WAC 296-307-44005. Valves and accessories

(1) A filling connection on the container must be fitted with one of the following: (a) A combination back-pressure check and excess flow valve. (b) One double or two single back-pressure valves. (c) A positive shut-off valve, in conjunction with either: (i) An internal back-pressure valve; or (ii) An internal excess flow valve. Instead of an excess flow valve, filling connections may be fitted with a quick-closing internal valve that only opens during operating periods. The mechanism for such valves may have a secondary control that will close automatically in case of fire. The melting point for a fusible plug must be a maximum of 220°F. (2) A filling pipe inlet terminal off the container must have a positive shut-off valve and either: (a) A back pressure check valve; or (b) An excess flow check valve. (3) All openings in the container must have approved excess flow check valves. Exceptions: (a) Filling connections; (b) Safety-relief connections; (c) Liquid-level gauging devices; and (d) Pressure gauge connections. (4) All container inlets and outlets must be labeled to designate whether they connect with vapor or liquid (labels may be on valves). Exceptions: (a) Safety-relief valves; (b) Liquid-level gauging devices; and (c) Pressure gauges. (5) Each storage container must have a suitable pressure gauge.