Lap Joint Flange

Lap Joint Flanges (LJ Flanges/Lapped Joint Flanges) are used on piping fitted with lapped pipe or with lap joint stub ends the combined initial cost of the two items being approximately one-third higher than that of comparable welding neck flanges. Their pressure-holding ability is little, if any, better than that of slip-on flanges and the fatigue life of the assembly is only one-tenth that of welding neck flanges. The lap joint flange with the stub end assembly are normally used in systems requiring frequent dismantling for inspection and cleaning and where the ability to swivel flanges and to align bolt holes materially eases the erection of large diameter or unusually stiff piping. These flanges are also used in applications where there is a need to facilitate bolt alignment. Their use at points where severe bending stress occurs should be avoided.
Yaang has 3 warehouses in Wenzhou, Wuxi and Hebei. As one of the piping solution providers, Yaang has been committed to providing one-stop solutions for projects in the fields of oil and gas, water, renewable energy and infrastructure. With years’ consistent dedication and innovation, our reliable, cost-effective and environment-friendly solutions have won clients’ wide recognition.

China Lap Joint Flange manufacturer Yaang supplies Lap Joint Flanges , LJ Flanges in materials of stainless steel, carbon steel, alloy steel etc.

• Class 150 Lap Joint Flange
• Class 300 Lap Joint Flange
• Class 400 Lap Joint Flange
• Class 600 Lap Joint Flange
• Class 900 Lap Joint Flange
• Class 1500 Lap Joint Flange
• Class 2500 Lap Joint Flange

Size: 1/2″ – 56″ (DN15 to DN1,400)
Pressure:
American standard series: CLASS 150, CLASS 300, CLASS 400, CLASS 600, CLASS 900, CLASS 1500, CLASS 2500 
European standard series: PN 2.5, PN 6, PN 10, PN 16, PN 25, PN 40, PN 63, PN 100, PN 160, PN 250, PN 320, PN 400
Flange Facing Types: American series: Flat Face(FF), Raised Face(RF), Groove(G), Male and Female Face(MFM), Ring Type Joint (RTJ)
Material: 
Carbon steel: A105 
Alloy steel: A182F 1-F 2-F 5-F 9-F 10-F 91-F 92-F 122-F 911-F 11-F 12-F 21-F 22
Stainless steel: A182 304-304H-304L-304N-304LN 316-316H-316L-316N-316LN 321-321H-347-347H
Standard: 
GB/T9112-2000
GB/T9116 1-2000 GB/T9116 2-2000 GB/T9116 3-2000 GB/T9116 4-2000
GB/T9124-2000
SH/T3406-1996
GD2000 GD87-1101
HG/T20592-2009 HG/T20614-2009
HG/T20615-2009 HG/T20623-2009 HG/T20635-2009
ASME B16.5-2009
EN1092-1-2007 EN1759-1-2004
BS 1560-3 1-1989 BS 4504-3 1-1989
AFNOR NF E29-200-1-2007
ISO 7005-1-1992
AS2219-2000
JIS B2220-2004

Lap Joint flange dimensions are covered in ASME B16.5 – which covers Pipe Flanges and Flanged Fittings for size NPS ½” to 24” for above NPS 26” to 60” it should be as per ASME B16.47.

During dimensional inspection of flange, you should check for

• Outer & Inner Diameter of body
• Bolt Circle & Bolt hole Diameter
• Length of the Hub
• Straightness and alignment of the bolt hole

