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CHAPTER - 22
Indian Boiler Regulation
Indian Boiler Regulation:

IBR is Indian Boiler Regulations, which was created in 15th September 1950 in exercise
of the powers conferred by section 28 & 29 of the Indian Boilers Act. The Indian
Boilers Act was formed in 1923, 23rd February to consolidate and amend the law
relating to steam boilers
Steam boilers and steam pipes:
Steam boiler:
Steam boilers under IBR means any closed vessel exceeding 22.75 liters in capacity
and which is used expressively for generating steam under pressure and includes any
mounting or other fitting attached to such vessel which is wholly or partly under
pressure when the steam is shut off.
Steam pipes:
IBR steam pipe means any pipe through which steam passes from a boiler to a prime
mover or other user or both if pressure at which steam passes through such pipes
exceeds 3.5 kg/cm2 above atmospheric pressure or such pipe exceeds 254 mm in
internal diameter and includes in either case any connected fitting of a steam pipe.

THE INDIAN BOILERS (AMENDMENT) ACT, 2007

Some of the significant Changes:

The definition of “boilers”:

In new act it is a pressure vessel in which steam is generated for use external to itself
by application of heat which is wholly or partly under pressure when steam is shut off
but does not include a pressure vessel :
a) with capacity less than 25 litres (such capacity measured from the feed check
valve to main steam stop valve)
b) with less than one kilogram per centimeter square design gauge pressure and
working pressure
or
c) in which water is heated below one hundred degree centigrade.

The definition of “Steam Pipe”:

In old act it is a pipe line through which steam passes from boiler to a prime mover or
other user or both. Of course there were limitations to pressure or diameter (3.5 kg/
cm2 and 250 NB).
In new act, it means any pipe through which steam passes. The pressure and diameter
limitation will be there.

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Introduction of third party inspecting bodies besides Boiler Directorate:

i) Competent Person
ii) Competent Authority
iii) Inspecting Authority

Periodicity of certificate issued to boiler users after carrying out statutory

inspection.
Till now the certified period to use the boilers was for twelve months whatever may
be the size and running condition of boilers.
Now it will vary from 12 months to 48 months depending upon various factors to be
outlined by the Indian Boiler Regulation.

Stricter penal measures:

The new act has introduced heavy penalty for various offences
For running of boilers without certificate there was a fine of five hundred rupees
earlier, now it has become one lakh rupees.

In section 24 for other penalties like

a) Failing to engrave the registration number
b) Illegal repairs
c) Fails to report accident
d) Tempering with safety valves
e) Allowing any person to go inside boiler without effective disconnection
In old act it was a fine of five hundred rupees. Now it is revised to “punishable with
imprisonment which may extend to two years or with fine which may extends to one
lakh rupees or with both.
In section 25 for offence of tempering registration mark, the fine may extends to one
lakh rupees

Procedure for Registration of a new Boiler:

[ As per section 7 of Indian Boiler Act, 1923 ]
1) The owner of any boiler which is not registered under the provisions of this Act
may apply to the inspector to have the boiler register. Every such application shall be
accompanied by prescribed fee.
2) On receipt of an application under subsection (1),the inspector shall fix a date,
within thirty days or such shorter period as may be prescribed from the date of the
receipt, for the examination of the boiler and shall give the owner there of not less
than ten days notice of the date so fixed.
3) On the said date the inspector shall proceed to measure and examine the boiler
and to determine in the prescribed manner the maximum pressure. If any , at which
such boiler , may be used, and shall report the result of the examination to the Chief
Inspector in the prescribed from.
4) The Chief Inspector, on receipt of the report, may

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a) Register the boiler and assign a register number thereto either forthwith or
after satisfying himself that any structural alteration, addition or renewal
which he may deem necessary has been made in or to the boiler or any steam-
pipe attached, or
b) Refuse to register the boiler:
Provided that where the Chief Inspector refuses to register a boiler, he shall
forthwith communicate his refusal to the owner of the boiler together with the
reasons therefore.

