(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.

(4) All container inlets and outlets must be labeled to designate whether they connect with vapor or liquid (labels may be on valves).

(5) Each storage container must have a suitable pressure gauge.