|(a) Valves shall be installed to prevent leaking or
malfunction due to freezing. Cryogenic liquid valves shall be installed
at an angle greater than 45 degrees from horizontal.
(b) Isolation valves shall be provided on container,
tank, and vessel connections, except for connections:
(1) for relief valves. Shutoff valves are only permitted
at connections for relief valves in accordance with ASME Code, Section
VIII, Division 1, Paragraphs UG-125(d) and Appendix M, Paragraphs
M-5 and M-6;
(2) for liquid level alarms required by §14.2501
of this title (relating to Liquid Level Gauging); or
(3) that are blind-flanged or plugged.
(c) Shutoff valves shall be located inside the impounding
area as close as practicable to the containers, tanks, and vessels.
(d) Internal valves shall be designed and installed
so that any failure of the nozzle will be downstream of the seat of
the internal valve itself.
(e) The number of shutoff valves installed shall be
kept to the minimum required for efficient and safe operation of each
(f) Piping systems shall be designed to limit the contained
volume that could be discharged in the event of a piping system failure.
Sufficient valves which can be operated both at the installed location
and from a remote location to shut down the process and transfer systems
in the event of an emergency shall be installed.
(g) Container connections larger than one-inch pipe
size through which liquid can escape shall be equipped with:
(1) a valve which closes automatically if exposed to
(2) a remotely controlled, quick-closing valve which
shall remain closed except during the operating period;
(3) a fail-closed valve; or
(4) a check valve on filling connections.
(h) ESD valves shall be single-purpose valves.
(i) Valves and valve controls shall be designed to
permit operation under icing conditions, if such conditions are possible.
(j) Powered controls shall be provided for emergency
shutoff valves that would require excessive time to manually operate
during an emergency or if the valve is eight inches or larger in size.
A means for manual operation shall also be provided.