Examination and Inspection Program in ASME Pressure Vessel Construction
- Article Title:
Examination and Inspection Program in ASME Pressure Vessel
This article provides information about examination and inspection
requirement in pressure vessel construction. The article explains the
pressure vessel manufacture quality control and authorized inspector
ASME Code VIII-1 requires that an independent quality system is
established in-house by each manufacturer to ensure that the design,
materials and workmanship as specified are checked at each stage of
manufacture for compliance with requirements. The in-house quality
control exercise is called Examination.
Third party inspector is known as "Authorized Inspector [AI]",
who is suitably qualified and recognized as per ASME Section VIII Div.1
Clause UG-91. He is further required to carry out inspection at
Mandatory appendix 10 describes in brief the quality system required,
and highlights essential features. It should suit individual Company's
existing culture. A written description of the system in the form of a
Quality Manual, and should depict the process employed to manufacture a
Top Management should clearly define authority and responsibility of
persons performing quality related functions, and vest in them the
requisite organizational freedom, authority and independence to monitor
and verify the functioning of the system, to identify quality related
problems and to initiate, recommend and provide solutions.
The organization chart must describe the inter-relations between Top
Management and the departments, and the responsibility matrix within the
It is necessary the manufacture take care about document control. The
Current revisions of Drawings, Design Calculations and specifications
only should be used. Changes and revisions should be duly authorized and
diligently conveyed through appropriate channels.
Appropriate, Code approved material only should be used in construction.
Materials should be identifiable and relatable with material TCs, which
should be verified to comply with Code requirements. Handling and
storage should ensure trace ability of material.
Examination and Inspection Program
The requirements for examination and inspection program summarized in
manufacture and authorized inspector responsibilities as below:
· Obtaining Certificate of authorization from ASME BPV
Committee to fabricate the class of vessel being constructed.
· Preparation of fabrication drawings and design calculations
for the vessel
· Identification and traceability of materials used in
construction / fabrication of vessel.
· Partial Data Reports ( Form U2): Data Reports for parts for
pressure vessel parts, which are supplied by a sub-vendor, and which are
required to be examined and inspected, shall be obtained [in duplicate]
from the sub-vendor.
· The Authorized Inspector [AI] shall be given free access to
all areas of the works where relevant manufacturing work is being
performed. He shall be given access to the relevant documents.
· All materials shall be examined prior to fabrication to
make certain that;
a) They have the required minimum thickness / scantlings
b) The defects and imperfections, if any, are detectable/detected
and eliminated in the interest of the safety of the vessel.
c) Only Code permitted/approved materials are used.
d) The material identification and traceability are maintained.
e) Impact test properties, if required, are verified and recorded.
· Concurrence of Authorized Inspector prior to Repairs shall
be obtained. Defective material that cannot be satisfactorily repaired
shall be rejected. Acceptance of repairs and repaired items shall be
obtained from INSPECTOR.
· Formed shells and heads shall be examined to specified
shapes, permissible tolerances, using templates, gauges and instruments.
· Welding procedures and performances shall be qualified
prior to being employed in construction.
· All parts shall be examined prior to and at fitup stage, to
ensure that the surfaces at the joints are cleaned thoroughly, and
aligned within tolerance limits.
· Examination ( in-process ) to ensure that:-
a) Traceability of material identification,
b) Evidence of defects cropping up, and
c) Dimensional geometries are taken care of.
· Ensuring that Inspector has accepted the results of
non-destructive testing, and that all the NDT is satisfactorily
performed, recorded, and documents maintained and retained for
prescribed period of time.
· Performing prescribed pressure tests on the completed
pressure vessel - hydrostatic or pneumatic, under the witnessal of the
AI and Client's representative if required.
· Applying stamping/code stamp/nameplate on the vessel tested
to satisfaction of the Inspector.
· Preparation of Manufacturer's Data Report [MDR] (Format
U-1) and obtaining certification/endorsement thereof from the Authorized
Inspector. MDRs shall be retained for prescribed period of time.
Authorized Inspector Responsibility;
· Verification that manufacturer has fulfilled his
responsibilities as described above.
· Performing internal and external examination of the vessel.
· Visual inspection of the vessel to ensure that there are no
materials or dimensional defects.
· Witnessing hydrostatic or pneumatic tests on the Vessel.
· Verification that results of all the tests performed are
· Verifying that required marking for identification is
provided, and name plate attached.
· Signing Certificate of Inspection and MDR (Format U-1),
when the vessel is completed as per the Code.
Quality Control Plan
At the outset, a quality plan shall be prepared by Manufacturer
indicating fabrication stages of operations where specific examinations
and inspections are to be performed. Hold points for inspection shall be
marked by the Authorized Inspector.
A system for recording and correcting/eliminating non-conformities shall
be prepared, and after approval by the Authorized Inspector, documented
and implemented. Completed component and equipment shall fully comply
with Code requirements.
Welding shall comply with requirements of ASME Section IX, and the
application Code. The responsibilities and interfaces shall be clearly
Procedures for identifying appropriate NDT Techniques, in compliance
with Code requirements shall be established. Written practices for
conducting ND examinations shall have AI's approval and shall be
implemented as prescribed.
Quality System shall identify heat treatments applicable for materials,
vessel components and completed vessel. Review of heat treatment
methods, arrangements and furnace time temperature records, by AI shall
Measuring Instruments and Test equipment shall be identified, listed,
required accuracies established, and calibrated at predetermined
intervals with Masters whose accuracy is in turn calibrated/traceable to
National Standards. Records of calibration and validity shall be
displayed and be made available for scrutiny.
Typical Formats of Inspection Reports, Registers, Records related to
Quality measurements and observations, identification labels, tags and
stickers, should be CONTROLLED (i.e. format as prescribed, approved,
available for review and referred to in the manual).
Reference shall be made to Authorized Inspector as defined in UG-91.
Controlled Copy of Manual shall be made available to him. He shall have
access to all drawings, calculations, specifications, procedures,
process sheets, repair procedures, records, test results and any other
documents pertaining to inspection of the pressure vessel/s under his
The above discussion will help pressure vessel manufactures to develop
their own Quality System in line with Appendix 10 of ASME Section VIII
Div. 1 which is a mandatory requirement before applying for ASME
Babak Rasooli is Industrial Inspection Instructor and consultant with
more than 15 years experience in oil, gas and petrochemical industries.
He has written lots of articles about vendor inspection, commodity
inspection and preshipment inspection.Visit
for more information on quality control system in pressure vessel and
other industrial equipment.
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