Normk wrote:
Daryl, perhaps your can clarify some points?
IME, PCP rifle reservoirs fill to 3,000 or 3,500 PSI.
SCUBA tanks generally fill to ~2,200 PSI, however there are high pressure SCUBA tanks which fill to 4,000 PSI.
A 2,200 PSI SCUBA tank cannot fill PCP, and 4,000 will drop to below 3,500 in only a few fills.
Do you know anyone using 4,000 PSI SCUBA? I'm curious as I haven't encountered any, although perhaps they are very common in commercial and such applications.
SFAIK, nitrogen tanks are only available for 2,000 PSI from any supplier I have contacted, in BC. Do you know of a source? I might try that for fun if can find a source which isn't too pricey.
Who knows if nitrogen can improve my groups? As it is, they guys are encouraging me to try out for the CNIB team.
My 60 cu in Scuba tank is a 3,000psi tank & since it is steel, it is supposedly fill-able to 3,300psi. That is what the scuba-tank filling guy out in the North of town used to fill it to.
Someone on this site noted the aluminum tanks were maxed at 3,000psi.
I had 2 carbon SCBA(I think) tanks I bought used, from Rick's place in Ontario. They are 4,500psi tanks & that is what I filled/fill them to.
These are 77 cu. in. tanks, seems to me - maybe slightly larger than that.
There are 2 outfits in town here who have 4,500psi Nitrogen tanks. I named one, Praxair. The fellows in town who are not shooting indoor air rifle silhouette are using the other outfit.
That one might be Air Liquide on the street behind Central Street.
The 4,500psi nitrogen tanks we rent/rented, are 200 pounds and hold 34 cubic feet of nitrogen. One lasted me a year of shooting, getting it down to just under 3,000psi after the 12 months of shooting.
I just recalled that when talking to one of the local chaps at the range a week or so ago, he noted the "other" supplier in town could also get 6,000psi nitrogen tanks for rental purposes. These of course, would require more expensive gauges than the 4,500psi gauges for the 4,500psi nitrogen tank.
You do not get gauges with the tanks, just the tanks. I bought my 4,500psi gauge and whip system from Air Tanks for Sale, Joe Brancato, in the States. Not cheap, but not too bad, either.
Found this on his site:
"NITROGEN HOSE ASSEMBLIES MADE IN USA! Nitrogen tanks are readily available at most welding supply shops and they are usually cheap to rent! Also, they are 6000 PSI, so you get an amazing amount of fills. If you wish to fill your Carbon Fiber tank from a large Nitrogen tank, this is it. STAINLESS STEEL tank fitting, STAINLESS STEEL Glycerin Filled Gauge that reads BAR & PSI, Highest Quality STAINLESS STEEL Bleeder with easy to turn knob and 40" x 0.070 inch ID micro-bore hose with STAINLESS STEEL strain relief at each end and STAINLESS STEEL "Foster" type quick fill = $189 + $14.50 shipped priority mail and insured."