Materials of Construction. Use carbon steel or
nodular iron bodies and bonnets for all pipeline valves. Do
not furnish nor install cast iron or bronze-bodied valves in
liquid petroleum service.
opening or closing is required. Require synthetic seals or
seating material of Teflon or viton. Use valves that are
designed so that if synthetic seating material is burned out
in a fire exposure, a metal-to-metal seat will remain to
affect closure and comply with API Std 607. Where line
pigging is required or if within ten pipe diameters upstream
such as venturis, use full port ball valves. Valves should
comply with API Std 608.
b) Use check valves to prevent backflow through
branch lines, meters, or other locations where runback or
reverse flow must be avoided. Check valves may be of the
swing disk, spring-loaded poppet, or ball types. Use swing
checks of soft-seated non-slamming type with renewable seats
and disks. Conform check valves to API Spec 6D.
c) Use lockable, double-seated, tapered lift plug
valves with an automatic body bleed between the seats (double
block and bleed) for separation of product services, when
piping goes above or below ground, between pier and tank
storage, and other locations critical to pressure-testing of
piping. Do not use lubricated plug valves.
Valve Operators. Provide manually operated valves
Use geared operators for gate valves larger than 6 inches (150
mm). Use geared operators for ball and plug valves larger
than 6 inches (150 mm). Gate, ball, and plug valves specified
for remote, automatic, or emergency service may have electric
motor operators with suitable torque limiting controls if