Class 150 Lap Joint Flange Dimensions

Size in Inch	Size in mm	Outer Diameter	Flange Thick.	Lapped Thick.	Lapped ID	PCD	Lapped Thick.	Lapped Radius	No of Bolts	Bolt Size UNC	Machine Bolt Length	RF Stud Length	Hole Size	ISO Stud Size	Weight in kg
		A	B	C	D	E	G
1/2	15	90	30	16	22.9	60.3	11.2	3	4	1/2	50	55	5/8	M14	0.8
3/4	20	100	38	16	28.2	69.9	12.7	3	4	1/2	50	65	5/8	M14	0.9
1	25	110	49	17	34.9	79.4	14.3	3	4	1/2	55	65	5/8	M14	0.9
1 1/4	32	115	59	21	43.7	88.9	15.9	5	4	1/2	55	70	5/8	M14	1.4
1 1/2	40	125	65	22	50	98.4	17.5	6	4	1/2	65	70	5/8	M14	1.4
2	50	150	78	25	62.5	120.7	19.1	8	4	5/8	70	85	3/4	M16	2.3
2 1/2	65	180	90	29	75.4	139.7	22.3	8	4	5/8	75	90	3/4	M16	3.2
3	80	190	108	30	91.4	152.4	23.9	10	4	5/8	75	90	3/4	M16	3.7
3 1/2	90	215	122	32	104.1	177.8	23.9	11	8	5/8	75	90	3/4	M16	5
4	100	230	135	33	116.8	190.5	23.9	11	8	5/8	75	90	3/4	M16	5.9
5	125	255	164	36	144.4	215.9	23.9	11	8	3/4	85	95	7/8	M20	6.8
6	150	280	192	40	171.4	241.3	25.4	13	8	3/4	85	100	7/8	M20	8.6
8	200	345	246	44	222.2	298.5	28.6	13	8	3/4	90	110	7/8	M20	13.7
10	250	405	305	49	277.4	362	30.2	13	12	7/8	100	115	1	M24	19.5
12	300	485	365	56	328.2	431.8	31.8	13	12	7/8	100	120	1	M24	29
14	350	535	400	79	360.2	476.3	35	13	12	1	115	135	1 1/8	M27	41
16	400	595	457	87	411.2	539.8	36.6	13	16	1	115	135	1 1/8	M27	54
18	450	635	505	97	462.3	577.9	39.7	13	16	1 1/8	125	145	1 1/4	M30	59
20	500	700	559	103	514.4	635	42.9	13	20	1 1/8	140	160	1 1/4	M30	75
24	600	815	663	111	616	749.3	47.9	13	20	1 1/4	150	170	1 3/8	M33	100

Class 300 Lap Joint Flange Dimensions

Size in Inch	Size in mm	Outer Diameter	Flange Thick.	Lapped Thick.	Lapped ID	PCD	Lapped Thick.	Lapped Radius	No of Bolts	Bolt Size UNC	Machine Bolt Length	RF Stud Length	Hole Size	ISO Stud Size	Weight in kg
		A	B	C	D	E	G
1/2	15	95	38	22	22.9	66.7	14.3	3	4	1/2	55	65	5/8	M14	1.2
3/4	20	115	48	25	28.2	82.6	15.9	3	4	5/8	65	75	3/4	M16	1.4
1	25	125	54	27	34.9	88.9	17.5	3	4	5/8	65	75	3/4	M16	1.4
1 1/4	32	135	64	27	43.7	98.4	19.1	5	4	5/8	70	85	3/4	M16	1.8
1 1/2	40	155	70	30	50	114.3	20.7	6	4	3/4	75	90	7/8	M20	2.7
2	50	165	84	33	62.5	127	22.3	8	8	5/8	75	90	3/4	M16	3.2
2 1/2	65	190	100	38	75.4	149.2	25.4	8	8	3/4	85	100	7/8	M20	4.6
3	80	210	117	43	91.4	168.3	28.6	10	8	3/4	90	110	7/8	M20	5.9
3 1/2	90	230	133	44	104.1	184.2	30.2	11	8	3/4	95	110	7/8	M20	7.7
4	100	255	146	48	116.8	200	31.8	11	8	3/4	95	115	7/8	M20	10
5	125	280	178	51	144.4	235	35	11	8	3/4	110	120	7/8	M20	12.7
6	150	320	206	52	171.4	269.9	36.6	13	12	3/4	110	120	7/8	M20	17.7
8	200	380	260	62	222.2	330.2	41.3	13	12	7/8	120	140	1	M24	26
10	250	445	321	95	277.4	387.4	47.7	13	16	1	140	160	1 1/8	M27	36
12	300	520	375	102	328.2	450.8	50.8	13	16	1 1/8	145	170	1 1/4	M30	52
14	350	585	425	111	360.2	514.4	54	13	20	1 1/8	160	180	1 1/4	M30	75
16	400	650	483	121	411.2	571.5	57.2	13	20	1 1/4	165	190	1 3/8	M33	86
18	450	710	533	130	462.3	628.6	60.4	13	24	1 1/4	170	195	1 3/8	M33	113
20	500	775	587	140	514.4	685.8	63.5	13	24	1 1/4	185	205	1 3/8	M33	143
24	600	915	702	153	616	812.8	69.9	13	24	1 1/2	205	230	1 5/8	M39	216

