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.
4.4 Diferential Pressure Rating Diferential pressure rating shall not exceed the seat pressure rating. Temperature limits shall be marked on the nameplate as required in 8.1 f). For seating materials not listed in Table 1, seat ratings shall be established by the manufacturer.4.3.2 Valves furnished with internal liners, encapsulation, resilient seating materials, or a combination of these features shall have pressure-temperature limits conforming to the valve manufacturer’s published specifcations. 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. 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. 4.2 Shell Rating 4.2.1 Category A valve bodies and related pressure boundary elements shall have the CWP rating assigned by the manufacturer. 4 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. 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). 3.5 pressure boundary element Comprises the shell and related bolting that forms a part of the pressure boundary (see Annex C). The dimensionless size identifcation number does not represent a measurable value and is not used for calculation purposes. The dimensionless number may be used as a valve size identifer without the prefx “NPS”.
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. 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. 3.2 cryogenic? service Unless a diferent temperature is specifed by the purchaser, valves required to operate at or below −73 ☌ (−100 ☏) are in cryogenic service. 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. 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. It comprises the letters “Class” followed by a dimensionless whole number. 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.
Api 609 category b pdf pdf#
API Std 609 pdf free download.Butterfy Valves: Double-fanged, Lug- and Wafer-type, and Butt-welding Ends.ģ? Terms? and? Defnitions For the purpose of this document, the following terms and defnitions apply.
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