Dimensions of lap joint stub ends ASME B16.9

NPS	OD of Barrel		Long Pattern	Short Pattern	Radius of	Diameter of
NPS	Max	Min	Length, F	Length, F	Fillet, R	Lap, G
1/2	22.8	20.5	76	51	3	35
3/4	28.1	25.9	76	51	3	43
1	35	32.6	102	51	3	51
1 ¼	43.6	41.4	102	51	5	64
1 ½	49.9	47.5	102	51	6	73
2	62.4	59.5	152	64	8	92
2 ½	75.3	72.2	152	64	8	105
3	91.3	88.1	152	64	10	127
3 ½	104	100.8	152	76	10	140
4	116.7	113.5	152	76	11	157
5	144.3	140.5	203	76	11	186
6	171.3	167.5	203	89	13	216
8	222.1	218.3	203	102	13	270
10	277.2	272.3	254	127	13	324
12	328	323.1	254	152	13	381
14	359.9	354.8	305	152	13	413
16	411	405.6	305	152	13	470
18	462	456	305	152	13	533
20	514	507	305	152	13	584
22	565	558	305	152	13	641
24	616	609	305	152	13	692
Notes: 1) Gasket face finish shall be in accordance with ASME B16.5 for raised face flanges. 2) The lap thickness T shall not be less than nominal pipe wall thickness. 3) When short pattern stub ends are used with larger flanges in Classes 300 and 600,with most sizes in Classes 900 and higher,and when long pattern stub ends are used with larger flanges in Classes 1500 and 2500,it may necessary to increase the length of the stub ends in order to avoid covering the weld with the flange.Such increases in length shall be a matter of agreement between the manufacturer and purchaser. 4) When special facings such as tongue and groove,male and female,etc.,are employed,additional lap thickness must be provided and such additional thickness shall be in addition to (not included in)the basic length F.