API STD 604 2004 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-base alloy, or special alloy butterßy valves that provide tight shutoff in the closed position and are suitable for ßow regulation. Two categories of butterßy valves are included: a. Category A: ManufacturerÕs rated cold working pressure (CWP) butterßy valves, usually with a concentric disc and seat conÞguration. Sizes covered are NPS 2 to NPS 48 for valves having ASME Class 125 or Class 150 ßange bolting patterns. b. Category B: Pressure-temperature rated butterßy valves that have an offset seat and either an eccentric or a concentric disc conÞguration. 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 ßanged long pattern, Class 150, 300, and 600, sizes covered are NPS 3 to NPS 36. For double ßanged short pattern, Class 150 and 300, sizes covered are NPS 3 to NPS 48. For double ßanged short pattern, Class 600, sizes covered are NPS 3 to NPS 24. 1.2 Valve conÞgurations include double ßanged, lug- and wafer-types with facings that permit installation between ASME and MSS ßanges that conform to the standards and speciÞcations listed in Section 2. 2 References The most recent edition or revision of the following stan- dards or speciÞcations shall, to the extent speciÞed in this standard, form a part of this standard. Text in brackets after a publication title indicates a restriction on the classes to which the publication applies.
3.3 SEAT RATING 3.3.1 For Category B valves the valve seat ratings for PTFE and RPTFE shall be at least equal to those listed in Table 3. For seating materials not listed in Table 3, seat ratings shall be agreed upon by the purchaser and 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 manufacturerÕs published speciÞcations. Temperature limits shall be marked on the nameplate as required in 7.1. 3.4 DIFFERENTIAL PRESSURE RATING A valveÕs differential pressure rating measures the valves capability to hold pressure from one side either at shutoff or in the partly open position with ßow in the line. 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 speciÞed in this standard. For materials not listed in B16.34, the applicable require- ments and design rules of B16.34 shall be used. In the event of a conßict between ASME B16.34 and this standard, this standard shall prevail. 4.1.2 Fire Tested Valves If the purchaser speciÞes Þre tested valves, the valves shall be certiÞed to have been tested to, and met, all of the perfor- mance requirements of API Standard 607. Supporting docu- mentation shall be made available to the purchaser upon request. 4.1.3 Lockable Device When speciÞed in the purchase order, valves shall be fur- nished with a lockable device that accepts a purchaser-sup- plied 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 5 / 16 -in. (8-mm) diameter shank, not more than 4 in. (100 mm) long, can be inserted directly through appropriate holes and locked.
4.2 BODY 4.2.1 The minimum body-wall thickness shall comply with the applicable ASME B16 standard listed in Section 2 based on the body material. If the applicable standard covers Þttings for a particular material, the valve minimum wall thickness shall be as speciÞed for Þttings. The valve design shall be structurally suitable for its stated pressure and temperature limits, taking into account that localized thinning may be nec- essary between the shaft bore in the body and the adjacent bolt holes. Such sections shall be designed in accordance with the requirements of ASME B16.34. 4.2.2 When a wafer-type valve is installed between piping ßanges and the disc is in the closed position, the valve shall be self-centering, that is, designed to center itself within the bolt circle by using the valveÕs outside diameter, or by means of integral or attached alignment devices. 4.2.3 End ßanges for double ßanged valves shall be inte- grally cast or forged with the body; however, ßanges may be attached by full-penetration butt welding if agreed to by the purchaser. End ßanges attached by welding shall conform to ASME B16.5 and have butt-welding ends for use without backing rings. Welds shall conform to ASME B31.3, as shall qualiÞcations for the welding procedure and the welder or welding operator. The Þnished weld thickness shall not be less than the minimum body-wall thickness.