Class 400 Lap Joint Flange Dimensions

Size in Inch	Size in mm	Outer Diameter	Flange Thick.	Lapped Thick.	Lapped ID	PCD	Lapped Thick.	Lapped Radius	No of Bolts	Bolt Size UNC	RF Stud Length	Hole Size	ISO Stud Size	Weight in kg
		A	B	C	D	E	G
1/2	15	95	38	22	22.9	66.7	14.3	3	4	1/2	75	5/8	M14	1.3
3/4	20	115	48	25	28.2	82.6	15.9	3	4	5/8	90	3/4	M16	1.5
1	25	125	54	27	34.9	88.9	17.5	3	4	5/8	90	3/4	M16	1.8
1 1/4	32	135	64	29	43.7	98.4	20.7	5	4	5/8	95	3/4	M16	2.3
1 1/2	40	155	70	32	50	114.3	22.3	6	4	3/4	110	7/8	M20	3.2
2	50	165	84	37	62.5	127	25.4	8	8	5/8	110	3/4	M16	4.1
2 1/2	65	190	100	41	75.4	149.2	28.6	8	8	3/4	120	7/8	M20	5.9
3	80	210	117	46	91.4	168.3	31.8	10	8	3/4	125	7/8	M20	7.3
3 1/2	90	230	133	49	104.1	184.2	35	10	8	7/8	140	1	M24	9.6
4	100	255	146	51	116.8	200	35	11	8	7/8	140	1	M24	11.8
5	125	280	178	54	144.5	235	38.1	11	8	7/8	145	1	M24	14.1
6	150	320	206	57	171.4	269.9	41.3	13	12	7/8	150	1	M24	20
8	200	380	260	68	222.2	330	47.7	13	12	1	170	1 1/8	M27	31
10	250	445	321	102	277.4	387.4	54	13	16	1 1/8	190	1 1/4	M30	42
12	300	520	375	108	328.2	450.8	57.2	13	16	1 1/4	205	1 3/8	M33	59
14	350	585	425	117	360.2	514.4	60.4	13	20	1 1/4	210	1 3/8	M33	82
16	400	650	483	127	411.2	571.5	63.5	13	20	1 3/8	220	1 1/2	M36	107
18	450	710	533	137	462.3	628.6	66.7	13	24	1 3/8	230	1 1/2	M36	130
20	500	775	587	146	514.4	685.8	69.9	13	24	1 1/2	240	1 3/4	M39	157
24	600	915	702	159	616	812.8	76.2	13	24	1 3/4	265	1 7/8	M45	232

