ASME Air Tank

[artbuc]

I just noticed that my vintage 2hp/12 gal Sears compressor came in two versions - one with an ASME tank and one with a regular tank. Both have 100 psig cut-off pressure but they have different safety valves. I have the regular tank. I discovered this because I cranked mine up to 125 psi and was surprised that the safety valve held. It is working fine so I know it is not stuck. The parts list does not specify the safety valve set point. Does anyone know how much pressure these tanks can safely handle? The obvious answer is 100psig but I suspect the ASME tank is designed for considerably more than that. Also, I suspect the regular tank is exactly the same except Sears did not pay for the ASME stamp. Thanks.

 

[jallyn]

Considering a plastic soda bottle can easily hold 100 psi without bursting the steel tank can hold considerably more. Mechanical engineers probably had a minimum safety factor of 2 (so 200 psi). For your own safety do not change the safety valve and stay under 125 psi.

Condition matters. If water is left in the tank for any period of time then rust weakens a spot on the inside, of course. That is why cheaper tanks these days are given an expiration date approximately 15 years after manufactured.

 

[artbuc]

Considering a plastic soda bottle can easily hold 100 psi without bursting the steel tank can hold considerably more. Mechanical engineers probably had a minimum safety factor of 2 (so 200 psi). For your own safety do not change the safety valve and stay under 125 psi.

Condition matters. If water is left in the tank for any period of time then rust weakens a spot on the inside, of course. That is why cheaper tanks these days are given an expiration date approximately 15 years after manufactured.

Thanks. I would not consider changing the safety valve. Compressor has had very light duty over the years and always drained after every use.

 

[Fur2nd]

Considering a plastic soda bottle can easily hold 100 psi without bursting the steel tank can hold considerably more. Mechanical engineers probably had a minimum safety factor of 2 (so 200 psi). For your own safety do not change the safety valve and stay under 125 psi.

Condition matters. If water is left in the tank for any period of time then rust weakens a spot on the inside, of course. That is why cheaper tanks these days are given an expiration date approximately 15 years after manufactured.

Asme requires a pressure test of 1.3 to 1.47 times the operating pressure to be held for a Minimum of 30 minutes as well as a level of ndt Nde