API 609:2004 pdf download

API 609:2004 pdf download.Butterfly Valves: Double Flanged, Lug- andWafer-Type.
Note I When salve body liners. sleeves, or O.ring seals act as lange-sealing surfaces. separate gaskets should not tie used unless speeihcally recommended by the manufacturer,
Note 2: Valves with liners that extend to the gasket seating surfaces should be bolted up with the disc in the partially open position.
4.3.2 Facc-to-facc dimensions far doubic Hanged valvcs are listed in Table 2-B for long pattern valves, or Table 2-C for short pattern salves.
4.3.3 Body contact faccs of cast iron, ductile iron, and cast copper alloy valves that require separate gaskets shall be finished as specified in MSS SP-6.
4.3.4 Body contact faces of steel or alloy valves thai require separate gaskets shall be finished as specified in
ASMF B 16.5.
4.4 DISC CLEARANCE
The manufacturer shall design the valve disc to provide suitable clearance, in accordance with the ASME class rating for the salve, the inside diameter of the connecting pipe or flange. and the criteria covered in the appendix to this standard.
Note: For lug- and wafer-type valves and some double flanged designs. thc disc will project beyond the body faccs when the disc is turned. The purchaser should review the design of the piping to ensure that there will be no interference between the disc and adjacent components such as the pipe lining, strainers, check valves, and other valves. During valve installation, the mating flanges shall be aligned helure linal tightening of the Ilange bolts to ensure proper valve operation and the seating of any seals and gaskets.
4.5 SHAFT AND SHAFT SEALS
4.5.1 The shaft to disc connection and all parts of the shaft within the pressure boundary shall, under torsional load. exceed the strength of the shaft that lies outside the pressure boundary by more than lOc. The determination of shaft strength shall be by calculation or testing.
4.5.2 The shaft and/or shaft retention shall be designed so that, if failure of the shaft to disc connection or of the shaft occurs, no portion of the shaft can be ejected from the valve as a result of internal pressure. The design shall not rely on actuation components (e.g.. gear operators. actuators, levers. etc.) to prevent shaft ejection.
4.5.3 The shalt-to—disc connection shall be designed tO prevent loosening due to vibration.
4.5.4 For Category B valves, the shaft shall have a surface finish of 32 microinchcs (0.80 micrometers) Ra or smoother in the area in contact with the packing. and the stuffing box shall have a surface finish of 125 micnjinchcs (3.2 micrometers) Ra or smoother. Measurement may be by visual and tactile comparison or by use of a stylus-type surface roughness measuring instrument (ASME B4ft I).
4.5.5 Category B valves shall have adjustable shaft packing. The packing mechanism shall allow packing adjustment while the valve is pressurized with line fluid.
4.6 PIPING CONNECTION EXTERNAL BOLT HOLES
4.6.1 Unless specified otherwise in the purchase order. lugs of lug-type valves shall be provided with tapped holes for studs or bolts,
4.6.2 Threaded body- flange holes for bolts I inch or less in diameter shall be drilled and tapped in accordance with ASME Bl.l. coarse-thread series, Class 2B. For bolts I 1/x inches or more in diameter, such holes shall be drilled and tapped in accordance ssith ASME B1.l. eight-thread series. Class 2B,
4.6.3 Threaded bolt holes shall allow full thread engagenwnt to a depth at least equal to the nominal bolt diameter:
however, when the bolt hole is adjacent to the shaft, engagement to a depth of 67% of the nominal bolt diameter is acceptable.
4.6.4 Typical bolting options for lug- and wafer- type valves are shown in Figure 1.
4.7 SEAT RETAINER—CATEGORY B VALVES ONLY
4.7.1 Seat retainer plates (designed per Figure 2) are separate plates intended to retain and compress the valve scat and shall be mechanically fastened to the valve body. Retaining fasteners shall be recessed to or below the flange gasket surface.
4.7.2 Gasket seating surface interruptions: Interruptions in the seating area of a centered ASME B16.2() spiral wound gasket for valve sites NPS 6 through 48 shall not exceed the limitations given in Figure 2. The permissible surface interruptions on smaller size valves shall be as agreed between purchaser and manufacturer hut shall not exceed 5()* of the gasket seating width.
Note: ‘The degree of interruption may affect the scalab.lity of a spiral-wound gaskel
4.7.3 All components of lug-ype and double flanged valves designated as suitable for bidirectional dead-end service shall be designed for the valve’s difierential pressure rating.