12.2.1 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 is practicable, the pipes are to be selected for
examination and hydraulic test in rotation so that in the course of
the surveys all sections of the pipeline will be tested.
12.2.2 Where
main and/or auxiliary steam pipes of the category described in Vol 1, Pt 1, Ch 3, 12.2 Scope of surveys 12.2.1 and Vol 1, Pt 1, Ch 3, 12.2 Scope of surveys 12.2.1.(b) have welded joints between
the lengths of pipe and/or between pipes and valves, the lagging in
the way of the welds is to be removed, and 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.
12.2.3 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 smokeboxes are, at the surveys required by Vol 1, Pt 1, Ch 3, 12.1 Frequency of survey to be included in the pipes
selected for examination and testing as defined in Vol 1, Pt 1, Ch 3, 12.2 Scope of surveys 12.2.1. Where the saturated steam
pipes inside the smoke boxes consist of steel castings of substantial
construction, these requirements need only to 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.
12.2.4 At
the surveys specified in Vol 1, Pt 1, Ch 3, 12.1 Frequency of survey 12.1.3,
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.
12.2.5 Where
it is inconvenient for the Owner to fulfil all the requirements of
a Steam Pipe Survey at its due date, LR will be prepared to consider
postponement of the survey, either wholly or in part.