the unloading station, and tank and pipe appurtenances up to the
double block and bleed valve at each building. NFPA 54 covers
any part of the system where the propane gas pressure is less
than 1370 kPa.
d) Fuel should be stored in a single location which
provides easy access for tank trucks. This is to facilitate
inventory taking, reduce installation costs, and increase
safety. Use a minimum of two tanks to store the fuel. This
allows for tank maintenance without interruption to the
training. The total storage should equal 30 days' consumption.
Design a full storage tank to contain 80 percent liquid
equivalent to 30 days' storage and 20 percent vapor. The vapor
space allows for thermal expansion and must never be used for
liquid storage. Fence the storage area to restrict pedestrian
and vehicular traffic. The fence should have a main entrance
gate and a second gate on the opposite fence from such gate for
emergency exit. At fence openings, provide a remote shutoff
station for the emergency shutoff valves, refer to subpar. o).
The fence area should have anti-vehicle barricade posts to
protect tanks from an accidental collisions from vehicles or
trucks. In accordance with NFPA 58, the storage area should not
have walls, barricades, curbed areas, etc., which would prevent
access and lateral ventilation from flushing the area. Provide
the tanks in accordance with the American Society of Mechanical
Engineers (ASME), Boiler and Pressure Vessel Code, Section VIII,
unfired pressure with a minimum working pressure of 2100 kPa.
Propane storage tanks should have an American Society of
Mechanical Engineers stamp of approval on the tanks. No used
tanks are allowed. Tank foundations should be proper for the
soil bearing conditions and the weight of the tank plus its full
weight of water because of the future hydrostatic testing of
each tank. Tank exterior shells should be coated with proper
corrosion protective material where the tank shell rests on the
foundation. This may be accomplished with a properly saturated
pad. The tank should be adequately grounded.
e) The tank valves and other appurtenances should be
listed and approved for LP gas use by Underwriters Laboratories,
Inc. (UL), Factory Mutual Research Corporation (FM), or other
should be in accordance with the specifications of UL or ASME.
The vent outlet from such valves should be a minimum of 2150 mm