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Re: Pressure Testing
David,
The high pressure pumps you asked about are most likely "differential piston
pumps" similar to the ones on the following web site.
http://hiipumps.com
These pumps use a large diameter piston (maybe 4 to 8 inches) driven by shop
air (about 90 psi) to push a small piston (maybe 1 to .1 inches, hence the
differential) which pumps the liquid. PA=PA (pressure times area of the drive
piston equals the pressure times area of the driven piston). The liquid side
has check valves to keep the flow from coming back when the pump strokes in the
opposite direction to reset. These pumps can compress air at two times the
drive pressure (at the low end) on up to pressurizing liquid up to 100,000psi.
The cost of the cheapest (not the lowest pressure!) pump is probably about
$500. I am familiar with some mid-range (5,000 to 10,000psi liquid) units
which sell for about $1250 to $1500.
As far as using an air compressor to directly pressurize the tank, bad idea,
too much explosive potential with air. You could even use a hand pump but you
would get a good workout if there is much air in the tank or it is big (air
compresses 1000 times as much as water and big tanks expand a fair volume. I
have designed test chambers for hydraulic hose and tubing with pressure
capability up to 20,000psi using these pumps. I have also used test apparatus
which tests gauges up to 5,000psi. The hose testers use air driven pumps and
the gauge testers have a hand cranked screw driven pistons.
Hope this helps.
Dick
David Buchner wrote:
> >On a real sub underwater, the pressure is applied all around the sub, not
> >in one point. Though, IIRC, real subs are tested in large sealed tanks,
> >if there's no air inside the tank it can be surprisingly easy to get up to
> >a high pressure(same idea as doing a hydro on a boiler). TTYL!
> >Paul Anderson
>
> A couple of folks have mentioned such test-tanks. I wonder how they get
> pressurized. Would a big air compressor do? A big column of water in a pipe
> sticking out the top?
>
> ---------
> David
> buchner@wcta.net
> http://customer.wcta.net/buchner
> Osage MN USA