ASME B16.25:2012 pdf free downolad

ASME B16.25:2012 pdf free download.Buttwelding Ends.
3 WELDING BEVEL DESIGN
3.1 Bevels for Other Than GTAW Root Pass
(a) Components having nominal wall thicknesses of 3 mm (0.12 in.) and less shall have ends cut square or slightly chamfered.
(b) Components having nominal wall thicknesses over 3 mm (0.12 in.) to 22 mm (0.88 in.) inclusive shall have single angle bevels as illustrated in Fig. 2.
(c) Components having nominal wall thicknesses greater than 22 mm (0.88 in.) shall have compound angle bevels as illustrated in Fig. 3.
3.2 Bevels for GTAW Root Pass
(a) Components having nominal wall thicknesses of 3 mm (0.12 in.) and less shall have ends cut square or slightly chamfered.
(b) Components having nominal wall thicknesses over 3 mm (0.12 in.) to 10 mm (0.38 in.) inclusive shall have 37’/2-deg ± 2’4-deg bevels or slightly concave bevels (see Fig. 4).
(c) Components having nominal wall thicknesses over 10 mm (0.38 in.) to 25 mm (1.0 in.) inclusive shall have bevels as shown in Fig. 5.
(d) Components having nominal wall thicknesses greater than 25 mm (1.0 in.) shall have bevels as shown in Fig. 6.
3.3 Outside Diameter at Welding Ends
Dimension A shall be either that specified in the applicable component standard or that specified in the purchaser’s component specification. In the absence of a requirement for dimension A in a component standard or a purchaser’s specification, the values for dimension A in Table 1 or Table 1-1 may be used.
4 PREPARATION OF INSIDE DIAMETER OF WELDING END
4.1 General
Preparation of the inside diameter at the end of a component shall be in accordance with one of the following, as specified by the purchaser:
(a) Components to be welded without backing rings shall meet the requirements of the standard or specification for the component.
(b) Components to be welded using split or noncontinuous backing rings shall be contoured with a cylindrical surface at the end as shown in Fig. 2, illustration (b) and Fig. 3, illustration (b). If the backing ring contour is other than rectangular, details must be furnished by the purchaser.
(b) For components in smaller sizes and lower schedule numbers, it may be necessary to deposit weld metal on the inside diameter (ID.) or use thicker wall materials in order to machine the backing ring while maintaining required wall thickness. This condition may also arise when using material whose nominal dimensions indicate sufficient metal but whose actual ID., considering tolerances, is large enough to require additional metal.
5 TOLERANCES (See Figs. 2, 3, 5, and 6)
5.1 Dimension B
Values for the l.D. at the welding end [see dimension B, Fig. 2, illustrations (a) and (b) and Fig. 3, illustrations (a) and (b)J shall be as specified in the applicable standard or specification for the component.
5.2 Welding Bevels, Root Face, and Dimension C
Values of welding bevels, root face, and dimension C shall be as indicated in Figs. 2 through 6.