On Mon, 17 Feb 2014 08:24:24 -0500, wrote:

On Mon, 17 Feb 2014 07:43:52 -0500, wrote:

On Sun, 16 Feb 2014 23:50:19 -0800, "Bruce L. Bergman (munged human
readable)" wrote:

And I'd condemn both of those tanks if you can't get them Hydrotested
for safety. If they blow up in your face it's going to ruin your
month, if not the rest of the century.


Refillable propane tanks are spec'd at a working pressure of 250PSI
and a burst pressure of 500psi. One tank out of every hundred or so
needs to be tested to either 3 times working pressure or twice burst
pressure for certification purposes.

actually ""Performance and integrity of the propane cylinders were
established by burst testing each of the 236 test cylinders. The
minimum design burst pressure criterion used here is 960 psi, or four
times the service pressure of 240 psi, consistent with typical DOT
requirements" from
http://www.propanecouncil.org/files/...port_Final.pdf

Actually it is -
_FS-10202 Pressure ReliefValveandPropaneCylinderPerformanceTesting.pd f

Propane is supposed to be water and oxygen free, and the inside of
50-year old bottles should be pristine steel - and they come un-lined.
Air receivers are the exact opposite - that's why they get painted or
other corrosion coating on the inside before sale, and why they have a
drain valve and 2" inspection ports with plugs.

Propane bottles /used as/ air receivers don't have any anti-corrosion
coating on the inside, or inspection ports, or drain ports and valves
to regularly remove the condensate. That is a recipe for disaster.

If you welded in a 1/4" NPT port for a drain valve and a 2" inspection
port in a new propane tank and got the inside painted, then I
wouldn't have any arguments with repurposing it into an air receiver.
But your homeowners insurance company might.

-- Bruce --