5) The Chief Inspector shall, on registering the boiler, order the issue to the owner
of a certificate in the prescribed form authorising the use of the boiler for a period
not exceeding twelve months at a pressure not exceeding such maximum pressure as
he thinks fit and as is in accordance with the regulations made under this Act:

6) The Inspector shall forthwith convey to the owner of the boiler the orders of the
Chief Inspector and shall in accordance therewith issue to the owner any certificate
of which the issue has been ordered, and, where the boiler has been registered, the
owner shall within the prescribed period cause the register number to be permanently
marked thereon in the prescribed manner.

Procedure for Renewal of Certification:

1) A certificate authorising the use of a boiler shall cease to be in force

a. On the expiry of the period for which it was granted, or

b. When any accident occurs to the boiler, or

c. When the boiler is moved (excluding vertical boilers with heating surface less
than 200 sq.ft., (portable boilers or vehicular boilers), or

d. When any structural alteration, addition or renewal is made in or to the boiler,

or

e. If the Chief Inspector in any particular case so directs when any structural
alteration, addition or renewal is made in or to any steam pipe attached to the
boiler, or

f. On the communication to the owner of the boiler of an order of the Chief

Inspector or Inspector prohibiting its use on the ground that it or any steam
pipe attached thereto is in a dangerous condition.

2) Where an order is made under Clause (f) of Sub Section (1) the grounds on
which the order is made shall be communicated to the owner with the order.

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3) When a certificate ceases to be in force the owner of the boiler may apply to
the Inspector for a renewal thereof for such period not exceeding twelve
months as he may specify in the application.
[Provided that where the certificate relates to an Economiser or an unfired boiler
which forms an integral part of a processing plant in which steam is generated solely
by use of oil, asphalt or bitumen as a heating medium, the application for its renewal
may be for a period not exceeding twenty-four months.]

4) An application under Sub Section (3) shall be accompanied by the prescribe

fee and, on receipt thereof, the Inspector shall fix a date, within thirty days or such
shorter period as may be prescribed from the date of the receipt, for the examination
of the boiler and shall give the owner thereof not less than ten days notice of the
date so fixed. Provided that, where the certificate has ceased to be in force owing to
the making of any structural alteration, addition or renewal, the Chief Inspector may
dispense with the payment of any fee.
[Provided further that in the case of an Economiser or an unfired boiler which forms
an integral part of a processing plant in which steam is generated solely by use of oil,
asphalt or bitumen as a heating medium, the date fixed for its examination shall be
within sixty days from the date of the receipt of the application and the owner shall
be given not less than thirty days notice of the date so fixed.]

5) On the said date, the Inspector shall examine the boiler in the prescribed manner
and if he is satisfied that the boiler has a steam pipe or steam pipes attached thereto
are in good condition shall issue a renewed certificate authorising the use of the
boiler for the specified period at a pressure not exceeding such maximum pressure as
he thinks fit and as is in accordance with the regulations made under this Act.

[Provided that renewed certificate issued under this subsection in respect of an

Economiser (or of an unfired boiler which forms an integral part of a processing plant
in which steam is generated solely by use of oil, asphalt or bitumen as a heating
medium) may authorise its use for a period not exceeding twenty four months]

Provided further that if the Inspector -

1) Proposes to issue any certificate -
a) Having validity for a less period than the period entered in the application or
b) Increasing or reducing the maximum pressure at which the boiler may be used
or
2) Proposes to order any structural alteration, addition or renewal to
be made in or to the boiler or to any steam pipe attached thereto or

3) Is of opinion that the boiler is not fit for use the Inspector shall
within 48 hours of making the examination inform the owner of the boiler in
writing of hid opinion and the reasons therefore and shall forthwith report the
case for orders to the Chief Inspector.

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4) The Chief Inspector, on receipt of a report under Sub Section(5), may, subject to
the provisions of this Act, and of the regulations made thereafter, order the
renewal of the certificate in such terms and on such conditions, if any, as he
thinks fit, or may refuse to renew it:
[Provided that where the Chief inspector refuses to renew a certificate, he shall
forthwith communicate his refusal to the owner of the boiler, together with the
reasons therefore.]

5) Nothing in this section shall be deemed to prevent an owner of a boiler from

applying for a renewed certificate therefore at any time during the currency of a
certificate.