Class 600 Lap Joint Flange Dimensions

Size in Inch	Size in mm	Outer Diameter	Flange Thick.	Lapped Thick.	Lapped ID	PCD	Lapped Thick.	Lapped Radius	No of Bolts	Bolt Size UNC	RF Stud Length	Hole Size	ISO Stud Size	Weight in kg
		A	B	C	D	E	G
1/2	15	95	38	22	22.9	66.7	14.3	3	4	1/2	75	5/8	M14	1.3
3/4	20	115	48	25	28.2	82.6	15.9	3	4	5/8	90	3/4	M16	1.4
1	25	125	54	27	34.9	88.9	17.5	3	4	5/8	90	3/4	M16	1.8
1 1/4	32	135	64	29	43.7	98.4	20.7	5	4	5/8	95	3/4	M16	2.3
1 1/2	40	155	70	32	50	114.3	22.3	6	4	3/4	110	7/8	M20	3.2
2	50	165	84	37	62.5	127	25.4	8	8	5/8	110	3/4	M16	4.1
2 1/2	65	190	100	41	75.4	149.2	28.6	8	8	3/4	120	7/8	M20	5.9
3	80	210	117	46	91.4	168.3	31.8	10	8	3/4	125	7/8	M20	7.3
3 1/2	90	230	133	49	104.1	184.2	35	11	8	7/8	140	1	M24	9.6
4	100	275	152	54	116.8	215.9	38.1	11	8	7/8	145	1	M24	16.8
5	125	330	189	60	144.4	266.7	44.5	11	8	1	165	1 1/8	M27	29
6	150	355	222	67	171.4	292.1	47.7	13	12	1	170	1 1/8	M27	36
8	200	420	273	76	222.2	349.2	55.6	13	12	1 1/8	190	1 1/4	M30	52
10	250	510	343	111	277.4	431.8	63.5	13	16	1 1/4	215	1 3/8	M33	77
12	300	560	400	117	328.2	489	66.7	13	20	1 1/4	220	1 3/8	M33	91
14	350	605	432	127	360.2	527	69.9	13	20	1 3/8	235	1 1/2	M36	105
16	400	685	495	140	411.2	603.2	76.2	13	20	1 1/2	255	1 5/8	M39	150
18	450	745	546	152	462.3	654	82.6	13	20	1 5/8	275	1 3/4	M42	182
20	500	815	610	165	514.4	723.9	88.9	13	24	1 5/8	285	1 3/4	M42	232
24	600	940	718	184	616	838.2	101.6	13	24	1 7/8	330	2	M48	332

Class 900 Lap Joint Flange Dimensions

Size in Inch	Size in mm	Outer Diameter	Flange Thick.	Lapped Thick.	Lapped ID	PCD	Lapped Thick.	Lapped Radius	No of Bolts	Bolt Size UNC	RF Stud Length	Hole Size	ISO Stud Size	Weight in kg
		A	B	C	D	E	G
1/2	15	120	38	32	22.9	82.6	22.3	3	4	3/4	110	7/8	M20	1.8
3/4	20	130	44	35	28.2	88.9	25.4	3	4	3/4	115	7/8	M20	2.3
1	25	150	52	41	34.9	101.6	28.6	3	4	7/8	125	1	M24	3.6
1 1/4	32	160	64	41	43.7	111.1	28.6	5	4	7/8	125	1	M24	4.1
1 1/2	40	180	70	44	50	123.8	31.8	6	4	1	140	1 1/8	M27	5.5
2	50	215	105	57	62.5	165.1	38.1	8	8	7/8	145	1	M24	11.5
2 1/2	65	245	124	64	75.4	190.5	41.3	8	8	1	160	1 1/8	M27	16.5
3	80	240	127	54	91.4	190.5	38.1	10	8	7/8	145	1	M24	12
4	100	290	159	70	116.8	235	44.5	11	8	1 1/8	170	1 1/4	M30	24
5	125	350	190	79	144.4	279.4	50.8	11	8	1 1/4	190	1 3/8	M33	38
6	150	380	235	86	171.4	317.5	55.6	13	12	1 1/8	190	1 1/4	M30	50
8	200	470	298	114	222.2	393.7	63.5	13	12	1 3/8	220	1 1/2	M36	78
10	250	545	368	127	277.4	469.9	69.9	13	16	1 3/8	235	1 1/2	M36	112
12	300	610	419	143	328.2	533.4	79.4	13	20	1 3/8	255	1 1/2	M36	148
14	350	640	451	156	360.2	558.8	85.8	13	20	1 1/2	275	1 5/8	M39	182
16	400	705	508	165	411.2	616	88.9	13	20	1 5/8	285	1 3/4	M42	193
18	450	785	565	190	462.3	685.8	101.6	13	20	1 7/8	325	2	M48	258
20	500	855	622	210	514.4	749.3	108	13	20	2	350	2 1/8	M52	317
24	600	1040	749	267	616	901.7	139.7	13	20	2 1/2	440	2 5/8	M64	608

