API STD 599:2007 pdf download.Metal Plug Valves- -Flanged, Threaded and Welding Ends.
Covers shall have nut bearing surfaces for bolting that are parallel to the cover face within 1 degree. When spot- facing or back-facing of flange covers Is required, it shall be In accordance with the requirements of ASME 816.5 for end flanges.
4.4 Stem and Plug
4.4.1 Stem retention and stem strength shal meet the requirements of Paragraph 6.5.1.1 and 6.5.1.2 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 lies 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 applied to handle or gear operator produces a torque equal to the greater of 20 N-rn (15 tI-Ib) or two times the manufacturer’s maximum published torque at maximum differential pressure at 21°C (70°F) on dry air seivice. 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 e4astomeric or plastic sleeves, liners, seals, gaskets, or seats are not coated with an etastomer 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 finish 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 microincties (0.80 micrometers) in accordance with ASME 846.1.
4.5 Glands
Adjustable glands may be a threaded type, a bolted one-piece type. or a bolted two-piece, self-aligning 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 Bi 82.2.
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 1 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 81.12.
4.6.3 Gland bolting shall pass through holes in the gland. The use of open slots is not permitted in the cover flange. cover, adjuster, or gland.
API STD 599:2007 pdf download
