Hydrotesting air tank

[1190R]

I got a used air tank that I want to pressure test before putting into service using Keith Rucker's technique

I'm feeling pretty dumb at the moment because I've done this before but can't remember out how to connect my pressure washer to the tank
Everything on the tank is NPT and everything on the pressure washer is M22 or pressure washer specific quick connect
Can anyone out there remind me of how this connection can be made?

 

[tarmy]

Not sure that looks like a good idea…cause it could fail and that energy has gotta go somewhere.

Hydro testing I am familiar with involves over pressure testing in a static medium and measuring the displacement on the medium and using that displaced volume to determine integrity on the vessel based upon design criteria of that vessel. This testing is done in a containment structure design to minimize risk in a failure scenario.

This just looks dangerous to me. No containment and using non engineered methods. Good luck OP.

 

[Sumboodie]

Not sure that looks like a good idea…cause it could fail and that energy has gotta go somewhere.

Hydro testing I am familiar with involves over pressure testing in a static medium and measuring the displacement on the medium and using that displaced volume to determine integrity on the vessel based upon design criteria of that vessel. This testing is done in a containment structure design to minimize risk in a failure scenario.

This just looks dangerous to me. No containment and using non engineered methods. Good luck OP.

Much safer than air. I'm told it's how fire bottles are often tested.

 

[1190R]

Figured it out
My new pressure washer (Karcher) is all metric
An NPT male pressure washer specific quick connect from HD solved the problem

Powercare 1/4 in. Male to 1/4 in. Female Quick-Connect NPT Brass Coupler AP31038B - The Home Depot

The Power Care 1/4 in. Male to 1/4 in. Female Quick-Connect NPT Coupler enables you to transform your pressure washer into a Quick-Connect-capable machine that accepts a wide variety of attachments. This

www.homedepot.com

 

[The Cobbler]

Not sure that looks like a good idea…cause it could fail and that energy has gotta go somewhere.

thats why liquid is used, it has very little potential energy .
air, on the other hand under pressure has tons of potential energy.
think of a balloon filled with water and one filled with air. when you pop each one, which flies around the most shrapnel

 

[Steve_P]

Yeah, we've debated this before. There's the "right way" of sending it out to be done professionally, which almost no DIYer is going to do because of the cost and logistics, and the fill with water DIY methods, which seems better than just using it and hoping for the best.

 

[tarmy]

I think you guys missed my point. There is a way to measure the tank under duress/test pressure to determine if it is sound. Yeah, you can over pressure the tank with water and hope that test didn’t weaken the tank…but you really haven’t determined if it is a sound pressure vessel. The water test only shows that it held water to whatever pressure you applied…not that the tank stretched and recovered enough to be used under air pressure again. To each their own. That is why there is a limit to how many times a vessel can be over pressurized before it must be retired.

 

[PCustoms]

That is why there is a limit to how many times a vessel can be over pressurized before it must be retired.

Source?

 

[Sumboodie]

I think you guys missed my point. There is a way to measure the tank under duress/test pressure to determine if it is sound. Yeah, you can over pressure the tank with water and hope that test didn’t weaken the tank…but you really haven’t determined if it is a sound pressure vessel. The water test only shows that it held water to whatever pressure you applied…not that the tank stretched and recovered enough to be used under air pressure again. To each their own. That is why there is a limit to how many times a vessel can be over pressurized before it must be retired.

And what's that limit?

 

[LopezBart]

Steam boilers cannot be removed from service and placed in a giant tank. Here is a standard commercial techniques for the process:

The Hydro Test Procedure for Boilers – How Does It Work? | NiGen

A boiler hydro test is a stress procedure used to determine the integrity of all aspects of a given boiler unit.

nigen.com

This is what we do with our small steamboat boilers. It is also completely adequate for tested compressed air tanks at typical commercial pressures ( 175 psi) as well. There may well be other methods for extremely high pressure cylinders and the like - I'm not aware of them.

 

[tarmy]

For the scuba tanks I am most familiar with vary with material and manufacturer. The tanks max number (usually for steel is 9 cycles) also varies by the country of origin and testing. My point is to be informed about the particular vessel you are using and test appropriately to determine safety based upon what the spec is for the particular use. As the post above points out …there are applications and standard procedures based upon the vessel. Sorta my point…just use the appropriate procedure that is proven for the situation, Yeah, there are shortcuts and other ways for users to test their particular vessel….hence my comment about to each their own. **** that can, and sometimes do, have catastrophic failures I tend to be overly cautious about testing.

 

[welder4956]

For the scuba tanks I am most familiar with vary with material and manufacturer. The tanks max number (usually for steel is 9 cycles) also varies by the country of origin and testing. My point is to be informed about the particular vessel you are using and test appropriately to determine safety based upon what the spec is for the particular use. As the post above points out …there are applications and standard procedures based upon the vessel. Sorta my point…just use the appropriate procedure that is proven for the situation, Yeah, there are shortcuts and other ways for users to test their particular vessel….hence my comment about to each their own. **** that can, and sometimes do, have catastrophic failures I tend to be overly cautious about testing.

Scuba tank test pressures can be up to 5000 psi. Air compressor tanks test pressures are generally less than 300 psi. Not a concern for number of test cycles (i.e. fatigue).

 

[PCustoms]

Scuba tank test pressures can be up to 5000 psi. Air compressor tanks test pressures are generally less than 300 psi. Not a concern for number of test cycles (i.e. fatigue).

I think scuba tanks also have a 50yr max life, and require testing every X years, so at some point you "limit" out.

Most pressure vessels don't have a mandated use by date.