Pressure Vessel Safety

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Pressure Vessel Safety

• Paul Brindza
• March 27, 2007

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Pressure Vessels

• Pressure Greater than 15 PSI differential
• Diameter greater than 6 inches
• Metallic (welded, bolted , riveted)
• ASME section VIII Division 1 or 2 for unfired
  vessels applies (PVC)
• Other sections of ASME PVC apply to materials,
  welds, brazing, inspections
• Safety factor of 3.5 Div 1
• Test pressure of 125 Div 1

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Pressure Piping

• Pressure greater than 15 PSI differential
• Diameter greater than ¼ inch
• ANSI B31 Chemical Plant and Refinery Pressure
  Piping Code applies ( PPC)

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Pressure Safety at JLAB before 10CFR851 Feb. 9,
2006

• All JLAB Super Conducting Magnets that were
  procured thru Design-Build Contracts had the
  following language in the specification
• This SC magnet shall be designed , fabricated and
  tested to the intent of ASME PVC Section VIII for
  unfired vessels,
• but No Code Stamp was required.
• JLAB EHS Manual required use of ASME PVC for
  design guidance in a similar manner for JLAB
  projects.

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After 10CFR851

• This DOE order requires that all its contractors
  (JLAB) to be fully compliant with ASME PVC ANSI
  B31 PPC.
• This requires that legacy systems shall be
  documented to demonstrate compliance or that the
  contractor shall get a variance from a Committee
  of experts (JLAB) established to review future
  and past compliance.

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Applicability to 12 GeV Projects

• SC Magnets have two pressure systems Helium
  Nitrogen where ASME PVC will now apply and
  magnets must in the future be procured with a PV
  Code Stamp (U-stamp) and be documented
  accordingly.
• SC magnet vacuum systems, other vacuum systems
  and Cerenkov Counters can be excluded if they
  have relief devices that prevent positive
  pressurization over 15 PSI.
• Cryogenic targets must get a JLAB exception from
  the Pressure Safety Committee.

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IMPACTS

• Code compliance requires extensive record keeping
  involving design documents, calculations,
  professional peer reviews, and a host of
  fabrication documents and test and inspection
  results.
• Materials certifications, part traceability, weld
  design, weld welder certifications must be
  preserved.
• Inspectors must be Code certified.
• JLAB welding welders have to be code certified
  so JLAB can build or repair to ASME Sec. VIII or
  ANSI B31

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Conclusions

• Compliance is not mission impossible.
• JLAB has always followed the intent of the
  CODEs so compliance by documentation or
  professional review is possible for Legacy
  systems.
• It will cost more for JLAB to perform its work
  due to higher contract costs and staff costs will
  increase due to requirements for certified staff
  and inspectors and record keeping.