adam smith wrote:

I have a couple questions about air receiver safety. I have a 20
gallon ASME carry tank (Grainger 4TK10). It has two 1/2" air outlets,
but I want to use it to honk an old fire horn which is not working
when I plumb from just one of the 1/2" outlets. I need more flow to
maintain proper blowing pressure at the horn. So my questions are
these:

1. Is there a known maximum safe discharge rate for a 20 gallon ASME
tank? The tank has a plate rating of MAWP 175 PSI @ 475 F. I need to
meter out half-second blasts at a rate of approximately 80 CFM. Is
this safe to do from a 20 gallon tank? What about from a pair of 20
gallon tanks?

A short 1/2" line with full-port fittings and valves will dump 80 CFM at an
insigificant pressure drop, just a few psi at 175 psi.

Backing up here for a moment, the 20 gal tank holds 33 standard cubic feet
of air at 175 psi. That's less than a single half-second blast. If it's
taking more than a half second to dump the tank thru a 1/2" port, there must
be a restriction somewhere.

Bob