The most dangerous accident in my career thus far occurred a few days ago and I think it would be better to share it than bury it (along with my head) in the sand despite my desire to. I’ll preface this with the fact that no one was hurt, and I was the only one who would have suffered direct injuries from this, which was by design and my only saving grace here.
I was installing a nitrogen line between my extraction setup and nitrogen generator and I prefer soldering hard line copper for most of my gases and heat exchange lines since I am qualified to install it, it’s cheap, long lasting, and osha approved for compressed gases. I had assembled the main spine of the line and pressure tested the main line with the generator to ensure all my joints held. I was extra careful to inspect and clean each joint since it’s a long run and in the ceiling, making leak hunting laborious. No surprise, held wonderfully.
I come back the next day to finish the work on the ends that would connect to my manifold. I inspect a joint between a valve and pipe on the other side of the main line that looks like it may have a small gap; I like to ensure these are sealed and I hit it with a touch of flux and solder (I know this is controversial, but I’m anal about my surface perp, so leaks are mostly due to a lack of solder). I had to warm it up quite a bit as valves have quite a bit more mass to heat up but my map torch gets it up quickly so I can start to add solder.
For a brief moment, I see the valve shift slightly, before it shot off violently towards the ground. A small amount of molten flux and solder sprayed my face and there was a loud pop that left my ears ringing.
I had left the generator on overnight and hadn’t depressurized the line; when fixing the joint on the non-pressurized side of the valve, heat travelled up the valve to a joint under pressure and melted the solder enough to cause the system to rapidly depressurize. Nothing was broken, I didn’t sustain any burns or lasting hearing damage. The valve was also point down and it fortunately shot away from me, not harming my feet.
This was a mistake I was better than making, I usually double check during normal operations all my valves and gauges and am classified by my co workers as a paranoid maniac, but I had forgotten to shut off the generator, close the valve and depressurize the line; this is a rookie mistake in my opinion, though gases are a bit more hazardous than water. I felt and feel stupid about this and have scrutinized myself harshly.
Despite this, I’m not really shaken up by this at all; I’m not afraid of death and perform dangerous work constantly (soldering, climbing, fabrication, chemistry). Danger and hazards are inherent to the things I want to do; I’d rather die than not do the things I find compelling or interesting.
However, mistakes will happen and in our line of work and they can be easily fatal. You are responsible for your safety, and you must ensure accidents aren’t fatal when they occur. I removed all flammable solvent from the room, I always stand back from pipes since I’ve had valves burst on me for no reason and steering clear of potential projectiles is a good reflex to have. This valve shot off so fast that there is no way for me to have avoided it; I blinked and missed it.
I figured I’d tell this story because I think everyone can learn from this in their own way. Proffessionals can make mistakes; mine was absent minded and I’m going to be more present when doing construction work like this and make sure anyone I work with does so as well.
If anyone is willing to share their accidents, spills, or anything of the sort, I’d implore you to share them. Reading about other’s mistakes has prevented me from making many more foolish mistakes like this one.