Authority for Second class boiler competency certificate holder:

Second class boiler competency (Attendant) certificate holder is authorised to have
charge of a single boiler of any type the heating surface of which does not exceed 240
sq.mtrs. He may, however, attend to a battery of boilers (max. three) and aggregate
heating surface not exceeding 140 sq. mtrs., provided he is assisted by fireman. (No.
of fireman required as per consideration of chief Inspector).

Authority for First class boiler competency certificate holder:

First class boiler attendant is authorised to have charge of single boiler of any type or
capacity or two or more boilers in a battery or separate, the total heating surface of
which does not exceed 700 sq. mtrs. Provided that such boilers shall be situated
within a radius of 23 mtrs in the same premises and belong to same owner and then
he is assisted by necessary second class boilers attendants.

Authority for First class boiler proficiency certificate holder:

Second class boiler proficiency engineer is authorized to hold charge of a single boiler
of any type, or capacity or battery of boilers within radius of 23 mtrs. under same
premises of same owner.

Report of accidents:
(1) If any accident occurs to a boiler or steam-pipe, the owner or person in charge
thereof shall, within twenty-four hours of the accident, report the same in writing to
the Inspector. Every such report shall contain a true description of the nature of the
accident and of the injury, if any, caused thereby to the boiler or to the steam-pipe
or to any person, and shall be in sufficient detail to enable the Inspector to judge of
the gravity of the accident.

(2) Every person shall be bound to answer truly to the best of his knowledge and
ability every question put to him in writing by the Inspector as to the cause, nature or
extent of the accident.

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Requirement of mountings, fittings & auxiliaries for a boiler as per IBR:
As per the regulation no. 281 every boiler shall be provided at least with the
following:-
Two safety valves, one of which may be a high steam and low water type safety valve.
In no case should the bore of the seat of the valve be less than 19 mm (3/4”).
Two means of indicating the water level:
A steam pressure gauge;
A steam stop valve;
A feed check valve;
One feed apparatus. When the heating surface exceeds 200 square feet – two
independent feed apparatus, each such apparatus shall have a capacity of not less
than the maximum continuous rating of the boiler. In the case of a battery of boilers
connected to a common feed range, this requirement in respect of the number of
feed apparatus shall be considered to have been fulfilled provided a total supply of
feed water, not less the combined maximum continuous rating of all active boilers
can be maintained even if any one of the sources of power supply should fail.
A blow-down cock or valve;
A fusible plug when boiler has internal furnaces;
An attachment for Inspector’s test gauge;
A manhole, where size and construction permit and such mudholes or sight holes as
are necessary for effectively cleaning the boiler.
In the case of boiler fitted with integral superheaters, an additional safety valve shall
be fitted at the end of the superheater outlet header.
It is recommended that in Lancashire and Cornish Boilers, one of the safety valves
should be of high steam and low water type. In Water Tube and Horizontal Multi-
tubular Boilers, a low water alarm directly operated by steam should be fitted. Rams-
bottom type safety valves consisting of two valves and with spring and lever in
common may be considered as two safety valves for the purpose of this Regulation.
In the case of automatic or semi-automatic oil-fired or gas-fired boilers, low water
alarm may be fitted in place of a fusible plug provided such boilers are equipped with
automatic tripping device to disconnect fuel supply and to start the feed pump
simultaneously in the event of low water in the boilers.

In the case of miniature boilers, the steam pressure gauge may be connected to the
steam space or to a steam connection to the water column by a siphon tube or
equivalent device that will keep the gauge tube filled with water. If brass or bronze
composition is used the minimum size of the siphon tube shall be 6 mm (1/4 in.)
standard pipe size; for other materials the minimum inside diameter of the pipe or
tube shall be 13 mm (1/2 in.).

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Additional requirement for automatic boilers only as per IBR:
Additional requirements for automatic boilers only[281-A].

General:
Every boiler which is provided with the appropriate water level and/or firing
control, to allow for automatic working, shall comply with the following
requirements:

1) In the event of failure of automatic control, boiler shall be capable of being

brought under immediate manual control.

