API STD 599:2007 pdf download

API STD 599:2007 pdf download.Metal Plug Valves-Flanged,Threaded and Welding Ends.
4.3 Cover
Covers shall have nut bearing surfaces for bolting that are parallel to the cover face within 1 degree. When spot- facing 01 back-facing of flange covers is required, it shall be in accordance with the requiements of ASME B16.5 for end flanges.
4.4 Stem and Plug
4.4.1 Stem retention and stem strength shall meet the requirements of Paragraph 6.51.1 and 6.5.12 of ASME B16.34. The design shall not rely on actuation components (e.g. gear operators, actuators, levers, etc.) to prevent ejection.
4.4.2 Stem-to-plug connection and all parts of the stem within the pressure boundary shall under torsional load exceed the strength of the stem that bee outside the pressure boundary by more than 10 %. This shall be verified by destructive testing or calculation methods that have been verified by destructive testing on items of the same geometric configuration.
4.4.3 The stem and connection between stem and plug shall be designed to resist permanent deformation or failure of any part when a force appliod to handle or gear operator produces a torque equal to the greater of 20 N-rn (15 ft-tb) or two times the manufacturer’s maximum published torque at maximum differential pressure at 21 C (70F) on dry air service. This shall be verified by destructive testing or calculation methods that have been verified by destructive testing on items of the same geometric configuration.
4.4.4 If the surfaces of plugs that rotate against elastomeric or plastic sleeves, liners, seals, gaskets, or seats are not coated with an elastomer or plastic, these surfaces of plugs shall have a surface finish no rougher than Ra of 16 microinches (0.40 micrometers) in accordance with ASME B46.1. Lubricated plug valves shall have a surface flrwsh between the seat and plug that will insure maximum retention of lubricant as determined by the manufacturer.
4.4.5 Stem surface area in contact with the stem seal or packing shall be no rougher than Ra of 32 microinches (0.80 micrometers) in accordance with ASME B46. 1.
4.5 Glands
Adjustable glands may be a threaded type, a bolted one-piece type, cia bolted two-piece, self-alignrng type.
4.6 Bolting
4.6.1 Covers shall be bolted with studs, stud bolts, or cap screws. Studs and stud bolts shall be equipped with heavy, semifinished hexagon nuts that conform to ASME B 18.2.2.
4.6.2 Bolting shall be threaded in accordance with ASME B1.1. Bolting 1 in. or smaller shall have coarse (UNC) threads; bolting larger than I in. shall be of the 8-thread series (8 UN). Bolt threads shall be Class 2A. and nut threads shall be Class 2B. When wrench-fit studs are furnished, the wrench-fit end of these studs and the threaded hole shall have threads in accordance with a Class 5 interference fit, as specified in ASME BI .12.
4.6.3 Gland bolting shall pass through holes in the gland. The use of open siots is not permitted en the cover flange. cover, adjuster, or gland.
5.1 General
When service or environmental conditions, such as low temperatures or a corrosive environment, make spedal considerations necessary in choosing valve materials, the purchaser shall indicate this on the purchase order, and the materials shaM be as agreed upon by the purchaser and the manufacturer.
5.2 Shell
5.2.1 The shell, which comprises the body and the cover, shall be of a material listed In ASME B 16.34 or ductile iron listed in ASME B16.42. For ASME 816.34 listed matenals, the body and the cover do not have to be to idenhcal matenal specifications; however, the body and the cover shall be of materials of the same materials group.
5.2.2 A metalIoaphic examination may riot be substituted for the tensile test required by ASTM A 395.
5.3 Body-to-Cover Seals, Diaphragms, or Gaskets
When body-locover seals or metallic or nonmetallic diaphragms or gaskets are used, they shall be suitable for the service conditions and the valves pressure-temperature ratings. Where necessary, compression of the seals, diaphragms, or gaskets shall be controlled by a compression ring or by the body-to-cover design. The corrosion resistance of any metal in contact with the service fluid shall at least equal that of the body. The seal or gasket may be made of a material listed in Annex C, Table Cl. of ASME 816.5, or the seal or gasket may be made of a hydrocarbon- resistant plastic or elastorrier.
5.4 Stem and Plug
5.4.1 Plugs shall be made of one of the materials specified in ASME B16 34 or ductile iron specified in ASME B 16.42. Other materials may be used if they are specified in the purchase order The corrosion resistance of the plug shall be at least equal to that of the body. The plug surfaces shall have bearing properties that will resist galling. Steel plugs may be hard surfaced to provide the desired resistance to abrasion and galling. Other materials may be used if they are specified ii the purchase order. When ductife iron plugs are hard surfaced, hard surfacing shall not be applied by welding or brazing.