ASME PVHO-2:2019 pdf free download – Safety Standard for Pressure Vessels for Human Occupancy: In-Service Guidelines
The PVHO and PVHO systems user shall provide the designer with information regarding the service condi- tions that the PVHO and PVHO systems may encounter during their service life. The user shall protect the PVHO and its systems from hazards, and ensure they are used within their design limitations. It is the user, and not the designer or fabricator, who is responsible for determining the safe service life in accordance with the technical criteria and guidelines herein. The user is responsible for retaining all documentation for each PVHO and its associated systems, and shall establish a program of periodic inspection to determine the need for repair or replacement of any part, in accordance with the requirements listed in this Standard. For window repair and replacement requirements, refer to Section 2, Viewports.
The operationofeach PVHO is typicallygovernedunder specific rules of the jurisdiction in which it is operated. (Examples include, but are not necessarily limited to, the state, the U.S. Food and Drug Administration, and the U.S. Coast Guard.) This Safety Standard is intended to complement the jurisdictional requirements (i.e., to provide guidance to both users and jurisdictional autho- rities in regard to in-service requirements for the PVHO, acrylic windows, and PVHO systems). The responsibility for compliance with jurisdictional in-service require- ments, which may become invoked as a result ofthe tech- nical criteria and guidelines as set forth herein, lies with the user.
The owner shall be responsible for performing period- icalpressuretestingofthePVHOpressureboundary,pres- surized systems, and PVHO operational systems. Test pressures shall be at maximum operating pressure and not exceed the maximum allowable working pressure of the components/systems being tested. These tests shallbeperformedanddocumentedataperiodicityestab- lished by the user, manufacturer, and/or applicable juris- diction. Pressuretestingshallbeperformedonanyvalve,fitting, and/or piping/tubing that penetrate the PVHO pressure boundary following reassembly or replacement. The test boundary shall include the first stop valve both upstream and downstream of the reassembled or replaced compo- nent. Pressure testing after pressure vessel or piping weld repairs shall be a hydrostatic or pneumatic test and shall follow the applicable pressure vessel or system component code or standard. Newpressure boundarycomponents (i.e., valve, piping, and windows) shall be hydrostatically or pneumatically tested in accordance with the applicable pressure vessel or system component code or standard.
When evidence ofa flawis detected ora modification of a PVHO pressure boundary is planned, the owner shall be responsible for ensuring that the PVHO is evaluated and repaired, replaced, or modified in accordance with the re- quirements ofthis Standard, applicable codes, and appro- priate jurisdictional authorities.
(a) In-service flaw evaluation techniques, such as non- destructive examination, shall be applied to assess the potential impact to the structural integrity against the PVHO’s original design specification and code. Alterna- tively, the PVHO can be evaluated to the current code provided it is applied to the entire PVHO.
(1) PVHOs designed, fabricated, and tested to ASME Boiler and Pressure Vessel Code (BPVC), Section VIII, or certified to ASME PVHO-1 alternative design rules, that show signs of flaws or damage may be evaluated using API 579-1/ASME FFS-1.
(2) PVHOs thatare designed and fabricated to ASME PVHO-1 Code Cases shall be evaluated and repaired in accordance with requirements stated in the case.
(b) Pressure boundary repairs shall include a plan and repair and test procedures consistent with the applicable code.Repairs thatdo notbringthePVHO totheoriginal“as designed” condition are considered a modification.
(1) ForPVHOsstampedperASME BPVC, SectionVIII, the National Board Inspection Code (ANSI/NBBI NB-23) provides applicable weld repair and modification proce- dures.
(2) All other repairs shall be certified by a qualified Professional Engineer or Authorized Inspector to be in compliance with this Standard and applicable code(s). (c) Pressure boundary modifications shall be performed in accordance with the most recent code regardless of the original year of fabrication. A Profes- sional Engineer shall be responsible for the modification design and compliance with applicable code require- ments.