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 I degree. When spot- facing or back-facing of flange covers is required, it shall be in accordance with the requirements of ASME B 16.5 for end flanges.
4.4 Stem and Plug
4.4.1 Stem retention and stem strength shall 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 Stern-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 ft-lb) or two times the manufacturer’s maximum published torque at maximum differential pressure at 21°C (70°F) 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 elastomenc 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 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 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, 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 B18.2.2.
4.6.2 Bolting shall be threaded in accordance with ASME Bi .1. Bolting 1 in. or smaller shall have coarse (U NC) 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 Bi .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.
4.6.4 Packing gland bolts shall be designed so that the bolt stress shall not exceed one third (1/3) of the minimum tensile stress of the bolt due to average packing compressive stress required to retain the maximum cold working pressure of the valve (CWP rating).
4.7 Operation
4.7.1 Plug valves shall be designed for operation by applying a wrench (sometimes called a lever), handle, or a handwheel to the stem either directly, or indirectly through the use of a gear mechanism or another mechanical device. The purchaser shall specify the type of operation required. The length of the wrench (or lever), handle, or the gear ratio of the gear mechanism shall be designed such that the input force required to operate the valve does not exceed the operator input force capability values given in MSS SP-91 using short-term force, a combined multiplier of 0.4 at the manufacturer’s maximum operating torque as defined in 4.4.3. In no case shall the input force exceed 360 N (80 lbf).
4.7.2 A wrench (or lever) shall be furnished as a separate item and shall be supplied only when specified in the purchase order. A wrench may be of an integral design or may consist of a head that fits onto the stem and is provided with a socket or another suitable means of accommodating an extended handle. The head shall be designed so that the handle can be permanently attached. The head shall be secured to the stem or operating mechanism with a set screw of ample size, or by another positive means.
4.7.3 A spoked handwheel shall be furnished with each gear-operated valve; webbed or disked handwheels shall not be used. Spokes that extend beyond the wheel rim (tiller type) are permissible.
4.7.4 Gear mechanisms may be operated manually or by means of an electric motor or another similar power device. Keys or pins shall be used to secure gears or pinions to shafts. On power-operated valves, the gear assembly shall be suitably guarded.
4.7.5 When specified in the purchase order, valves shall be furnished with a lockable device that accepts a purchaser-supplied lock that enables the valve to be locked in the open and closed positions. The lockable device shall be designed such that a lock with an 8 mm (/16 in.) diameter shank, not more than 100 mm (4 in.) long, can be inserted directly through appropriate holes and locked.