Class 1500 Lap Joint Flange Dimensions

Size in Inch	Size in mm	Outer Diameter	Flange Thick.	Lapped Thick.	Lapped ID	PCD	Lapped Thick.	Lapped Radius	No of Bolts	Bolt Size UNC	RF Stud Length	Hole Size	ISO Stud Size	Weight in kg
		A	B	C	D	E	G
1/2	15	120	38	32	22.9	82.6	22.3	3	4	3/4	110	7/8	M20	1.8
3/4	20	130	44	35	28.2	88.9	25.4	3	4	3/4	115	7/8	M20	2.3
1	25	150	52	41	34.9	101.6	28.6	3	4	7/8	125	1	M24	3.7
1 1/4	32	160	64	41	43.7	111.1	28.6	5	4	7/8	125	1	M24	4.1
1 1/2	40	180	70	44	50	123.8	31.8	6	4	1	140	1 1/8	M27	5.5
2	50	215	105	57	62.5	165.1	38.1	8	8	7/8	145	1	M24	9.8
2 1/2	65	245	124	64	75.4	190.5	41.3	8	8	1	160	1 1/8	M27	16.4
3	80	265	133	73	91.4	203.2	47.7	10	8	1 1/8	180	1 1/4	M30	21.8
4	100	310	162	90	116.8	241.3	54	11	8	1 1/4	195	1 3/8	M33	33
5	125	375	197	105	144.4	292.1	73.1	11	8	1 1/2	250	1 5/8	M39	59
6	150	395	229	119	171.4	317.5	82.6	13	12	1 3/8	260	1 1/2	M36	75
8	200	485	292	143	222.2	393.7	92.1	13	12	1 5/8	290	1 3/4	M42	118
10	250	585	368	178	277.4	482.6	108	13	12	1 7/8	335	2	M48	198
12	300	675	451	219	328.2	571.5	123.9	13	16	2	375	2 1/8	M52	264
14	350	750	495	241	360.2	635	133.4	13	16	2 1/4	405	2 3/8	M56	341
16	400	825	552	260	411.2	704.8	146.1	13	16	2 1/2	445	2 5/8	M64	454
18	450	915	597	276	462.3	774.7	162	13	16	2 3/4	495	2 7/8	M72	590
20	500	985	641	292	514.4	831.8	177.8	13	16	3	540	3 1/8	M76	792
24	600	1170	762	330	616	990.6	203.2	13	16	3 1/2	615	3 5/8	M90	1248

Class 2500 Lap Joint Flange Dimensions

Size in Inch	Size in mm	Outer Diameter	Flange Thick.	Lapped Thick.	Lapped ID	PCD	Lapped Thick.	Lapped Radius	No of Bolts	Bolt Size UNC	RF Stud Length	Hole Size	ISO Stud Size	Weight in kg
		A	B	C	D	E	G
1/2	15	135	43	40	22.9	88.9	30.2	3	4	3/4	120	7/8	M20	3.2
3/4	20	140	51	43	28.2	95.2	31.8	3	4	3/4	125	7/8	M20	3.7
1	25	160	57	48	34.9	108	35	3	4	7/8	140	1	M24	5
1 1/4	32	185	73	52	43.7	130.2	38.1	5	4	1	150	1 1/8	M27	7.5
1 1/2	40	205	79	60	50	146	44.5	6	4	1 1/8	170	1 1/4	M30	10
2	50	235	95	70	62.5	171.4	50.9	8	8	1	180	1 1/8	M27	17.5
2 1/2	65	265	114	79	75.4	196.8	57.2	8	8	1 1/8	195	1 1/4	M30	23
3	80	305	133	92	91.4	228.6	66.7	10	8	1 1/4	220	1 3/8	M33	37.8
4	100	355	165	108	116.8	273	76.2	11	8	1 1/2	255	1 5/8	M39	57
5	125	420	203	130	144.4	323.8	92.1	11	8	1 3/4	300	1 7/8	M45	95
6	150	485	235	152	171.4	368.3	108	13	8	2	345	2 1/8	M52	148
8	200	550	305	178	222.2	438.2	127	13	12	2	380	2 1/8	M52	221
10	250	675	375	229	277.4	539.8	165.1	13	12	2 1/2	490	2 5/8	M64	425
12	300	760	441	254	328.2	619.1	184.2	13	12	2 3/4	540	2 7/8	M72	500

Disclaimer –  Please check with ASME B16.5 Before using.