There are few basic information required to carry out the erection / construction of
pressure parts of boiler. These items are described briefly below for ready reference.
The welding of all pressure parts and high pressure piping shall be in accordance
with the following requirements:
Qualification of Weld Procedures
All the welding procedures adopted shall be qualified in accordance with the latest
applicable requirements of Section IX of ASME code before the work is begun.
Certified welding procedures for welding of pressure parts and piping's should
contain the type of material, material thickness, the joint details, the pre-heat
temperature maintained, the post weld heat treatment given and the welding current
and the voltage used during qualifications of welding procedures.
Welder's Qualification
Only welders, qualified in accordance with the latest applicable requirements of
the Indian Boiler Regulations, shall be permitted to perform any welding work
on the pressure parts. In addition to such statutory qualification requirements,
the welders shall also perform a satisfactory pre-production qualification test to
be conducted at site in consultation with site welding engineer . The services of
an independent testing laboratory can be retained to perform welder qualification
tests for welders.
All the welders carrying out welding at site, shall carry an identification badge,
which shall indicate the category and the grade of welding for which they have
been tested and authorised to carry out welding. All such badges shall be presented
on demand to the inspection authority.
All records of the welding procedures, the welder's qualification tests and
the welders' performance details for the work performed shall be maintained .
The names of all the welders who made each weld on the boiler pressure parts and
piping within the jurisdiction of the Indian Boiler Regulations shall be maintained .
The certified copies of any or all the above documents shall be submitted to
authority on demand. Marking of welded joints to be done as per norms.
HEAT TREATMENT
Pre-heating, post-heating and post - weld stress relief operations of all welds, shall be
performed in accordance with the requirements of applicable code. Local post weld
stress relieving heat - treatments shall be adopted only in cases where it is normally
impracticable to subject the entire assembly as such for stress relieving operations.
Heating may be by means of electric induction coils or electric resistance coils.
Oxyacetylene flame heating or exothermic chemical heating methods will not be
permitted. Complete recording of the temperatures through out the stress relieving
cycle of the material and the weld subjected to heat treatment shall be made by means
of a potentiometric recorder. Recorders other than those of potentiometric type shall
not be used for such temperature recording during stress relieving operations.
After setting up the weld joint for heat treatment operation, signatures shall be obtained
on the strips chart of the recorder prior to starting of heat treatment cycle. The right
hand corner of the strip chart at the starting point of the heat treatment cycle shall
contain details like the weld number, material, diameter and thickness, method of
heating adopted, prescribed ranges of heat treatment temperatures, date of heat treatment,
reference to item number of the Field welding Schedule.
FIELD WELDING SCHEDULE
Field welding schedule should contain following information:
a) Drawing No (s)
b) Location of the weld
c) Size of the weld (outside diameter and thickness)
d) Type of joints
e) Material specifications
f) Size of fillet on backing ring, when the type of joint is with backing ring
g) Electrode/ filler metal specifications
h) Number of welds per unit
i) Quantity of filler metal per weld
j) Indication of required Non-destructive Examination (NDE) for each weld
k) Pre-heat temperatures for welding
l) Process of welding
m) Post-welding heat treatment temperature ranges, duration, entitled 'Qualification of Weld Procedures' .
Continued to part-III
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pressure parts of boiler. These items are described briefly below for ready reference.
The welding of all pressure parts and high pressure piping shall be in accordance
with the following requirements:
Qualification of Weld Procedures
All the welding procedures adopted shall be qualified in accordance with the latest
applicable requirements of Section IX of ASME code before the work is begun.
Certified welding procedures for welding of pressure parts and piping's should
contain the type of material, material thickness, the joint details, the pre-heat
temperature maintained, the post weld heat treatment given and the welding current
and the voltage used during qualifications of welding procedures.
Welder's Qualification
Only welders, qualified in accordance with the latest applicable requirements of
the Indian Boiler Regulations, shall be permitted to perform any welding work
on the pressure parts. In addition to such statutory qualification requirements,
the welders shall also perform a satisfactory pre-production qualification test to
be conducted at site in consultation with site welding engineer . The services of
an independent testing laboratory can be retained to perform welder qualification
tests for welders.
All the welders carrying out welding at site, shall carry an identification badge,
which shall indicate the category and the grade of welding for which they have
been tested and authorised to carry out welding. All such badges shall be presented
on demand to the inspection authority.
All records of the welding procedures, the welder's qualification tests and
the welders' performance details for the work performed shall be maintained .
The names of all the welders who made each weld on the boiler pressure parts and
piping within the jurisdiction of the Indian Boiler Regulations shall be maintained .
The certified copies of any or all the above documents shall be submitted to
authority on demand. Marking of welded joints to be done as per norms.
HEAT TREATMENT
Pre-heating, post-heating and post - weld stress relief operations of all welds, shall be
performed in accordance with the requirements of applicable code. Local post weld
stress relieving heat - treatments shall be adopted only in cases where it is normally
impracticable to subject the entire assembly as such for stress relieving operations.
Heating may be by means of electric induction coils or electric resistance coils.
Oxyacetylene flame heating or exothermic chemical heating methods will not be
permitted. Complete recording of the temperatures through out the stress relieving
cycle of the material and the weld subjected to heat treatment shall be made by means
of a potentiometric recorder. Recorders other than those of potentiometric type shall
not be used for such temperature recording during stress relieving operations.
After setting up the weld joint for heat treatment operation, signatures shall be obtained
on the strips chart of the recorder prior to starting of heat treatment cycle. The right
hand corner of the strip chart at the starting point of the heat treatment cycle shall
contain details like the weld number, material, diameter and thickness, method of
heating adopted, prescribed ranges of heat treatment temperatures, date of heat treatment,
reference to item number of the Field welding Schedule.
FIELD WELDING SCHEDULE
Field welding schedule should contain following information:
a) Drawing No (s)
b) Location of the weld
c) Size of the weld (outside diameter and thickness)
d) Type of joints
e) Material specifications
f) Size of fillet on backing ring, when the type of joint is with backing ring
g) Electrode/ filler metal specifications
h) Number of welds per unit
i) Quantity of filler metal per weld
j) Indication of required Non-destructive Examination (NDE) for each weld
k) Pre-heat temperatures for welding
l) Process of welding
m) Post-welding heat treatment temperature ranges, duration, entitled 'Qualification of Weld Procedures' .
Continued to part-III
P.S If you are looking to earn few legitimate extra money from the comfort of your home then please click on the link given below
LINK 1 - PLEASE CLICK HERE
LINK 2 - PLEASE CLICK HERE
Nice Post. So informative. Keep sharing!
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Great Blog! Post Weld Heat Treatment.
ReplyDelete