On 6/23/2010 3:57 PM, Don Foreman wrote:
On Wed, 23 Jun 2010 13:50:07 -0700,
wrote:

On 6/23/2010 12:21 PM, Pete C. wrote:

Don Foreman wrote:

(...)

What happens with a 5 gallon jerrycan with 1.5 PSIG inside? Well, the
vapor pressure of "summer" gasoline varies about 3.5 PSI from 50F to
90F, so a jerrycan certainly can handle 3.5 PSIG without problem.

A 20 l jerrycan has about 10% the internal surface area of a 55 ggl drum.

The flat top& bottom of a 55 gal drum have areas of about 380 in^2.
The 13" x 18.5" flat sides of a jerrycan are 240 in^2. The
cylindrical part of a 55 gal drum could probably stand upwards of 100
PSIG, it's the flat surfaces and seams that dictate.

Hokay but the drum still has 2.8 x the seam length of the jerrycan.

I stumbled across a claim that the flat top and bottom
of the drum go noticeably convex at only 5 PSIG.

Gives me the willies, it does.

I'd stay with a lever pump and keep the
'air over oil' pressure down around 0 PSIG.

The pump would be a great metalworking project.





--Winston