SPG exploding when tank turned on?

[Wildcard]

I saw a welding reg blow once. The big thing is to turn it on slowly over say a full second or two and not just crank it open. As soon as the first rush of air makes it to the reg it should be safe.

 

[JungleJoe]

I was around when a stage bottle valve blew.... went strait up, through a wall and ceiling, through a brick exterior wall. was found embedded in a roof of a car about 4 blocks away.

He also lost his 2 front windows from the overpressure that resulted, but oddly no other glass display cases etc were affected. Needless to say, from sitting at a table in a chair and then BOOOM and the pressure increase in the air from a whole bottle venting it's contents at once was impressive.

Dunno why the burst disk did not pop, I think it was the threads that let go for whatever reason. It was thought that it had been crossthreaded at some point, I dunno... but I'll never forget that experience

 

[Ber Rabbit]

dang... i sux.... sorry dandyDon.... no i didn't - can the moderator move it? my initial thinking was this was cause for an accident, and was looking for actual first hand accounts and such....that's why i stuck it in here....

thanks for keeping us on an evenKeel dandyDon.... you da man!

The thread has been sent to "General Equipment Discussions" since that's really what it is
Ber :lilbunny:

 

[TavernierBob]

Yes. I've seen SPG's blow up 3 times since I've been diving. In all three cases the gauge was recovered, or what was left of them. Even though there is an overpressure hole and plug in the back the entire gauge pretty much exploded off of the hose, the glass shattered and the cases blew apart. When we found the remanants they were pretty much scattered over quite an area and one actually traveled about 30-40' through the air. No one had noticed any cracks in the cases prior to exploding but that doesn't mean they didn't have them. Once the remnants of the gauges were recovered it was impossible to tell as all 3 cases were significantly damaged. I've also seen 2nd stages blow and disintergrate in a cloud of plastic. Quite an impressive little explosion and luckily none of the gauges or second stages hurt anyone. Just lucky they were pointed in the right direction. Not by design but shear luck. For those that feel "it cannot happen" you've been listening to the manufacturers' propoganda way too long. Having one's gear serviced regularly and using common sense while initially charging your system are good things to practice. Bad things can and do happen. Not frequently but they can and have happened.
Safe Diving!

 

[SwimJim]

With modern well kept equipment, it's rather unlikely. However, I collect vintage stuff. Just last week I hooked up a newly aquired '70's vintage single hoser up to a tank that had about 1700 in it. The reg set appeared to be in good shape, and the subsequent tear down bore that out. About two seconds after I cracked the valve, "BOOM". Sounded like a .357 going off in the shop. The metal casing from the spg was still on the end of the hose and the little tube was in it yet. The rest blew out. I've always made it a practice to turn away the guage face when turning the pressure on. I believe I'll continue to do so.

Jim

 

[String]

Not seen the glass shatter but witnessed one in the summer where the SPG launched itself off the end of the HP hose. The glass/metal SPG missing a workers head by an inch or two and the rubber boot that also went flying hit her in the head knocking the person to the floor but luckily no more damage than a lump and bruise.

Myself being a coward and about 2 meters away just swore and threw myself down onto the beach on hearing the bang.

Looking at the SPG after the event the threads were covered in sand and worn away so only about 2 of the threads looked capable of screwing in properly.

A classic example of poorly maintained equipment being dangerous.

 

[SteveFass]

It was my understanding that if you get water in the first stage - oh, say by rinsing your reg without putting on the cap, something that I have never done, of course (ha) - then on your next dive the air will shoot the water into your spg blowing it off.

 

[String]

I seriously doubt thats true.

I can see how enough water in the first stage COULD corrode the SPG but thats more likely to cause it to stick or read inaccurately than explode im sure.

My regs after this summer were in a hell of a state, water had been inside lots of times, fair bit of corrosion and no doubt at all some would have gone from there into my SPG. Nothing exploded in 400 dives yet alone "the next dive".

 

[CAPNVINNY]

I personally watched the glass shatter on SPG when a DM in the Caribbean pressurized it.He failed to turn it away and it blew up in his face.We thought he was blinded and to this day I never pressurize a gauge without turning it away from me. He was fine,didn't even get glass in his eyes but it was exciting for a few minutes there.Oh and he did remark he thought it was strange the guage was filled with water,but he pressurized it anyway.Lesson learned!

 

[Soggy]

We've all been told since day 1 you should ALWAYS turn your SPG away from you when you turn on (pressurize) your tank

why?

i guess it might go back to the day when Jacques first turned on his tank back in the day, but has ANYBODY -EVER- heard of this actually happening?

Frankly, I turn the thing perpendicular to me since the back of most brass & glass gauges (like the ones I sell) have an over pressure plug to prevent the face from blowing. The plug could go flying, though and poke an eye out, I suppose so I turn it so I'm looking at the side.

On the other hand, when turning on and off deco or stage bottles, I am starting straight at the face.