Scubapro SPG Failure

[ciocanul]

You could heat up all parts. The plastic cover and the o-ring will slide into the case. Fixate all parts, let it cool down and it will be (should be) tight when cooled down.

Best wishes Jens

That's how I'd do it if it still worked, but right now it's just scrap metal

 

[ciocanul]

A little update. I injected a few drops of vinegar in it, pressurized it and voila! It got unclogged and works as new. The vinegar will most likely never come out of the coiled tube, but it will chemically balance with the brass, as all the acetic acid will react with the copper, consuming a minuscule amount of the metal tube.

 

[Pearlman]

So what happens if the SPG or it’s over-pressure O-ring blows at 30m below?

 

[Thunder Struck]

A little update. I injected a few drops of vinegar in it, pressurized it and voila! It got unclogged and works as new. The vinegar will most likely never come out of the coiled tube, but it will chemically balance with the brass, as all the acetic acid will react with the copper, consuming a minuscule amount of the metal tube.

The stiffness of that tube is what the air pressure reacts against to ultimately display your tank pressure. Anything affecting that thickness will likely change the reading. If it was to completely spread evenly over the entirety of the tube perhaps it wouldn’t be enough of a difference to make a difference. But I’d be inclined to wager it’ll concentrate on one area.

Seems to me you’re tripping over a dollar to pickup a dime. If it was just part of a reg being used in pool sessions, no big deal when it fails. But being on a multi thousand dollar trip and to have it fail would be a bit more impactful.

 

[Belzelbub]

So what happens if the SPG or it’s over-pressure O-ring blows at 30m below?

You head to the surface. Good news though is that you have some time. The air pathway in an HP hose is tiny. The LP hoses on the other hand are much larger. A failure of the HP hose (or SPG) will empty a full AL80 in about 22 minutes. A LP hose failure will empty that tank in just over a minute.

 

[ciocanul]

The stiffness of that tube is what the air pressure reacts against to ultimately display your tank pressure. Anything affecting that thickness will likely change the reading. If it was to completely spread evenly over the entirety of the tube perhaps it wouldn’t be enough of a difference to make a difference. But I’d be inclined to wager it’ll concentrate on one area.

Seems to me you’re tripping over a dollar to pickup a dime. If it was just part of a reg being used in pool sessions, no big deal when it fails. But being on a multi thousand dollar trip and to have it fail would be a bit more impactful.

Firstly, to take the safety issue out of the way, I will not be using this SPG on dive trips, it is just a fun little experiment. On the technicla side, you're theoretically right. But little chemistry that I remember, the few molecules of acid in a drop of 6% dilution of acetic acid will react with way fewer molecules of copper. So yes, there will be a variation of thickness, but i bet it will be in the .01% range. Look, I have 3 different spg-s. On a full tank one shows 200bar, one 210 and one slighlly under 200. When they go to zero, the needles hover around the zero mark or rest on the stop pin, so what are we talking about ) ?

 

[Ukmc]

Firstly, to take the safety issue out of the way, I will not be using this SPG on dive trips, it is just a fun little experiment. On the technicla side, you're theoretically right. But little chemistry that I remember, the few molecules of acid in a drop of 6% dilution of acetic acid will react with way fewer molecules of copper. So yes, there will be a variation of thickness, but i bet it will be in the .01% range. Look, I have 3 different spg-s. On a full tank one shows 200bar, one 210 and one slighlly under 200. When they go to zero, the needles hover around the zero mark or rest on the stop pin, so what are we talking about ) ?

Segal’s law