2) In those cases where the control and alarm devices are housed in chambers
external to the boiler, the following shall apply:

a) The boiler shall have provision made for isolating the steam and water
connections of the chambers from the boiler. Such isolating valves shall be
capable of being locked in the open position and should preferably be of the
parallel slide type but if screw down stop valves are fitted, those on the water
connection shall be mounted with the spindle horizontal to avoid the possibility
of an air lock. The steam and water connections of the chambers shall be not
less than 25 mm bore. In those cases where sequencing control water valves
are fitted, the steam-isolating valve may be omitted;

b) The boiler shall have means provided to test the operation of the control or
alarm and to blow through separately the water connection and the chamber to
prevent the accumulation of deposits. The means provided for flowing through
shall be sequencing valves or equivalent devices so arranged that the water
connection to the boiler cannot be shut off unless the drain connections to the
chamber is open;

c) The boiler shall have a drain system from the chambers which provides a visual
indication of flow. Tundishes of adequate size, placed in a prominent position
shall be used wherever practicable.

3) Where the boiler is provided with electrical equipment for water level and firing
control, it shall have this equipment so designed that any fault in the circuits
caused both in the fuel and air supply the boiler to be automatically shut off.
Positive means requiring manual resetting shall be provided to cut off the fuel and
air supplies to the boiler should there be a failure of electricity supply to water
level and/or firing control equipment. All electrical conductors and equipment in
connection with water level and firing controls shall be of adequate size and shall
be properly insulated and protected against danger including adequate protection
against the ingress of moisture and the effects of high temperature.

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4) Where the evaporating capacity of the boiler is greater than 3700 kg/h., it shall
have automatic water level alarms and firing controls and can be tested regularly
without altering the level of water in the boiler. The water level alarms may be
incorporated in the automatic control system.

5) With a perceptible water level which are arranged for automatic working and not
intended for continuous supervision shall be provided with an entirely independent
and separately operated overriding control in addition to the water level and firing
controls specified in Cls. (2) and (3). The overriding control shall comply with the
following requirements :-

a) Cut off fuel supply to the burners or the fuel and air supply to solid fuel stoker
and operate an audible alarm when the water level in the boiler falls to a pre-
determined low water level;

b) Be of the lock-out type and so arranged that control or its electrical circuit has
to be manually reset before the boiler can be brought back into operation;

c) Be provided with its own entirely independent electrical control circuit.

Where mounted externally to the boiler, the overriding control shall –

be provided with its own chamber;
comply with the requirements of Cl. (b).

Automatic Water level control – Automatic water level controls shall be as follows :
float or displacer operated; or
operated by electrical probe or thermostat; or
operated by other approved principle subject to satisfaction of the Inspecting
Authority.
The control equipment shall regulate the feed-water supply to the boiler in order to
maintain effectively the level of water in the boiler between pre-determined limits.
Automatic firing controls – Automatic firing controls shall comply with the following
requirements :-
At all times they shall control effectively the supply of fuel and air to the combustion
equipment;
They shall shut off the fuel supply to the burners or the fuel and air supply to the
stoker under the following conditions :
Flame failure of pilot flame failure in the cases of gas, oil or pulverized fuel fired
boilers. This control shall be of the lock-out type required to be manually reset;
Failure to ignite the fuel at the burner within a pre-determined time. The control
shall be of the lock-out type required to be manually reset;
When the water level in a boiler with a perceptible water level falls below a pre-
determined safe level. The control shall also cause an audible alarm to sound.
Failure of forced or induced draught fans or any automatic flue damper.
Increase in boiler pressure to a pre-determined value.

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When the outlet steam temperature in a forced flow once-through boiler increases to
a pre-determined value.
NOTE – The above provisions do not apply to once through forced circulation boiler.]

Special requirements for safety valves:

