API St 609-2009 pdf download.Butterfly Valves: Double-flanged, Lug- and Wafer-type.
1 Scope 1.1 This standard covers design, materials, face-to-face dimensions, pressure-temperature ratings, and examination, inspection and test requirements for gray iron, ductile iron, bronze, steel, nickel-based alloy, or special alloy butterfly valves that provide tight shutoff in the closed position. The following two categories of butterfly valves are included. a) Category A—Manufacturer’s rated cold working pressure (CWP) butterfly valves, usually with a concentric disc and seat configuration. Sizes covered are NPS 2 to NPS 48 for valves having ASME Class 125 or Class 150 flange bolting patterns. b) Category B—ASME Class and pressure-temperature rated butterfly valves that have an offset seat and either an eccentric or a concentric disc configuration. These valves may have a seat rating less than the body rating. For lug and wafer, Class 150, 300, and 600, sizes covered are NPS 3 to NPS 24. For double-flanged long pattern, Class 150, 300, and 600, sizes covered are NPS 3 to NPS 36. For double-flanged short pattern, Class 150 and 300, sizes covered are NPS 3 to NPS 48. For double-flanged short pattern, Class 600, sizes covered are NPS 3 to NPS 24. 1.2 Valve configurations include double-flanged, lug- and wafer-types with facings that permit installation between ASME and MSS flanges that conform to the standards and specifications listed in Section 2. 2 Normative References The following referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies. Text in brackets after a publication title indicates a restriction on the classes to which the publication applies. API Standard 598, Valve Inspection and Testing API Standard 607, Fire Test for Soft-seated Quarter-turn Valves ASME B1.1 1 , Unified Inch Screw Threads [UN and UNR Thread Form] ASME B16.1, Gray Iron Pipe Flanges and Flanged Fittings
3 Pressure-temperature Ratings 3.1 Valve Rating Category A valves shall have a CWP rating that is the lesser of its shell rating, seat rating, or differential pressure rating. 3.2 Shell Rating 3.2.1 Category A valve bodies and related pressure boundary elements shall have the CWP rating assigned by the manufacturer. 3.2.2 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: a) for ductile iron, ASME B16.42; b) for cast copper alloys, ASME B16.24; c) for steel, nickel alloy, or special alloy material, ASME B16.34 (standard class). 3.3 Seat Rating 3.3.1 For Category B valves, the valve seat ratings for polytetrafluoroethylene (PTFE) and reinforced polytetrafluoroethylene (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. 3.3.2 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 specifications. Temperature limits shall be marked on the nameplate as required in 7.1.
4 Design 4.1 General 4.1.1 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 specified 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 conflict between ASME B16.34 and this standard, this standard shall prevail. 4.1.2 Fire-tested Valves If the purchaser specifies fire-tested valves, the valves shall be certified to have been tested to, and met, all of the performance requirements of API 607. Supporting documentation shall be made available to the purchaser upon request. 4.1.3 Lockable Device 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 both the open and closed positions. The lockable device shall be designed such that a lock with a 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 specified in the purchase order. 4.1.4 Disc Position Indication The indication of the position of the disc shall be integral with the valve shaft and shall be aligned with the valve disc. The indication may be accomplished by a mark on the shaft or by a shaft shape. The design shall ensure that a valve (and/or operator) cannot be assembled to falsely indicate the valve’s open and closed positions.