Tank PSI - Over Filled, Drain or Dive?

[Peter69_56]

It appears to me that most regulators are designed to take 300 BAR/4400 PSI, its just the fitting from the reg to the tank that's the potentially weak link. An example of this is my CDX-5 reg which with a K valve fitting is rated at some 235 BAR (stamped on the K fitting), change the fitting to 300 BAR DIN and its now rated at 300 BAR (as per the stamping on the side of the reg and the DIN fitting). I suspect most (if not all) regulators are built to the higher rating as its no big deal for the manufacturer to do this anyway and makes manufacture easier with one pressure rating, then they put on the connector piece to suit the application thus the drop in working pressure. This also allows them to sell more primary regulators when people think they have to update their reg for a high pressure one from K valve style when changing to tech diving (and usually going to DIN fittings). All my regs are now converted to DIN so all rated at 300 BAR. If I need to use a K valve tank I simply add a converter (rated at 232 BAR) and use the tank. In this way I can use 300 BAR/4400 PSI DIN tanks, 232 BAR/3500 PSI or 200 BAR/3000 PSI K or DIN tanks.

Most of the tanks in OZ are tested to 300 BAR/4400 PSI anyway but I don't like having them at this pressure unless the WP is 300 BAR/4400 PSI

 

[MrChen]

Because the OP tried that, had an O-ring failure and is having second thoughts. A steel tank does not a diver make.

Pete

Correct. I'm not concerned the tank will fail, but I am worried about the yoke valve at that pressure now.

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[macado]

Because the OP tried that, had an O-ring failure and is having second thoughts. A steel tank does not a diver make.

Pete

Ah ok. I misunderstood. Thought he had replaced the o-ring and was good to go. In that case, technically pressure is a little high for yoke and you can get o-ring failure/extrusion like what happened. I'd prefer DIN at that pressure but I've run yoke at 3900-4000psi before without issue; I just don't do it on a normal basis.

Should hopefully be able to breath the tank down a bit until it's not a problem, not advocating everyone does it but it's a risk some people take.

 

[Paulmal]

Anything under 3000 is a short fill on every tank I know off.

 

[Peter69_56]

yes I agree < 200 BAR/3000 PSI does not make for a happy dive.

 

[rongoodman]

I thought that number stamped on the tank was supposed to be the turn pressure

 

[MrChen]

Ah ok. I misunderstood. Thought he had replaced the o-ring and was good to go. In that case, technically pressure is a little high for yoke and you can get o-ring failure/extrusion like what happened. I'd prefer DIN at that pressure but I've run yoke at 3900-4000psi before without issue; I just don't do it on a normal basis.

Should hopefully be able to breath the tank down a bit until it's not a problem, not advocating everyone does it but it's a risk some people take.

This is the type of feedback I'm looking for.

Makes me wonder why yoke is so popular in the US. I know the dive shops in my area carry tanks for both yoke and din, but most likely not in the same quantities.

After blowing that o-ring at 4000, I'll most likely let out a couple hundred pounds before jumping in the water.

 

[Paulmal]

I thought that number stamped on the tank was supposed to be the turn pressure

They are, it makes it easy to do thirds. Fill the tanks to 3600, turn the dive at 2400, and surface with more than 1200. Having the turn pressure stamped on the neck just help with the math & remembering when to turn.

 

[Peter69_56]

They are, it makes it easy to do thirds. Fill the tanks to 3600, turn the dive at 2400, and surface with more than 1200. Having the turn pressure stamped on the neck just help with the math & remembering when to turn.

WP=Working Pressure
TP=Test Pressure

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[crosshairs]

I would be happy with 3500 in my HP tanks....all I ever get is 3000..if I'm lucky.....