PIPE FLANGES AND FLANGED FITTINGS
ASME B16.5-2003
7.5.3 7.5.3 Backing Backing Ring Contact Contact Surface. Surface. Required tolerances for the bore of the backing ring contact surface of welding neck flanges, dimension C of Figs. 10 and 11 (Figs. F10 and F11 of Annex F) are as follows. 2 ≤ NPS ≤ 24 +0.2 +0.25, 5, −0.0 −0.0 mm (+ 0.01 0.01,, −0.0 −0.0 in.) in.)
(b) Center-to-En Center-to-Endd (Ring Joint): NPS ≤ 10 ±1.0 mm (±0.03 in.) NPS ≥ 12 ±1.5 mm (±0.06 in.) (c) Contact Contact Surface-to-Conta Surface-to-Contact ct Surface Other Than Ring Joint: NPS ≤ 10 ±2.0 mm (±0.06 in.) NPS ≥ 12 ±3.0 mm (±0.12 in.)
7.5.4 7.5.4 Hub Thickn Thickness. ess. Despite the tolerances specified for dimensions A and B, the thickness of the hub at the welding end shall not be less than 87 1 ⁄ 2% of the nominal thickn thickness ess of the pipe, pipe, havin having g an under under tolera tolerance nce of 12.5% 12.5% for the pipe wall thickness to which the flange is to be attached, or the minimum wall thickness as specified by the purchaser. purchaser.
(d) End-to-End (Ring Joint): NPS ≤ 10 ±2.0 mm (±0.06 in.) NPS ≥ 12 ±3.0 mm (±0.12 in.)
7.3 Facings Facings Required tolerances for various flange and flanged fitting facings are as follows: (a) Inside and outside diameter of large and small tongue and groove and female, ±0.5 mm (±0.02 in.). (b) Outside diameter, 2.0 mm (0.06 in.) raised face, ±1.0 mm (±0.03 in.). (c) Outside diameter, 7.0 mm (0.25 in.) raised face, ±0.5 mm (±0.02 in.). (d) Ring joint groove tolerances are shown in Table 5 (Table F5 of Annex F).
7.6 Length Through Through Hub on Welding Neck Neck Flanges The required tolerances for the length through hubs on welding neck flanges are as follows. NPS ≤ 4 ±1.5 mm (±0.06 in.) 5 ≤ NPS ≤ 10 +1.5 +1.5,, −3.0 −3.0 mm (+0.06 (+0.06,, −0.12 −0.12 in.) in.) NPS ≥ 12 +3.0 +3.0,, −5.0 −5.0 mm (+0. (+0.12 12,, −0.1 −0.188 in.) in.)
7.7 Flange Flange Bore Bore 7.7.1 Lapped, Slip-on, Slip-on, and Socket Socket Welding Flange Bores. The required tolerances for lapped, slip-on, and socket welding flange bores are as follows. NPS ≤ 10 +1.0, .0, −0.0 −0.0 mm (+0.03, −0.0 in.) in.) NPS ≥ 12 +1.5, .5, −0.0 −0.0 mm (+ 0.06 .06, −0.0 in.)
7.4 Flange Thickness Thickness Requiredtolerance Requiredtolerancess for flange flange thickness thickness are as follows. follows. NPS ≤ 18, 18, +3.0 +3.0,, −0.0 −0.0 mm (+0. (+0.12 12,, −0.0 −0.0 in.) in.) NPS ≥ 20, 20, +5.0 +5.0,, −0.0 −0.0 mm (+0. (+0.19 19,, −0.0 −0.0 in.) in.)
7.7.2 Counterbores, Counterbores, Threaded Flanges. The required tolerances for threaded flange counterbores are as follows. NPS ≤ 10 +1.0, .0, −0.0 −0.0 mm (+0.03, −0.0 in.) in.) NPS ≥ 12 +1.5, .5, −0.0 −0.0 mm (+0.06, −0.0 in.) in.)
The plus tolerance tolerance is applicable applicable to bolting bearing bearing surfaces whether as-forged, as-cast, spot-faced or backfaced. See para. 6.6.
7.5 Weldin Welding g End Flange Flange Ends and Hubs
7.7.3 7.7.3 Counter Counterbores, bores, Socket Socket Welding Welding Flanges. Flanges. The required tolerances for socket end counterbores is as follows. 1 ⁄ 2 ≤ NPS ≤ 3 ±0.25 mm (±0.010 in.)
7.5.1 Outside Outside Diameter. Required tolerances for the nominal outside diameter dimension A of Figs. 8 and 9 (Figs. F8 and F9 of Annex F) of welding ends of welding neck flanges are as follows: NPS ≤ 5 +2.0 +2.0,, −1.0 −1.0 mm (+0.0 (+0.09, 9, −0.0 −0.033 in.) in.) NPS ≥ 6 +4.0 +4.0,, −1.0 −1.0 mm (+0.1 (+0.16, 6, −0.0 −0.033 in.) in.)
7.8 Drilling Drilling and Facing Facing
7.5.2 Inside Diameter. Diameter. Required Required tolerances tolerances for the nominal inside diameter of welding ends of welding neck flanges and smaller bore of socket welding flanges (dimension B in the referenced figures) are as follows: For Figs. 8 and 9 (Figs. F8 and F9 of Annex F) the tolerances are NPS ≤ 10 ±1.0 mm (±0.03 in.) 12 ≤ NPS ≤ 18 ±1.5 mm (±0.0 ±0.066 in.) NPS ≥ 20, 20, +3.0 +3.0,, −1.5 −1.5 mm (+0. (+0.12 12,, −0.0 −0.066 in.) in.)
7.8.1 Bolt Circle Circle Diameter. The required tolerance for all bolt circle diameters is ±1.5 mm (±0.06 in.) 7.8.2 Bolt 7.8.2 Bolt Hole Hole to Bolt Bolt Hole. The required tolerance for the center-to-ce center-to-center nter of adjacent adjacent bolt holes is ±0.8 mm (±0.03 in.) 7.8.3 7.8.3 Bolt Circle Circle Concentr Concentricity icity.. The required required tolerances for concentri concentricity city between the flange flange bolt circle diameter and machined facing diameters are as follows. NPS ≤ 21 ⁄ 2 0.8 mm (0.03 in.) NPS ≥ 3 1.5 mm (0.06 in.)
For Fig. 10 (Fig. F10 of Annex F) the tolerances are NPS ≤ 10 +0.0 +0.0,, −1.0 −1.0 mm (+0. (+0.0, 0, −0.0 −0.033 in.) in.) NPS ≥ 12 +0.0 +0.0,, −1.5 −1.5 mm (+0. (+0.0, 0, −0.0 −0.066 in.) in.) 13