ASME B16.34-2009 pdf download

ASME B16.34-2009 pdf download.Valves—Flanged, Threaded, and Welding End.
5.2.2 Responsibility. When service conditions dic- tate the implementation of special material require- ments, e.g., using a Group 2 material above 538°C (1,000°F), it is the user’s responsibility to so specify to the manufacturer in order to ensure compliance with metallurgical requirements listed in the end notes to Table 1 and the notes in Table 2. 5.3 Electrical Continuity Internal parts that are insulated from the valve body may build up a static electric charge. Anexample is a ball valve with seats and seals of nonconductive materials. When service conditions require electrical continuity to preventstatic discharge, the useris responsible for speci- fying static grounding. 5.4 Flange Removal When an end flange is removed from a flanged-end valve body casting to make a welding-end valve casting, discontinuities may be observed that would not have been detrimental in the flanged body casting. The valve manufacturer that removes an end flange from a valve body casting during the course of manufacture has responsibility for the acceptability of the resultant weld- ing-end valve casting. This responsibility includes pres- sure testing the resultant weld-end valve in accordance with section 7. 6 DIMENSIONS 6.1 Body Dimensions 6.1.1 Wall Thickness. For inspection purposes, the wall thickness ofvalve bodies atthe time ofmanufacture except as indicated in paras. 6.1.3 through 6.1.7, 6.2, and 6.7, shall be no less than the minimum values t m either as shown in Table 3A or Table 3B or calculated using the equation shown in Mandatory Appendix VI (which yield essentially the same result). Linear interpolation may be used for wall thickness values intermediate to those listed or calculated. See Nonmandatory Appendix B, section B-5 for an explanation of the interpolation procedure. The minimum thickness requirement for the body wall is applicable only as measured from internal wetted surfaces. Minimumwall thickness determination shall not include liners, linings, or cartridges. 6.1.2 Inside Diameter. For the purpose of determin- ing wall thickness, t m , using Table 3A or Table 3B, or the equations in Mandatory Appendix VI, the inside diameter, d, shall be in accordance with the following requirements: (a) The inside diameter, d, shall be the minimum diameter of the flow passage but not less than 90% of the basic inside diameter at the valve end subject to the 6 considerations listed in paras. 6.1.2(b) through 6.1.2(f). (b) For socket welding- and threaded-end valves, the socket or thread diameters and associated counterbores or threaded bores need not be considered in establishing the value of d (see paras. 6.2.3 and 6.2.4). (c) For valve bodies of multipiece construction, e.g., a three-piece ball valve [see Fig. 1, illustration (c)], where the body consists of a central core piece to which are affixed two end pieces, the inside diameter, d, is deter- mined as (1) for the end pieces, the value of d shall be in accordance with para. 6.1.2(a). (2) for the central core piece, the value of d shall be the inside diameter of the core piece. If the core piece wall has axial holes, whether through- or partial- threaded, then the inner and outer ligaments shall also meet the requirements of dimensions fand g of Fig. 17. (d) For the special case of valves used between high- and low-pressure sections of a system where an end connection for a thinner pipe wall (or lower Class flange) on one end than on the other, the inside diameter, d, shall be based on the end connection with the heavier pipe wall (or higher Class flange). The valve wall thick- ness, t m , shall be that associated with the higher Class rating. (e) Localized variations of inside diameter associated with transitions to weld preparations need not be con- sidered. Note, however, limitations ofproximity ofbody neck in para. 6.1.5. (f) Wherelinings,liners, orcartridgesareused to form the flow passage or portions of the flow passage, the inside diameter, d, shall be that at the lining-body, liner-body, or cartridge-body interface. (g) For inside diameters that lie between diameters listed in Table 3, the minimum wall thickness, t m , may be determined by linear interpolation using the method of para. B-4.4. 6.1.3 Valve Body Necks. For inspection purposes, the wall thickness of valve body necks at the time of manufacture shall be no less than the minimum values determined by the following: (a) Valve body necks, except for the special cases described in paras. 6.1.3(b), (c), and (d), shall maintain the minimum wall thickness as described in paras. 6.1.1 and 6.1.2 within a region of 1.1 ? dt m measured from the outside of the body run along the neck direction. The diameter, d, is as defined in para. 6.1.2, and t m is the minimum wall thickness as shown in Table 3A or Table 3B. Minimum wall thickness requirements are applicable to and measured from internally wetted sur- faces, e.g., up to the point where the body-bonnet seal is affected.