Depressurizing plugged first stage

[Gyula Fora]

I know this is a stupid question but lets just treat it as a thought experiment.

Let's say you plug all the ports on a first stage and connect it to a tank, then you pressurize it. How would you remove the first stage afterwards (depressurize it)?

 

[rhwestfall]

turn a port plug until it pisses. Then replace the o-ring....

 

[rhwestfall]

back in the archives somewhere is a hysterical write-up of this including a face shield, ear protection, heavy gloves, a catcher's chest protector, and, IIRC, an athletic cup all being utilized with a disappointing (less than cataclysmic) outcome....

 

[Storker]

Frankly, the idea of taking the trouble of first removing one HP hose and four LP hoses, then finding five plugs to plug up the holes, screwing them in and finally attaching the first stage to a tank has never occurred to me. And I'm pretty certain that if you hadn't come up with it, I'd never ever consider the possibility. What for?

 

[Justin Bove]

I asked that very question to my OW dive instructor. He said he had a friend do that by accident. Friend got a new 1st stage regulator and for some magical reason plugged the LP and hooked up his SPG to a HP port to test his tank pressure. Took a couple of weeks before the pressure went down enough to safely remove DIN 1st stage from valve.

 

[Gyula Fora]

turn a port plug until it pisses. Then replace the o-ring....

Hm, I thought it would be too hard to turn, but then again I never tried...

 

[rhwestfall]

You ever have a DIN tank valve plug get pressurized (apparently not)? A wrench solves that...

 

[caruso]

It's an easy thing to do by mistake. I was once troubleshooting an issue and disconnected the primary 2nd stage, the LP inflator hose, and the SPG from the first stage, and replaced them with plugs. I was about to connect an HP gauge to the regulator and thought about it. "If I do this and open the valve, there will be no way to depressurize the system and that would be bad".

 

[divinh]

turn a port plug until it pisses. Then replace the o-ring....

Which would be a better choice? HP or LP? Burst hose says LP will have the most rapid release, but HP might be too dangerous?

 

[JackD342]

Having on occasion experienced an HP 1st stage port o-ring extrude and leak or the gauge hose torque itself out a thread or two, I think that loosening the HP port could be managed okay.