14.2.1 Expansion
pieces of an acceptable design are only to be used in permanent piping
system installations to accommodate axial and lateral movements. They
are not to be used to compensate for piping misalignment unless specifically
designed for the purpose.
14.2.2 Expansion
pieces are to be used within their specified pressure, temperature
and movement conditions for all normal operating conditions. The design
and operating ratings of expansion pieces are not to be less than
that of the piping system in which the expansion piece is installed.
14.2.3 Expansion
pieces used in compressed air, boiler feed water, steam and flammable
oil piping systems are to be of steel or other approved material.
14.2.4 Expansion
pieces incorporating oil resistant rubber or other suitable synthetic
material may be used in cooling water lines in machinery spaces. Where
fitted in sea-water lines, they are to be provided with guards which
effectively enclose, but do not interfere with, the action of the
expansion pieces and will reduce to a minimum practicable, any flow
of water into the machinery spaces in the event of failure of the
flexible elements. Proposals to use such fittings in water lines in
other services, including, ballast lines in machinery spaces and inside
water ballast tanks, and bilge lines in enclosed spaces only, will
be specially considered when plans of the piping systems are submitted
for approval.
14.2.5 Expansion
pieces are to be installed in accordance with the manufacturer's instructions
and are to be protected against over extension and over compression.
The adjoining pipes are to be suitably aligned, supported and anchored.
Where necessary, expansion pieces of bellows are to be protected against
mechanical damage.