API St 609-2021 pdf free download

API St 609-2021 pdf free download.Butterfy Valves: Double-fanged, Lug- and Wafer-type, and Butt-welding Ends.
3? Terms? and? Defnitions For the purpose of this document, the following terms and defnitions apply. 3.1 Class An alphanumeric designation that is used for reference purposes relating to valve pressure-temperature capability, taking into account valve material mechanical properties and valve dimensional characteristics. It comprises the letters “Class” followed by a dimensionless whole number. The number following the letters “Class” does not represent a measurable value and is not used for calculation purposes except where specifed in this standard. The allowable pressure for a valve having a class number depends on the valve material and its application temperature and is found in tables of pressure-temperature ratings. 3.2 cryogenic? service Unless a diferent temperature is specifed by the purchaser, valves required to operate at or below −73 °C (−100 °F) are in cryogenic service. 3.3 dead-end? service A condition that may occur after the companion fange and/or piping are removed from one side of a valve. 3.4 NPS An alphanumeric designation of size that is common for components used in a piping system, used for reference purposes, comprising the letters “NPS” followed by a dimensionless number indirectly related to the physical size of the bore or outside diameter of the end connection as appropriate. The dimensionless number may be used as a valve size identifer without the prefx “NPS”. The dimensionless size identifcation number does not represent a measurable value and is not used for calculation purposes. 3.5 pressure boundary element Comprises the shell and related bolting that forms a part of the pressure boundary (see Annex C). 3.6 shell Comprises the body, cover, bonnet, bonnet extension, and seat retainer that constitutes the pressure boundary of an API 609 valve (see Annex C). 4 Pressure-temperature Ratings 4.1 Valve Rating Category A valves shall have a CWP rating that is the lesser of its shell rating, seat rating, or diferential pressure rating. 4.2 Shell Rating 4.2.1 Category A valve bodies and related pressure boundary elements shall have the CWP rating assigned by the manufacturer. 4.2.2 Category B valve bodies and related pressure boundary elements shall have the pressure-temperature rating as listed in one of the following standards according to the valve’s body material: — for ductile iron, ASME B16.42; — for cast copper alloys, ASME B16.24; — for steel, nickel alloy, or special alloy material, ASME B16.34. 4.3 Seat Rating 4.3.1 For Category B valves, the valve seat ratings for polytetrafuoroethylene (PTFE) or modifed PTFE and reinforced polytetrafuoroethylene (RPTFE) or modifed RPTFE shall be at least equal to those listed in Table 1. For seating materials not listed in Table 1, seat ratings shall be established by the manufacturer.
5 Design 5.1 General 5.1.1 Category B Valves Valves manufactured in accordance with this standard shall meet the requirements of ASME B16.34 for Standard class and any additional requirements as specifed in this standard. For materials not listed in ASME B16.34, the applicable requirements and design rules of ASME B16.34 shall be used. In the event of a confict between ASME B16.34 and this standard, this standard shall prevail. 5.1.2 Fire-tested Valves If the purchaser specifes fre-tested valves, the valve’s design shall have been type tested and certifed to meet all performance requirements of API 607. Fire test report shall be made available to purchaser upon request. 5.1.3 Fugitive Emissions Tested Valves If the purchaser specifes fugitive emission valves, the valve’s design shall have been type tested and certifed to meet all performance requirements of API 641. Fugitive emission test report shall be made available to purchaser upon request. 5.1.4 Cryogenic Service Valves required to operate in cryogenic service shall meet the additional requirements specifed in ANSI/MSS SP-134. 5.1.5 Lockable Device When specifed 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 both the open and closed positions. The lockable device shall be designed such that a lock with an 8 mm ( 5 /16 in.) diameter shank, not more than 100 mm (4 in.) long, can be inserted directly through appropriate holes and locked. Provisions for a lockable device are permitted even when it is not specifed in the purchase order.