2. UG-77 Material Identification
• On completed vessel, original identification markings,
or transferred markings or coded markings (traceable
to original) shall be visible on each vessel part
• Any marking method which is acceptable to inspector
• When service conditions prohibit die-stamping, any
method with positive identification may be adopted
• When original markings are unavoidably cut, coded
markings may be adopted which shall be described in
QC system
3. UG-78 Repair of defects in materials
• Method & extent of repair shall be acceptable to
inspector
• Defective material that cannot be satisfactorily
repaired shall be rejected
4. UG-84 Charpy Impact Tests
• Production Test Coupons
– Test plate shall be from one of heats of vessel
– For category A joint, test plate shall, where
practicable, be welded as an extension to end of
production joint
– For category B joint (welded using different welding
procedure than used on category A joints, test plate
shall be welded under production welding
conditions used for vessel, using same type of
equipment and at same location and using same
procedures as used for joint and it shall be welded
concurrently with production welds or as closed to
start of production welding as practicable
5. UG-84 Charpy Impact Tests
• Production Test Coupon
– One test plate for each welding procedure for
categories A & B
– For automatic or semi automatic welding, one test
plate in each position
– For manual welding, vertical upward welded test
plate qualify for all position.
– If PTC fails to meet the impact requirements, welds
represented shall be unacceptable. Reheat treatment
and retesting or retesting only are permitted.
6. UW-3 Weld joint category
• Defines the location of a joint in a vessel
• Established for use in specifying joint type and degree
of inspection
• Based on service, material and thickness, special
requirements are specified in code
– Category A
– Category B
– Category C
– Category D
8. UW-11 Radiographic & Ultrasonic Examination
• Full radiography
– All butt welds in shell and heads of lethal service
vessels
– All butt welds with nominal thickness of weld
exceeds 38 mm or thickness specified elsewhere in
code. Category B & C butt welds in nozzles that
neither exceeds 10” size nor 29 mm wall thickness
do not require radiography
9. UW-11 Radiographic & Ultrasonic Examination
• Spot Radiography
– Butt welds of type 1 or 2 of table UW-12 which are
not required to be fully radiographed
– If spot radiography is specified for the entire vessel,
RT is not required for category B & C welds in
nozzles or communicating chamber that neither
exceeds NPS 10 nor 29 mm wall thickness
• No Radiography
– No radiography is required when the vessel or vessel
part is designed for external pressure only or when
the joint design complies with UW-12(C)
10. UW-26 General
• All welding shall be performed in accordance with
Manufacturer’s WPS in accordance with the
requirements of Sec IX
• All welders shall be qualified by Manufacturer in
accordance with the requirements of Sec IX
• Assign welder identification symbol
11. UW-32 Cleaning of surfaces to be welded
• Surfaces shall be clean and free of scale, rust, oil,
grease, slag, detrimental oxides and other deleterious
foreign material
• When metal is to be deposited over a previously welded
surface, all slag shall be removed by a roughing tool,
chisel, chipping hammer or other suitable means
12. UW-33 Alignment tolerances
• Alignment of sections at edges shall be such that
maximum offset is not greater than limit given in Table
UW-33
• Allowable offset shall be faired at a 3:1 taper over
width of finished weld, or if necessary, by adding
additional weld metal
14. UW-37 Miscellaneous Welding Requirements
• Welder & welding operator identification
– Stamp identifying number, letter or symbol on or
adjacent to and at intervals of not more than 1 m
along the welds in steel plates >= 6 mm and for non
ferrous plates >= 13 mm in thickness
– Stencil or other marking in welds in steel plates < 6
mm and for non ferrous plates < 13 mm in
thickness
– Record of welders / WOs employed on each joints
shall be kept
– For multiple welds, tube to tube sheet welds, QA
system shall have a procedure to identify welders or
welding operators
15. • Imperfections are unacceptable under following
condition
– Any crack or incomplete fusion or penetration
– Any elongated indication which has length greater
than
• 6 mm for t upto 19 mm
• 1/3t for t from 19 mm to 57 mm
• 19 mm for t over 57 mm
UW-51 Radiographic Examination of Welded Joints
16. UW-52 Spot Examination of Welded Joints
• One spot shall be examined for each 15 m increment
• Sufficient number of spot radiographs shall be taken to
examine welding of each welder or welding operator
• Location of spot shall be chosen by the Inspector
• Radiographs required at specific locations to satisfy
rules of other paragraphs shall not be used to satisfy
the requirements of spot radiography
• Minimum length of spot shall be 6 inch
17. UW-52 Spot Examination of Welded Joints
• Any crack or lack of fusion/penetration is unacceptable
• Any slag inclusions or cavities
– with length more than 2/3t shall be unacceptable
– If several indications within above limitations are in
line, weld is acceptable if sum of the longest
dimensions of all such indication is not more than t
in length of 6t and if longest indications considered
are separated by at least 3L where L is length of
longest indication
– Max. length of longest indication shall be 19 mm
– Less than 6 mm shall be acceptable
18. UCS-57 Radiographic Examination
• In addition to UW-11, RT is required for butt welds
which exceed thickness limit specified in Table UCS-57
19. App 6 - MPE & App 8 - LPE
• Acceptance standard
– All surfaces to be examined shall be free of
• Relevant linear indications
• Relevant rounded indications greater than 5 mm
• Four or more relevant rounded indication in a
line separated by 1.5 mm or less, edge to edge
20. Appendix 12 Ultrasonic Examination of welds
• Indications characterized as cracks, lack of fusion or
incomplete penetration are unacceptable regardless of
length
• Other imperfections are unacceptable if indications
exceed reference level amplitude and have lengths
which exceed
– 6 mm for t upto 19 mm
– 1/3t for t from 19 mm to 57 mm
– 19 mm for t over 57 mm
