Posted by Ken Kurtis on February 04, 2001 at 16:07:29:
In Reply to: Re: The Numbers/Shop Perspective posted by AADIVER on February 02, 2001 at 21:28:06:
(AA diver asked) What procedure do you use to fill a 3500 psi Sherwood Genesis so that it has 3500 when I dive it and not cooled down to 3200 or lower?
If you've got the time, we've got the time.
We'll fill it in water as slowly as reasonable (perhaps 200psi/minute) up to 3500, let it cool in the tank for another 10-15 minutes, see where it's cooled down to, then top it off to 3500. Assuming no one's in a hurry, this whole procedure would take around 35 minutes.
Part of the problem, from a shop perspective, is that a lot of times people are in a hurry for a fill. Then they think that they got a fast fill but it was a short fill. The physics dictate that the fatser we fill, even in water, more heat gets generated, which results in a drop in pressure when you finally use the tank. So if you want a full-full fill, please be willing to wait for it.
Ken Kurtis
NAUI Instr. #5936
Co-owner, Reef Seekers Dive Co.
Beverly Hills, Ca.