d) Use carbon steel shells designed for a minimum
175 psig (1210 kPa) cold working pressure on both steam and
e) Do not exceed 0.2 psig (1.4 kPa) for the pressure
drop on the oil side of pump suction line nor exceed 10 psig
(70 kPa) of pressure drop for heaters installed on pump
Insulation and Tracing. In cases where fuels are
heated, examine the possible economic incentives for
insulating heated storage vessels and piping. In many cases,
piping carrying heated products must be heat traced to prevent
possible solidification of the fuel during a shutdown period.
Insulate traced lines. Consider possible incentives for
installing a condensate collection and return system. If a
condensate return system is installed, include a monitor to
detect oil in the condensate.
General Design Considerations. Provide diked
enclosures to prevent spilled petroleum from leaving the
property for all aboveground tanks. Provide drainage
structures to impound escaping fuel where rupture of an
underground tank in a hillside location would endanger other
activities and structures at elevations lower than the tank.
Subdivide each diked area containing two or more tanks by
intermediate curbs to prevent spills from endangering adjacent
tanks within the diked area. Designer can take advantage of
the exception granted for concrete-encased tanks by NFPA 30 or
NFPA 30A if the provisions of that document are met and local
and state regulations permit.
Capacity. Comply with NFPA 30 for capacity of diked
enclosures except where NFPA 30 makes reference to volumetric
capacity of tank or tanks, add volume for 5-year, 1-hour
duration storm or one foot (0.3 m) freeboard, whichever is
greater. Use local or state criteria if they are more
stringent. Individual tanks larger than 10,000 barrels (1600
m3) in capacity should be enclosed in an individual dike.
Groups of tanks with 10,000 barrels (1600 m3) or less capacity
and not exceeding 15,000 barrels (2400 m3) in aggregate
capacity may be enclosed in a single dike. When subdividing
is required, use intermediate dikes not less than 18 inches