John Fox
Guest
I had the same situation recently. I ended up with a set of doubles dated in the 40s before there was scuba. Tanks were marked USN. They had 1" NPT threads, bushed to 1/2" with USD manifold with no burst discs.(also now illegal). Remember that the military is not supject to DOT rules, or was not in the past. They now require that tanks be DOT marked. I have a set of Navy doubles dated 1967 without DOT or ICC stamp which can neither be tested or filled legally in civilian life. Hydro shop said he could not legally hydro them with the bushings or fill them with the bushings. I remember in the 60s that bushings were common as guys often used bushed cylinders made from old bailout bottles or fire extinguishers(CO2) which were usually 1800 psi. I remember reading that some early USD tanks came from the factory bushed. IDK if that is true or not. The tanks can legally be hydroed and filled, but with a 1" valve only, bushings removed. Now in this configuration they are not much use for diving without adapters, which just aint worth the trouble. There are easier, cheaper ways. As far as safety of old tanks: if they pass visual and hydro, use them. I have seen oxygen tanks made in 1917 still in use. John
