Posted by JR Gordon on November 30, 1999 at 20:12:37:
In Reply to: Cyliders posted by Suzanne Messina on November 30, 1999 at 13:11:54:
Suzanne,
Have you considered a LP tank.
A LP-95 when filled to 3000 lbs. holds just under 120 cu.ft. This tanks weighs the same empty (38lbs) as the HP 120, and it's 4 inches shorter. They have similar bouyancy characteristics when full; but the LP95 is negative 1.2 lbs. empty vs. + 1 lb. for the HP120.
Another consideration is that in real world physics, due to molecular interactions at very high pressures, we get less volume than predicted via the ideal gas law. Even if you could pump 3500 into that tank, it would settle into 3100-3200 lbs. giving you something in the range of 108 cu.ft. You could get that out of the LP95 at only 2700psi. And LP tanks won't rust out as quickly. There's even a LP95 at auction on E-bay that unfortunately goes off in 10 minutes!
http://cgi.ebay.com/aw-cgi/eBayISAPI.dll?ViewItem&item=204572529
Just my $.02,
JR Gordon