This may be a stupid question, but I need to know. Do the nitrous bottles need to be hydro tested every three or five years like my compressed air tanks for paintball? I ask because certain tanks do not need re-hydro.
In the Operating Room inside hospitals Nitrous tanks get hydroed every five to ten years just like everything else (Nitrogen, Argon, Oxygen...). Stand alone tanks every five years, there is some exception for tanks in dedicated arrays that buys them ten year hydros.
I am trying to recall if DOT regs require 5 year hydros, not coming to me. My best guess is a tank destined for an array will, by definition, be shipped empty and not subject to DOT regulation as a pressure vessel. Therefore if it is filled to a pressure for transport it is by definition a stand alone pressure vessel and would require (per DOT) a 5 year hydro. I think.
I wonder what a nitrous fill would cost on my doubled Faber 104s:gr_devil:
EDIT: The DOT regs do address the subject as pressurized volume per container and pressuirzed volume per vehicle. For instance you can put 27 full scuba tanks (Aluminum, 80 cubic feet each) in a 15 passenger van, no permit required. If you want to put in tank #28 you are supposed to get a permit. I am not sure of the low end of the regs, but if I was running nitrous my tank would be big enough to require, and have, a five year hydro.