ASME B16.25-2017 pdf – Buttwelding Ends
ASME B16.25-2017 pdf – Buttwelding Ends.
3 WELDING BEVEL DESIGN
3.1 Bevels for Other Than GTAW Root Pass
j’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 Figure 2.
(c) Components having nominal wall thicknesses greater than 22 mm (0,88 In.) shall have compound angle bevels as illustrated In Figure 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 lit) inclusive shall have
37-deg ± 2’/2-deg bevels or slightly concave bevels (see
(c) Components having nominal wall thicknesses over 10 mm (0.38 in.) to 2S mm (1.0 in.) inclusive shall have bevels as shown In Figure 5.
N,) Components having nominal wall thIcknesses greater than 25 mm (1.0 in.) shall have bevels as shown in Figure 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 I or Table I-I may be used.
4 PREPARATION OF INSIDE DIAMETER OF WELDING END
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 specltlcation for the component.
(b1 Components to be welded using split or noncontinuous backing rings shall be contoured with a cylindrical surface at the end as shown in Figure 2, illustration (b) and FIgure 3. illustration
(a) For pipe or tubing varying from the ASTM A106 and A335 types, having different wall thickness and/or outside diameter tolerances (such as forged and bored pipe), the foregoing equations may be Inapplicable. Equations (1) and (2) may he used to determine C for these applications. The purchaser shall specify the C dimension when Tables 1 and 1.1 data do not apply
(bl For components In smaller sizes and lower schcd• ole numbers, It may be necessary to deposit weld metal on the inside diameter (l.D.) 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 sumclent metal but whose actual lD considering toler• ances, is large enough to require additional metal.
See Figures 2. 3. 5. and 6
5.1 DimensIon B
Values for the l.D. at the welding end Isee dimension B, Figure 2. illustrations (a) and (b) and Figure 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 lace, and dimension C shall be as indicated in Figures 2 through 6.