(1) All appurtenances shall be designed for not less than the maximum working
pressure of that portion of the system on which they are installed. All
appurtenances shall be fabricated from materials suitable for use in anhydrous
(2) All connections to containers, except safety relief connections and
gauging devices, shall have shutoff valves located as close to the container as
(3) Liquid level gauging devices, which are so constructed that outward flow
of container content shall not exceed that passed by a No. 54 drill size
opening, need not be equipped with excess flow valves.
(4) Container openings or through fittings (directly on container and used for
pressure gauge connections) need not be equipped with excess flow valves if
such openings are protected by a vent hole not larger than a No. 54 drill size
(5) All excess flow valves shall be clearly and permanently marked with the
name or trademark of the manufacturer, the catalog number, and the rated
(6) Excess flow valves shall close automatically at the vapor or liquid
rated flows as specified by the manufacturer. The connections and line,
including appurtenances being protected by an excess flow valve, shall have a
greater capacity than the rated flow of the excess flow valve so the valve will
close in case of failure at any point in the line or fittings.
(7) Excess flow and back pressure check valves shall be located inside the
container or at a point outside where the line enters the container. In the
latter case, installation shall be made in such a manner that any undue strain,
beyond the excess flow or back pressure check valve, will not cause breakage
between the container and the excess flow valve.
(8) Excess flow valves shall be designed with a by-pass, not to exceed a No.
60 drill size opening, to allow equalization of pressure.