Regulation 391A – Ageing of boilers

(a) Shell Type Boilers :-

(i) In order to take the ageing effect on boilers, the working pressure of the parts of them as calculated from the formulae in these regulations shall be reduced as per table given below :-

Age of Boiler exceeding ( in years)

25 35 45 50 60 70 80 90 100

Maximum permitted working pressure percent.

95 90 85 80 70 60 50 40 30

(ii) For those boilers the plate of which have already been cut and tested under regulation 7 and this boilers shall be given a further lease of life of 50 years from the date of test of boilers. The working pressure that shall be allowed after the testing shall be reduced as per the table given below:-

Period after date of test(in years)

10 20 30 40 50

Maximum working pressure allowed(percentage)

90 80 70 50 30

(b) Water Tube Boilers:-

(i) The boilers which are operating at a temperature of 400oC and above including utility or industrial boilers and all boiler parts operating the in the creep range of the boiler shall be non-destructively tested as per the table 1 given below after they are in operation for 1,00,000 hours for assessment of the remanent life of the parts;

(ii) The parts of a boiler when it completes a life of twenty five years are to be tested as per table 2 for assessment of the remanent life of such parts. If results are acceptable as per the standards laid down by the Central Boilers Board, a certificate shall be issued by the Chief Inspector of Boilers for extending the life of the boiler for a further

period of ten years or such less period as recommended by the Remanent Life Assessment Organization. This assessment of remanent life shall be carried out thereafter every five years by the organizations working in the field of boilers and remanent life and extension thereof after such organization is approved by the Central Boilers Board. Such organization shall work in close coordination with the office of the Technical Adviser (Boilers) in the field of remanent life assessment and extension. The working pressure of such boilers may be reduced on the recommendations of such approved organization.

T A B L E 1

Component

Visual Ultrasonic

testing

MagneticParticleinspection

Liquid/dye penetrantinspection

Replication samp

ling

DepositAnalysis

OutsideDiametreandthickness

fibreopticinspection

Hardness

Others

(1) (2) (3) (4) (5) (6) (7) (8) (9) (10) (11) (12)Drum

(Steam)Yes Yes No Yes Yes No Yes No No Yes

Waterdrum

Yes Yes No Yes Yes No Yes Yes No Yes

LowTemper-

atureHeader

Yes No No Yes No No No Yes Yes Yes

Attemp-eratorheader

Yes Yes No Yes Yes No No Yes Yes Yes SwellMeasure-

mentHigh

temper-ature

Econo-misertubes

Yes No No No No Yes No Yes No No

LowTemper-

atureEcono-misertubes

Yes No No No No Yes No Yes No No

Convec-tion

Super-heater

Yes No No No No Yes Yes Yes No Yes

CoilsPrimarySuper-heaterCoils

Yes No No No No Yes No Yes No Yes Non-destructive

Oxidethicknessinspection

PrefinalSuper-heaterCoils

Yes No No No No Yes No Yes No Yes

FinalSuper-heaterCoils

Yes No No No No Yes No Yes No Yes

ReheaterCoils

Yes No No No No Yes No Yes No Yes

HighTemper-

atureheaders

Yes Yes No Yes Yes No No Yes Yes Yes

FinalSuper-heaterheader

Yes Yes No Yes Yes No No Yes Yes Yes SwellMeasure-

ment

Reheaterheader

Yes Yes No Yes Yes No No Yes Yes Yes SwellMeasure-

mentMain steampiping

Yes No No NO Yes No No Yes No Yes

Platensuper-heaterheader

Yes Yes No Yes Yes No No Yes Yes Yes

Primarysuper-heaterheader

Yes Yes No Yes Yes No No Yes Yes Yes

Econo-miserheader

Yes No No Yes No No No Yes No No

Auxi-liaries

Yes No No No No No No Yes No No

BoilerBankTubes

Yes No No No No No No Yes No No

Waterwall

Yes No No No No No No Yes No No

Furnacewaterwalls

Yes No No No No No No Yes No No

T A B L E 2

Compo-nent

Visual Ultra-sonic

testing

Mag-netic

ParticleInspection

Liquid/Dye

Pene-trant

Inspection

Repli-cation

Samp-ing

Depo-sit

Analy-sis

OutsideDiameter

andthickness

Fibre-opticInsp-ection

Hardness

Others

Drum(steam)

Yes No No Yes No No No Yes No No

Waterdrum

Yes No No Yes No No No Yes No No

Econo-misertubes

Yes No No No No Yes No Yes No No

Convec-tion

Superheatercoils

Yes No No No No Yes No Yes No No

PrimarySuperheatercoils

Yes No No No No Yes No Yes No No

FinalSuperheatercoils

Yes No No No No Yes No Yes No No

HighTemp-ature

headers

Yes No No Yes Yes No No Yes Yes No

FinalSuperheater

Yes No No Yes Yes No No Yes Yes No

headersEcono-miserheader

Yes No No No No No No Yes No No

Auxi-liaries

Yes No No no No No No No Yes No

Boilerbanktubes

Yes No No No No No No Yes No No

Waterwalls

Yes No No No No Yes No Yes No No

MainsteamPiping

Yes No No No No Yes No Yes No No

No.20(37)/99-BoilersGovernment of India

Ministry of Commerce & IndustryDepartment of Industrial Development

Sub: Amendment of Reg.391A of Indian Boiler Regulations,1950 - reg.

Dear Sir,

I am directed to invite your attention to item 4 of part II (IV) of the record note of the 68th meeting of Central Boilers Board and to say that the board considered the recommendations of the Sub-Committee and decided that in respect of boilers working at a p;ressure less than 50 kg/cm2, remanent life assessment is not mandatory. The Board further decided to amend the relevant regulation in this regard. However, pending such amendment, remanent life assessment of boilers of such boilers may not be insisted upon. For boilers working at a pressure 50 kg/cm2 and above the Board decided that drums and headers of such boilers be inspected by ultrasonic testing, magnetic particle testing and dye penetrant.

Yours faithfully,Sd/M.L.AhuzaAssistant Secretary, CBB