API RP 621:2010 pdf download

API RP 621:2010 pdf download.Reconditioning of Metallic Gate,Globe, and Check Valves.
5.4 Disassembly and Cleaning of Valves
5.4.1 Valves to be reconditioned shall be completely disassembled.
5.4.2 Old packing, gaskets, and bonnet bolting shall be removed and disposed of in accordance with owner’s instructions and/or applicable regulations.
5.4.3 Tags from previous reconditioning shall be removed and the tag, or data from the tag, shall be placed in the reconditioned valve record document. OEM tags, if still attached to the valve, shall be removed.
5.4.4 Immediately after disassembly, the valve’s newly assigned identification number shall be metal stamped onto the valve’s closure element, stem/shaft, seat rings if removed, and any other major part. Stamped markings shall remain on the individual valve components after the reconditioning process is completed and the valve is returned to the Owner.
a) Stamping shall be on non-functional surfaces and shall be made with low stress stamps.
b) If stamping is not practical, parts shall be tagged or electro-etched. However, all stems and closure elements for valves NPS 2 (DN 50) and larger shall be marked by stamping.
5.4.5 Unless a specific cleaning method is specified by the Owner, valve parts shall be thoroughly cleaned by any usual method, such as steam, chemical, sand/bead, or steel shot blasting. Finished surfaces that may be damaged during the cleaning process shall be protected.
5.4.6 Cleaning process shall remove all or nearly all paint, grease, wst, and product from both internal and external surfaces.
6 Repair of Valve Parts
6.1 General
6.1.1 Welding
6.1.1.1 Welding procedures and welders shall be qualified in accordance with Section IX of the ASME Boiler and Pressure Vessel Code.
6.1.1.2 Welding procedures shall be submitted to the Owner for approval prior to the start of welding.
6.1.1.3 Weld metal buildup and weld metal repairs, including any required post weld heat treatment, shall be performed in accordance with the approved procedures.
6.1.2 Nondestructive Examination (NDE)
6.1.2.1 Welds, other than tack welds, shall be examined by the liquid penetrant method or by the nondestructive examination (NDE) method specified by the Owner.
6.1.2.2 NDE of parts and/or weld repairs shall be done in accordance with owner-approved NDE procedures and acceptance criteria.
6.1.2.3 SNT-TC-1A Level II technicians certified for the procedures per ASME Section V shall evaluate NDE results.
6.1.3 Replacement Parts and Material
6.1.3.1 Sources of replacement parts shall be one or more of the following in preferential order:
a) Parts purchased from the OEM or other OEM approved source;
b) Parts salvaged from scrapped valves from the same valve manufacturer and with matching identification;
c) Parts manufactured in the reconditioning facility, when approved by the Owner.
6.1.3.2 Material used to manufacture replacement parts in the reconditioning facility shall be as specified by the owner or the following in preferential order.
a) If the owner does not specify material, the material used (including heat treatment if applicable) shall be the material used by the original valve manufacturer and shall comply with the requirements of the referenced standard.
b) Changes in material group, such as 13CR to austenitic stainless steel, require approval of the Owner.
c) Verification of the specific material used and its source shall be part of the required documentation.
6.1.3.3 As a minimum, the following components shall be replaced:
a) Soft seats;
b) Bonnet and cover bolting;
c) Packing;
d) Gaskets;
e) Grease fittings.
6.2 Inspection of Valve Parts
6.2.1 General
6.2.1.1 Valve parts shall be inspected to determine their acceptability for re-use and/or extent of required repair.
6.2.1.2 Criteria for acceptability and extent of repair shall be the component’s ability to meet the Owner’s expectation for continued service in his facility.
6.2.2 Threaded Parts
6.2.2.1 Threaded parts shall be visually inspected for gross defects, such as missing or incomplete threads, defective thread profile, torn or ruptured surfaces, and cracks.
6.2.2.2 Surface texture of threaded parts shall be evaluated by visual or tactile comparison with texture specimens or surface measurement equipment.
6.2.2.3 Visual inspection shall be made without magnification. Thread acceptability criteria shall be specified by the Owner in accordance with ASME B1.3.