|Boiler drum and
other cylindrical components having internal diameters greater than 600
mm shall be hydraulically tested on completion of manufacture
at the makers works in the presence of Inspecting
Officer to 1½ times the maximum working pressure
without indication of weakness and defects.
||All components which
are not reasonably accessible for inspection after assembly
into the boiler or have been tested hydraulically prior
to welding at a pressure less than that specified in sub-regulation
(a) shall be tested hydraulically to 1½ times the
maximum working pressure before assembly into the boiler.
that have been hydraulically tested to the required pressure
prior to welding or ultrasonically tested shall not require
further hydraulic testing as components provided they
were joined during assembly by circumferential butt joint
which have been welded and non-destructively tested as
per relevant provisions of these regulations.
than tubular products shall not require hydraulic testing
before assembly into the boiler if the completed boiler
is tested hydraulically to 1 ½ times the maximum
permissible working pressure at site.
||In case of drums,
headers which are to be fitted with tubes, the test may
be made before drilling of tube holes but after attachments
of nozzles and similar fittings.
||The test pressure
shall be raised gradually under proper control at all
times so that it never exceeds by more than 6% of the
required pressure and maintained for 30 minutes whereupon
the pressure shall be reduced to maximum allowable working
pressure and maintained for sufficient time to permit
close visual inspection for leakage of the pressure parts.
of water used as medium of pressure testing shall not
be less than 20°C and more than 50°C.
|| In case of drums
of composite construction and partly riveted
and partly welded seams or seamless forged drum shell
with ends attached by fusion welding, the test pressure
shall be the same as for fusion welded drums.
||Should the hydraulic
test reveal any defects in the welded steam, it shall
not be repaired unless the Inspecting Authority permits
to do so.
||On completion of
agreed repairs to a drum which has previously been stress
relieved by heat-treatment, further heat-treatment, if
required by the Inspecting Authority, shall be done and
the drums shall again be subjected to hydraulic test.".