16.2.1 At
each survey, a selected number of main steam pipes, also of auxiliary
steam pipes, which:
-
are over 76 mm
external diameter,
-
supply steam
for essential services at sea, and
-
have bolted joints,
are to be removed for internal examination and are to be hydraulically
tested to 1,5 times the working pressure. If these selected pipes
are found satisfactory in all respects, the remainder need not be
tested. So far as practicable, the pipes are to be selected for examination
and hydraulic test in rotation, so that in the course of surveys all
sections of the pipeline will be tested.
16.2.2 Where
main and/or auxiliary steam pipes of the category described in Pt 1, Ch 3, 16.2 Scope of surveys 16.2.1 and Pt 1, Ch 3, 16.2 Scope of surveys 16.2.1.(b) have welded joints between
the lengths of pipe and/or between pipes and valves, the lagging in
way of the welds is to be removed, and the welds examined and, if
considered necessary by the Surveyor, crack detected. Pipe ranges
having welded joints are to be hydraulically tested to 1,5 times the
working pressure. Where lengths having ordinary bolted joints are
fitted in such pipe ranges and can be readily disconnected, they are
to be removed for internal examination and hydraulically tested to
1,5 times the working pressure.
16.2.3 Where,
on cylindrical boilers having smoke tube superheaters, the saturated
steam pipes adjoining the saturated steam headers are situated partly
in the boiler smoke boxes, all such pipes adjoining and cross−connecting
these headers in the smoke boxes are, at the surveys required by Pt 1, Ch 3, 16.1 Frequency of surveys, to be included in the pipes
selected for examination and testing, as defined in Pt 1, Ch 3, 16.2 Scope of surveys 16.2.1. Where the saturated steam
pipes inside the smoke boxes consist of steel castings of substantial
construction, these requirements need only be applied to a sample
casting. Where steel castings are not fitted, the Surveyor is to satisfy
himself of the condition of the ends of the saturated steam pipes
in the smoke boxes at each Boiler Survey and, if he considers it necessary,
a sample pipe is to be removed for examination.
16.2.4 At
the surveys specified in Pt 1, Ch 3, 16.1 Frequency of surveys 16.1.3,
any of the copper or copper alloy pipes, such as those having expansion
or other bends, which may be subject to bending and/or vibration,
also closing lengths adjacent to steam-driven machinery, are to be
annealed before being tested.
16.2.5 Where
it is inconvenient for the Owner to fulfill all the requirements of
a Steam Pipe Survey at its due date, the Committee will be prepared
to consider postponement of the survey, either wholly or in part.