DIN 477-7
DIN 477-7 Gas cylinder valves for cylinder test pressures up to 300 bar - Part 7: Gauges for tapered thread W 31.3 × 1/14 (acetylene)
standard by Deutsches Institut Fur Normung E.V. (German National Standard), 05/01/2014
standard by Deutsches Institut Fur Normung E.V. (German National Standard), 05/01/2014