INDIAN BOILER REGULATION 1950
Reg. 376 - Preparation for Inspection
a) At every
examination of boiler or the grant of renewal of a certificate, the boiler
shall be empty and thoroughly clean in all its parts. Except as provided as for
in sub-regulation (f) all doors of manholes, hand holes and sight holes and
cleaning plugs and all caps in the leaders and mud drums of water tube boilers,
all fire bars, bearers, front plates, bridge plates, fire bridges brick arches,
oil fuel burners and mechanical stoker fittings shall be removed. All valves
and cocks comprising the boiler mounting shall be opened up and taken apart and
the valves or cocks ground, when necessary, before the Inspectors’ visit.
b) Provision
shall if, required by the Inspector, be made for the removal of lagging or
brick-work or other concealing part and for the drilling of plates, and for
verifying the pressure gauge and safety valve dimensions and weights.
c) All smoke
tubes, exterior of water tubes, smoke boxes, and external flues shall be swept
clean.
d) Provision
shall be made for the effective disconnection of all steam and hot water
communication with another boiler under steam as required in Chapter IX-A of
these Regulations
e) No blank
flange/plug shall be inserted between a safety valve chest and the boiler
generally and where it is permitted by the Inspector, the blank flange/plug
shall be removed in his presence.
f) At
alternative annual inspections and subject to a minimum of three bottom rows or
all tubes subject to the first pass of heat being opened up for inspection the
Inspector may at his discretion relax the preparation for inspection called for
under (a) above in favor of boilers having an evaporative capacity of 200,000
lbs. per hour and over, and fed either water treated to the satisfaction of the
Inspectors.
g) In the
case of forced flow and forced circulation types of boilers, provisions shall
be made for checking that proper circulation is maintained through all sections
of the circuit by the flow of water.
* Note:- In accordance with section 7
and 8 of the Act, Inspectors are required to measure and examine boilers for
registration, to examine boilers for renewal certificates, to determine subject
to the approval of the Chief Inspector, the pressure at which they may be
allowed to work, to grant certificate therefor and generally to convey to the
owners such orders as the Chief Inspector may issue.
Reg. 377 - Hydraulic test of boilers for registration
Every boiler shall be hydraulically tested in the
presence of an Inspector.
Reg. 378 - Preparation for hydraulic tests
a) The chest
of all mountings subject to the steam pressure shall be in place and shut tight
or blank flanged.
b) The
safety valves should invariably be removed and the chest opening blank flanged.
c) The
attachment for the Inspector’s pressure gauge shall be in order.
d) All doors
shall be properly jointed and tightened up. The boiler shall be completely
filled with water, care being taken to allow all air to escape and, if
possible, a preliminary test not exceeding the working pressure of the boiler
shall be taken before the Inspector’s visit, to test the tightness of the
joints.
e) When a
boiler is hydraulically tested for the first time, it shall be entirely cleared
of lagging or brickwork; at subsequent tests the lagging or brickwork, or portions
thereof, shall be removed if required by the Inspector.
Provided that the Inspector may, at his discretion, allow
the lagging and brick work to remain in situ, in case of boilers where the
covered parts have been fabricated and tested before erection in position.
Reg. 379 - Procedure of hydraulic tests
a)
(i) Subject
to the provisions of sub-regulation (e) of regulation 381, every boiler shall
be hydraulically tested after erection at site in presence of the Inspector to
1¼ times the maximum working pressure as certified by the Inspecting Authority
in Form II, to be stamped on the boiler, as free from any indication of
weakness or defects.
(ii) If all
components of the boiler in the manufacturer’s premises have not been tested
hydraulically as per regulation 268, the test, on completion, shall be taken to
1½ times the maximum working pressure.
(iii) The
temperature of the water used as medium of pressure testing shall not be less
than 20°C and greater than 50°C.
(iv) 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 pressure parts.
b) The
boiler shall satisfactorily withstand such pressure without appreciable leakage
or undue deflection or distortion of its parts for at least ten consecutive
minutes. If the test is not satisfactory, the working pressure allowable by
calculation shall be suitably reduced, unless the owner desires to make such
alterations as will enable the boiler to withstand satisfactorily the hydraulic
test, in which case the boiler shall again be examined after the alterations
have been made, the pressure recalculated, if necessary, and the boiler tested
to the satisfaction of the Inspector.
c) * At the
first hydraulic test of a boiler prior to the issue of an original certificate
deflection measurements shall be made before, during and after test of each
furnace length, fire-box and flat end or other plates.
d) After the
application of the hydraulic test the Inspector shall carefully examine the
boiler inside and outside and satisfy himself that it has satisfactorily
withstood the test.
