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Examination and Inspection Program in ASME Pressure Vessel Construction

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  • babak r
    Article Title: Examination and Inspection Program in ASME Pressure Vessel Article Description: This article provides information about examination and
    Message 1 of 1 , Aug 6, 2012
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      Article Title:

      Examination and Inspection Program in ASME Pressure Vessel



      Article Description:

      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
      responsibilities.

      Article Body:

      Introduction

      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
      stipulated stages.

      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
      Code item.

      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
      organization.

      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:

      Manufacturer's Responsibility;

      · 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
      acceptable.

      · 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
      defined here.

      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
      be provided.

      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
      purview.

      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
      certificate.

      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
      http://www.inspection-for-industry.com/industrial-quality-control.html
      <http://www.inspection-for-industry.com/industrial-quality-control.html>
      for more information on quality control system in pressure vessel and
      other industrial equipment.





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