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Reg. 391 A
Aging of boilers
| a) |
Shell Type Boilers:-
| (i) |
In order to take the
aging effect on boilers, the working pressure of
the parts of them as calculated from the formulae
in these regulations shall be reduced as per the
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 |
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| (ii) |
For those boilers the
plates of which have already been cut and tested
shall be given a further lease of life of fifty
years from the date of the test of the 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 |
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| b) |
Water Tube Boilers: -
| (i) |
The boilers which are
operating at a temperature of 400°C and above
including utility or industrial boilers and all
boiler parts operating 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 remnant
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
remnant 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 Remnant Life Assessment
Organisation. This assessment of remnant life shall
be carried out thereafter every five years by the
organisations working in the field of boilers and remnant
life and extension thereof after such organisation
is approved by the Central Boilers Board. Such organisation
shall work in close coordination with the office
of the Chief Inspector of Boilers in the field
of remnant life assessment and extension. The working
pressure of such boilers may be reduced on the recommendations
of such approved organisation.
Notwithstanding
anything contained in this regulation, for boilers
working at a pressure less than 50 kg/cm2,
such elaborate remnant life assessment is not
mandatory. However,
in such cases, drums and headers of such boilers
shall be inspected by Ultrasonic testing, Magnetic
particle testing and Dye penetrant test.
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