[Cl. 291.] General: Safety valves, ordinary, high lift and full lift, shall be so
constructed that breakage of any part will not obstruct the free and full discharge of
steam from the boiler.
[Cl.292.] Definitions: (a) Ordinary lift safety valve. – A safety valve in which the
valve head lifts automatically a distance of at least D/24 with an over-pressure not
exceeding 10% of the set pressure. There shall not be any mechanical stop which
would prevent the valve head from being lifted a distance of at least D/8. D is the
minimum bore of the body seat.
(b) High lift safety valve. – A safety valve in which the valve head lifts automatically
a distance of at least D/12 with an over pressure not exceeding 10% of the set
pressure. There shall not be any mechanical stop which would prevent the valve head
from being lifted a distance of at least D/8.
D is the minimum bore of the body seat.
(c) Full lift safety valve. – A safety valve in which the valve head lifts
automatically a distance such that the area of discharge which limits the flow through
the valve is between 100% and 80% of the minimum area at any section at or below
the body seat. This lift is achieved by a rapid opening within an over pressure not
exceeding 5% of the set pressure.]
[Cl.293.] Discharge capacity of Safety Valves: (a) Saturated steam. – The rated
discharge capacity of a safety valve which discharges saturated steam shall be
calculated using the following equation.
E = CAP
Eqn. (78)
Where
E = is the rated discharge capacity of saturated steam (Kg/h);
P = is the highest pressure of any safety valve mounted on the boiler (bar absolute);
A = is the area (mm2)
For the ordinary lift and high lift safety valves A is the area of the minimum bore of
the body seat. For full lift safety valves A is the area of discharge described in Cl. (c)
of Regulation 292 and its value can only be obtained from the safety valves
manufactures C is a constant taken from the following table, appropriate to the type
of the valve or as established by tests carried out in accordance with Appendix L.
Type of valve Value of the constant “C”
Ordinary lift 0.05
High lift 0.10
Full lift 0.24
(b) Super-heated steam. – The rated discharge capacity of the safety valve which
discharge superheated steam shall be calculated using the following equation:-

ES = E / √ [(1+2.7 Ts) / 1000]

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Where
ES is the rated discharge capacity of super-heated steam (kg/h);
E is the rated discharge capacity of saturated steam calculated using equation (78)
(kg/h).
T is the degree of superheat 0C.
Equation 79 may be used to determine the rated discharge capacity of safety valves
at upper critical stem pressure. In these cases the saturation temperature of the
steam shall be taken as 3750C.]
(c) The total peak load evaporation of a boiler shall be calculated on the basis of
evaporation not less than 30 kg/hr/m2 of heating surface (exclusive of super-heated
and non-steaming economizer). In the case of Waste Heat Boilers, however, when the
evaporation per square metre of safety valves required by the manufactures to be less
than 30 kg. The minimum number of safety valves required may be calculated on the
basis of the actual maximum evaporation of the boiler.]

[Cl.294.] Over pressure of safety valves: The safety valves shall be so designed that
they attain rated discharge capacity with the over pressure not greater than that
given in Regulation 292; provided that the safety valves which have a discharge area
less than 80 per cent of the flow area, the over pressure at which the design lift is
attained shall not exceed 10 per cent of the set pressure. For safety valves having
discharge area 80 per cent of more of the flow area, the over pressure at which the
design lift is attained shall not exceed 5 per cent of set pressure.
[Cl.295.] Pressure Drop: – The safety valves shall reset at a pressure at least 2.5%
below, but not more than 5% below the safety valve set pressure. The 5% limit is
increased to 10% for valves having a body seat bore less than 32 mm and/ or having a
set pressure of 2 bar gauge or less.]
[Cl.296.] Mounting of safety valves: – (a) Safety valves shall be mounted, without
any intervening valve, on pads or branches used for no other purpose. The axis of the
valve shall be vertical. The cross-sectional area of the bore of each pad or branch
shall be at least equal to the area of the bore at the inlet of the safety valve, or
where two or more safety valves are mounted on the same pad or branch, at least
equal to the sum of the areas of the inlet bores of all the safety valves.
(b) Branches shall be as short as possible so as not to impair action of the safety
valves or impose any undue stress on the branches at their point of attachment to
the boiler. Nothing shall obstruct free flow to the safety valve. Branches, particularly
when full lift safety valves are mounted on them, should be radiused at the inlet. The
inlet and outlet flanges shall be drilled in accordance with approximate table in
Appendix E for the diameters of flanges adopted.]
[Cl.297.] Openings in Shell: – No accessories other than those integral with the
Safety Valves shall obstruct the opening un the boiler shell. Discharging steam shall
have direct access to the safety valve without flowing through internal pipes.
[Cl.298.] Discharge Passage: – The safety valves discharge pipes shall comply with
the requirements of Cls. (a) and (b) of this regulation. The discharge pipe shall be as
short and straight as possible and be fitted with open drain to prevent accumulation