e) In any
case in which the safe working pressure to be allowed for a boiler cannot,
owing to peculiar construction of any of its parts, be determined by
calculation in the ordinary way, the Inspector shall, under the direction of
the Chief Inspector, subject the boiler to hydraulic test for the purpose of
determining the fitness of such parts. The amount of the test pressure to be
applied in such a case shall not exceed the test pressure prescribed for the
least working pressure found by calculation for other parts of the boiler or
the intended working pressure whichever is less.
f) Should
any part of the boiler show undue deflection or indication of permanent set
during the progress of the test, the pressure shall be released immediately
such indications are observed. The working pressure for the part shall be 40
per cent of the test pressure applied when the point of permanent set was
reached. This procedure shall apply to any boiler at any test.
g) Hydraulic
tests of boilers at subsequent examination shall, except when the Inspector
expressly requires otherwise, be made after the inspection. The test pressure
to be applied to boilers at such subsequent examinations shall be from one and
a quarter to one and a half times the working pressure of the boiler.
h) When the
internal construction of size of a boiler does not permit of the Inspector
getting inside it or of examining closely all its parts, he shall see it tested
by hydraulic pressure to one and a half times the working pressure at each
inspection or the grant or renewal of a certificate.
i) Water
tube locomotive type and all tubular boilers shall be hydraulically tested at
each inspection for the grant or renewal of a certificate, unless such test is
waived under the order of the Chief Inspector.
j) The
Inspector may if the considers it necessary, apply a hydraulic test to any
boiler at any inspection.
k) Except in
the case of vertical boilers, heating surface of which is less than 18.58 sq.m.
(200 sq. ft.), portable and vehicular boilers, which do not require re-erection
or building in brickwork, the hydraulic test of all boiler shall be conducted
only after the erection of the boiler in situ and all boilers shall after
re-erection in a position different from that in which they were last examined
be hydraulically tested.
* NOTE:-These deflection measurements should be entered
in the Memorandum of Inspection Book before its submission to the Chief
Inspector.
l) A
hydraulic test shall also be taken before granting an increased pressure
certificate and after repairing a boiler. However, in the case of minor repairs
to the Water Tube boilers where NDT has been carried out, hydraulic testing may
be dispensed with provided NDT is carried out by an approved method.
m) When carrying out hydraulic test, Inspectors shall use pressure gauges supplied by the Chief Inspector.
a) Every
newly registered boiler and every other boiler of which the working pressure
has been altered shall, before the issue of an original or renewal certificate
for such boiler, be tested under steam to the satisfaction of the Inspector.
b) at the
time of test the safety valves shall be left free and capable of being adjusted
to the approved working pressure.
c) After
adjustment of the valves to the correct blowing pressure the boiler shall be
tried under full steam and firing with the feed water shut off and the
stop-valve closed, during which time the Inspector shall note the accumulation
of pressure and other details of the test as well as the loading and adjustment
of the safety valves.
In the case of water tube boiler or boilers fitted with
super heaters, the feed water connection and stop valve need not be shut off
and if the total safety valve are is lifted and found to be adequate by
calculations, the requirement of the accumulation test may be assumed to have
been satisfied if the valves are or have been found so adjusted that at least
one safety valve on each boiler shall lift at or below the designed working
pressure of the boiler and all valves shall lift so that all steam which can be
generated by the boiler can be discharged with a pressure rise not exceeding
10% of the designed working pressure.
d) Before
the safety valve test, the Inspector shall satisfy himself that the water
gauges are in working order and that the feed apparatus is capable of supplying
the boiler with sufficient water.
e) Where the
State Government does not require a person-in-charge of a boiler to hold a
certificate of competency, the Inspector may, when he thinks fit, satisfy
himself by questioning or by practical test whether the person-in-charge of the
boiler understands the use and purpose of the water gauges, the pressure gauge,
the safety valves, the feed water-supply and blow down.
f) When
witnessing safety valve test, Inspectors shall use the standard pressure gauges
supplied by the Chief Inspector unless the boiler pressure gauge has, since the
time of inspection, been tested and found correct with an authorized testing
machine.
NOTE:- A steam test is primarily intended for the purpose
of ascertaining by actual test whether the safety valves are sufficient to
reliever boilers effectively of excess steam and whether they operate at the
time when the maximum working pressure is reached. Inspectors should always
send to the owner due notice of the date fixed for the steam test.
On completion of the test the Inspector should enter all
details in the Memorandum of Inspection Books.
g) No steam
gauge shall be used without a syphon filled with water between it and the
boiler.
h) When the
accumulation of the maximum working pressure, the area of the safety valves
shall be considered insufficient, and a certificate shall be refused until the
safety valve area is increased.
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