Poor man's tank pressure checker

[DavidInNH]

Hi all!

I've got a retired SPG and access to an old first stage and would like to assemble them together to make a tank pressure tester. This is so that I don't have to hook up my dive computer (with integrated SPG), start it and wait for it to go through diagnostics and then run for 2 hours, decreasing battery life - just to check tank pressure.

The only problem is that I need some mechanism to vent the pressure so that I can disconnect the first stage from the tank. Since I won't have a second stage, I was wondering if there's some kind of venting apparatus that I could put on the first stage to accomplish this goal.

Thanks in advance.

 

[dannobee]

Hook a low pressure hose off of the 1st stage, then use a "air blower" on the end of the bcd quick disconnect.

You can buy a tank checker here for $50. The low pressure hose and air blower might cost almost as much and the SPG likely won't be as accurate.

 

[DavidInNH]

Thanks for the suggestion. The link is to a DIN checker so I'd have to find a yoke one but I might replace the air blower in your suggestion with a tire inflater (which I've wanted to get as well), so it might just be the cost of the LP hose. The SPG is the old one from my now-retired console so, since it has been accurate enough for all these years, should continue to serve me well.

Thanks again.

 

[Scared Silly]

BTW having an old reg with a lp hose is great around the house. I use it to fill tires on vehicles - especially cause you want to check the pressure when they are cold.

 

[WVMike]

You need to add an over pressure relief valve to your unit as well. Once all this is said and done a tank pressure checker might not look so expensive.

Regulator Accessories - Dive Gear Express

 

[Scared Silly]

Given that the reg is going to be used for a non critical stuff I would not worry about an OP valve. If the first stage has a problem and the IP gets jacked up then the LP hose will burst.

 

[Aceboyd]

And that is acceptable? lol

 

[herman]

Just stick a short 3/8x24 (SAE fine) bolt with an oring behind it into one of the lP ports and don't tighten it. You can screw it out a little to vent the reg. Who cares if it leaks a tiny bit, actually that would make it self depressurizing........a port plug without an oring snugged down might do too if it does not leak too much. From a flow prespective, if you can't stand a little leaking of the LP side of the reg, there is something wrong. Thinking about it for a little, an overpressure valve is not a bad idea, a run away IP could do some interesting and exciting things to the reg if it can't vent.