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of water in the pipe. Suitable arrangement shall be provided in the discharge pipe
system so that the discharge can readily be heard by the Boiler Attendant.
(a) Steam safety valves .-
Ordinary and highlift valves – Where a waste steam-pipe s fitted the pipe and the
passage leading to it shall have a cross-sectional area not less than the minimum
combined area of the safety valves required by Regulation 293.
Full in valves – For full lift valves the area of waste steam-pipe and passages lading to
it shall have a cross-sectional area not less than twice A, or such area above this
minimum as may be required for valves having a higher approved constant, where A, E
and P are as defined in Regulation 293.
(b) Economiser safety valves – The area of the discharge pipe from an economizer
safety valves shall be at least twice the area of the valve seating.
Where the discharge from several economizer safety valves is connected to the
main discharge pipe, the diameter of the main discharge pipe shall be designed to
prevent accumulation of pressure due to the formation of steam under the particular
conditions of temperature and pressure which may be applicable.
[Cl.299.] Drainage: - For each enclosed safety valve chest a means of draining shall
be provided. The drain pipe shall be laid with a continuous downward gradient clear
of the boiler to a place where the discharge is visible and cannot do injury to any
person.
[Cl.300.] Moving Parts: – The valves and spindles shall be efficiently guided and
means shall be provided in every case to prevent their lifting out of their guides. The
working parts shall have sufficient clearance to ensure freedom of movement under
all conditions of service. The spindle shall not be fitted with a stuffing box.
[Cl.301.] Bearing for Levers: – The bearing of the levers of lever valves shall be so
designed as to allow free working of the valve under all conditions of service. Where
the lever is mounted on pin bearings, the holes in the lever shall be bushed with non-
corrodible metal, or the pins shall be of non-corrodible metal.
[Cl.302.] Attachment of Weight and Springs: - (a) In a lever and weight safety valve
the weight shall be in one piece and attached to the lever in such a way that the
safety valve cannot be overloaded.
(b) In the case of spring loaded safety valves, washers or ferrules shall be fitted
under the adjusting screws so that the valves cannot be overloaded when under
steam.
[Interference with load on the spring, after the safety valve ahs been adjusted,
shall be prevented by fitting of a ferrule under the adjusting screw collar, or by using
a lock nut on the adjusting screw which shall be further safe-guarded by means of a
padlock or other suitable device.] Where springs are in tension, links or other suitable
stops shall be fitted to prevent the spring being extended a greater amount than that
corresponding to a valve lift to D/4 where D is the diameter of valve seating.]
[Cl.303]. Easing Gear: – Safety valves shall be so arranged that they can be based off
their seats when under pressure and the easing lever shall positively lift the valve.
[Cl.304.] Lift: – Safety valves shall be capable of being lifted a distance such that the
area of the discharge edge shall not be less than the minimum aggregate area, A in
Reg. 293.

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Preparation of a boiler for inspection:

The preparation for annual statutory inspection is mainly consisting of gradual cooling
and opening up of the boiler and thorough cleaning of the fire side and water side
surfaces.
If possible the boiler is allowed to cool down naturally and the water is removed only
after the brickwork is sufficiently cooled to avoid any damage to the boiler due to
temperature differentials.
If the Boiler under inspection is working in battery with other boilers, it must be
effectively disconnected of all steam and hot water communications with other
boilers under steam. Effective disconnection shall be made either by removal of the
boiler stop valve or of a length of piping, or by the insertion of substantial blind
flanges between the boiler stop valves and piping.
Remarks mentioned in the certificate of the Boiler issued by the Government
Inspector should be carefully perused and if there are any requirements for removal
of lagging, brickwork etc. are mentioned, then the same should be complied with.
Water must be drained through blow down system.
After the boiler has cooled man hole covers of the main drum must be opened first. If
the bottom man hole covers are opened first there is likelihood of injury to personnel
due to escaping steam or hot air.
All doors of man, mud and sight holes, cleaning plugs, all caps of headers and mud
drums, fire bars and their bearers, fire bridge arches, oil or gas fuel burners,
mechanical stoker attachment etc. is to be removed, and then the cleaning attended
to.
Any horizontal tube from which water can be drained should be cleaned of water. All
tubes cleaned internally by brushing or cleaned tool.
All boiler components must be cleaned thoroughly.
If the scale from the boiler components can not be removed, by mechanical cleaning,
chemical cleaning must be restored to, which must be attended to by experts.
Before entering a boiler, it must be ascertained that it is isolated from other boilers
under steaming condition.
All steam drum internals are to be removed for cleaning.
After the boiler is thoroughly cleaned and attended, the boiler must be offered for
inspection.
A powerful torche or if available, a portable lamp of 24 volts or less should be made
available for internal inspection.

