do this. They all go through extensive safety training, and if they aren't awed by the potential for danger if you screw up, they don't work there.
Oh, I'm just pointing out that this guy was using a big wrench on the valve. I guess he used it on the valve body, originally I thought he was cranking so hard on the valve STEM that he unscrewed the whole valve from the cylinder. Any time this sort of abuse is applied to a pressurized cylinder, I would treat the thing as a bomb. Now, before the guy wrenched on it, it may or may not have been a hazard, depending on the presumed trouble in the valve. Maybe somebody just broke off the knob, and the valve wasn't really damaged, just couldn't be operated.
We had a pretty spectacular fire in St. Louis last year, when a Propylene cylinder started venting at Praxair's bottled gas facility. It was sitting either in a truck, or in the yard, in the hot summer sun. They had a known problem with the safety valves on these cylinders relieving at well below the designed pressure (of the valve, not the tank). This time, something ignited the venting gas, and they didn't have a deluge system. About 15 minutes later, the whole yard started blowing up, and acetylene and other cylinders were shooting around town like an artillery barrage. I think there was only one fatality, and that was an asthma attack that couldn't be treated in the middle of a war zone.
I'm sure the people who do this for a living have a procedure for safing a pressurized cylinder with a jammed valve. I suppose if you do something to it in a swimming pool, the danger is reduced. Anybody know? The O2 tank is definitely a special case, as once it gets started, the tank itself becomes the fuel.
I had a tech working for me who spent $3000 ordering ammo components over lunch about a week before Y2K. He had 140# of smokeless sitting in his living room. He moved on to another job not long after.
I got my all time favorite quote from him: "I believe the best value for your entertainment dollar is gasoline." That was said with a completely straight face. This was when I lived in Texas, not Michigan.
Neither, My dog is doing what she does best, cuddling up with me, keeping my feet warm under a blanket. (she's not very big!)
I tend towards sarcasm when some guys start to get on a "safety" streak as a result of some dumkopf doing something dumb.
Too many years of dealing with new rules brought on by the evolution of the better idiots, those that keep finding ways to get past the idiotproof stuff, resulting in stuff that is supposedly even more idiotproof. The death of common sense and all that.
I figure that welding tanks are as safe as, or safer than a lot of things that we deal with every day. That this one guy got hurt doing something that he probably knew better than to do, is not reason to look at welding tanks any differently. Also, IMO you should already know enough about the potential in a set of welding bottles that the information presented, and it's context, should give you no worries. My personal favorite is seeing the guys with these bottles on the little carts, standing out back of the hospital sucking on a cigarette, and wondering that we have never heard of one of them catching fire. I think that tidbit should put the risks in some perspective, too.
Even with training, the system fails at times. A painter at one of the Canadair plants was killed when he hooked to a breathing air bottle to do some painting under an instrument panel of a plane on the production line. Turned out the bottle was filled with nitrogen (IIRC, inert and odorless in any case). He suffocated, as he had to lay on his back on the floor to shoot the underside of his work, and was not noticed for quite a while. Had he been working upright, he may have been noticed collapsing, but..
It was traced back to one of those higly trained individuals relying on the fittings as a guide to what went in the bottle. The fitting fit, the bottle got filled.
I have seen a few guys that knew better, do the odd stupid shit thing around aircraft O2 systems, but have never been around when one went for shit and burned. I'm pretty happy about the latter point, too.
I agree with the heat/dust explanation but I am surprised only one person so far has mentioned the chain clamp. The edges of the chain would certainly gouge/weaken the outside of the tank which when combined with the other elements led to the catastrophic failure of the cylinder. the fire and pressure release alone is unlikely to have caused the top of the tank to separate the way it did. but if you first score and ring around the cylinder....bingo. i wouldn't be surprised to find out that the scoring of the outside of the cylinder alone could lead to such an explosive failure. If you watch the video of the myth busters knocking the top off a large cylinder you will see a missle in action but no tank rupture. As well with O2 coming out of the end of the tank at 2000psi I don't believe the fire/explosion would enter the tank.
Like I said. It ain't rocket science. You don't screw around with causing stress risers on a highly stressed part. The escaping high pressure oxygen burned what it came in contact with - and was a RESULT, not the cause.