Preparation for Hydraulic Test of a boiler:

Before starting a boiler which has been laid up due to repairs, or after statutory
inspection, it is tested hydraulically to 1.¼ to 1.½ times the working pressure. For
avoiding excessive heating and chilling of boiler drums, the temperature of water
used to fill the boiler should not be 10ºC (50ºF) above or below the temperature of
drums. While filling water, the superheater should be filled first and demineralized
water used. All sections when filling water must be thoroughly vented. All mountings

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subject to pressure shall be in place shut tight. The safety valve should be removed
and the openings blanked, or a clamp fitted to valve discs to secure them to their
seats. The safety valves adjustment should not be screwed down for the hydraulic
test.
The safety valves are to be restored to working condition after the hydraulic tests are
made and test them after the boiler is again placed in service. This action should
never be delayed because it is likely to be forgotten.
All doors should be jointed and tightened up. The boiler should be completely filled
with water at room temperature, care being taken to allow all air to escape, and if
possible a preliminary test not exceeding the working pressure of the boiler should be
taken before the Inspector’s visit to test the tightness of the joints.
When the boiler is hydraulically tested for the first time, it should be entirely cleared
of lagging or brickwork. At subsequent tests the lagging or brickwork or portions
thereof should be removed, if required, by the Inspector.

What is Engineers’ duty when he discovers any defect in boiler or boiler under his
charge?
Shut down the boiler without delay and immediately notify the employer and boiler
inspecting authority. Thereupon the management notifies the Chief Inspector of
Boilers of any such occurrences and requests a visit for inspection. No repairs of any
kind must be carried out unless authorised in writing by the Chief Inspector of Boilers.

What are the parts which require special attention of the boiler during the annual
inspection?
The shell, furnace end and tube plates, barrel, fire box, casing plates, drums and
their internals, headers, uptake, crowns and tubes must internally examined for
corrosion, bulging distortion, pitting, grooving, general wasting of plates, rivets,
stays, broken rivet heads, fractured stay bars, cracks, signs of leakages, sagging,
hogging and withdrawal of tubes where expanded. Inspection of braces for soundness
and proper tension, the internal feed pipe and anti-priming pipe should be carried out
to ensure that they are properly supported and not choked with sediment, and the
gauge glass cock passages to see that they are not choked. The man and mud hole
covers should be checked for good fit and the condition of their studs etc. examined.
The ligaments between tube holes in the heads of Fire tube boilers and in the shells
of water tube boilers should be examined for leakages.

Some important definitions as per Indian Boiler Act 1923.

“Boiler” means any closed vessel exceeding [22-75 litres] in capacity which is used
expressly for generating steam under pressure and includes any mounting or other
fitting attached to such vessel which is wholly or partly under pressure when steam is
shut off:

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Boiler O & M Engineers – Reference Material
“Accident” means an explosion of a boiler or steam-pipe or any damage to a boiler or
steam-pipe which is calculated to weaken the strength thereof so as to render it
liable to explode;
“Economiser” means any part of a feed-pipe that is wholly or partially exposed to the
action of flue gases for the purpose of recovery of waste heat;
“Owner” includes any person using a boiler as a agent of the owner thereof and any
person using a boiler which he has hired or obtained on loan from the owner thereof;
“Board” means the Central Boilers board constituted under section 27A
“Feed-pipe” means any pipe or connected fitting wholly or partly under pressure
through which feed water passes directly to a boiler and which does not form an
integral part thereof;
“Steam pipe” means any pipe through which steam passes from a boiler to a prime
mover or other user or both if –
(i) The pressure at which steam passes through such pipe exceeds 3.5 kilograms
per square centimeter above atmospheric pressure:
or
(ii) Such pipe exceeds 254 millimeters in internal diameter:
and
includes in either case any connected fitting of a steam pipe.

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