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Ring Joint Facings for Class 150 ASME B16.5 Flanges

1. Technical drawings of ring joint facings for Class 150 ASME B16.5 Flanges.

2. Dimensions of ring joint facings for Class 150 Flange Joints and Groove.

NPS	Groove Number	P inch mm	E inch mm	F inch mm	R inch mm	K inch mm	S inch mm
1"	R15	1.875 47.63	0.250 6.35	0.344 8.74	0.03 0.8	2.5 63.5	0.16 4
1-1/4"	R17	2.250 57.15	0.250 6.35	0.344 8.74	0.03 0.8	2.88 73.0	0.16 4
1-1/2"	R19	2.562 65.07	0.250 6.35	0.344 8.74	0.03 0.8	3.25 82.5	0.16 4
2"	R22	3.250 82.55	0.250 6.35	0.344 8.74	0.03 0.8	4.00 102	0.16 4
2-1/2"	R25	4.000 101.6	0.250 6.35	0.344 8.74	0.03 0.8	4.75 121	0.16 4
3"	R29	4.500 114.3	0.250 6.35	0.344 8.74	0.03 0.8	5.25 133	0.16 4
3-1/2"	R33	5.188 131.78	0.250 6.35	0.344 8.74	0.03 0.8	6.06 154	0.16 4
4"	R36	5.875 149.23	0.250 6.35	0.344 8.74	0.03 0.8	6.75 171	0.16 4
5"	R40	6.750 171.45	0.250 6.35	0.344 8.74	0.03 0.8	7.62 194	0.16 4
6"	R43	7.625 193.68	0.250 6.35	0.344 8.74	0.03 0.8	8.62 219	0.16 4
8"	R48	9.750 247.65	0.250 6.35	0.344 8.74	0.03 0.8	10.75 273	0.16 4
10"	R52	12.000 304.80	0.250 6.35	0.344 8.74	0.03 0.8	13.00 330	0.16 4
12"	R56	15.000 381.00	0.250 6.35	0.344 8.74	0.03 0.8	16.00 406	0.16 4
14"	R59	15.625 396.88	0.250 6.35	0.344 8.74	0.03 0.8	16.75 425	0.12 3
16"	R64	17.875 454.03	0.250 6.35	0.344 8.74	0.03 0.8	19.00 483	0.12 3
18"	R68	20.375 517.53	0.250 6.35	0.344 8.74	0.03 0.8	21.50 546	0.12 3
20"	R72	22.000 558.80	0.250 6.35	0.344 8.74	0.03 0.8	23.50 597	0.12 3
24"	R76	26.500 673.10	0.250 6.35	0.344 8.74	0.03 0.8	28.00 711	0.12 3

1. NPS denotes nominal pipe size, P – pitch diameter, E – depth of the groove & height of the raised portion, F – top width of the groove, R – radius at bottom, K – diameter of raised portion, S – approximate distance between flanges. The 150# RTJ flange facings can be applied to various flange types including welding neck flange class 150, slip on flange 150#, Blind flange 150lb, etc.

2. All dimensions are provided in mm and inch unit. The depth of the groove, E, shall be furnished with the same dimension as the height of the raised portion. The groove number of ring joint facings for class 150 shall match the type R ring gaskets manufactured to ASME B16.20.

Ring Joint Facings for ASME B16.5 Flanges Classified by Classes
Class 150	Class 300	Class 400	Class 600	Class 900	Class 1500	Class 2500

Flange Bolting for Class 150 ASME B16.5 Flanges

1. Technical drawings of flange bolting for Class 150 ASME B16.5 flanges.

machine bolt with nuts and stud bolt with nuts for class 150 flanges

flange bolting for class 150 - drilling templates — Drilling templates for asme b16.5 class 150 flanges

2. Dimension of flange bolting for Class 150 ASME B16.5 flanges.

NPS	O inch mm	W inch mm	m inch	n	d inch	L1 inch mm	L2 inch mm	L3 inch mm
1/2"	3.50 90	2.38 60.3	5/8	4	1/2	2.25 55	-	2.00 50
3/4"	3.88 100	2.75 69.6	5/8	4	1/2	2.50 65	-	2.00 50
1"	4.25 110	3.12 79.4	5/8	4	1/2	2.50 65	3.00 75	2.25 55
1 1/4"	4.62 115	3.50 88.9	5/8	4	1/2	2.75 70	3.25 85	2.25 55
1 1/2"	5.00 125	3.88 98.4	5/8	4	1/2	2.75 70	3.25 85	2.50 65
2"	6.00 150	4.75 120.7	3/4	4	5/8	3.25 85	3.75 95	2.75 70
2 1/2"	7.00 180	5.50 139.7	3/4	4	5/8	3.50 90	4.00 100	3.00 75
3"	7.50 190	6.00 152.4	3/4	4	5/8	3.50 90	4.00 100	3.00 75
3 1/2"	8.50 215	7.00 177.8	3/4	8	5/8	3.50 90	4.00 100	3.00 75
4"	9.00 230	7.50 190.5	3/4	8	5/8	3.50 90	4.00 100	3.00 75
5"	10.00 255	8.50 215.9	7/8	8	3/4	3.75 95	4.25 110	3.25 85
6"	11.00 280	9.50 241.3	7/8	8	3/4	4.00 100	4.50 115	3.25 85
8"	13.50 345	11.75 298.5	7/8	8	3/4	4.25 110	4.75 120	3.50 90
10"	16.00 405	14.25 362.0	1	12	7/8	4.50 115	5.00 125	4.00 100
12"	19.00 485	17.00 431.8	1	12	7/8	4.75 120	5.25 135	4.00 100
14"	21.00 535	18.75 476.3	1 1/8	12	1	5.25 135	5.75 145	4.50 115
16"	23.5 595	21.25 539.8	1 1/8	16	1	5.25 135	5.75 145	4.50 115
18"	25.00 635	22.75 577.9	1 1/4	16	1 1/8	5.75 145	6.25 160	5.00 125
20"	27.50 700	25.00 635.0	1 1/4	20	1 1/8	6.25 160	6.75 170	5.50 140
24"	32.00 815	29.50 749.3	1 3/8	20	1 1/4	6.75 170	7.25 185	6.00 150

1. NPS refers to Nominal Pipe Size, O – outside diameter of flange, W – Diameter of bolt circle, m – Diameter of bolt holes, n – number of bolts, d – diameter of bolts, L1 – length of stud bolts for 2 mm raised face, L2 – length of stud bolts for ring joint face, L3 – length of machine bolts for raised face.

2. The bolting of ASME B16.5 class 150 flanges can be furnished as machine bolt with nuts or stud bolts with nuts. Machine bolts shall be only used for flanges with raised face while stud bolts can be used for flanges with either raised face or ring joint face. All dimensions are provided in mm and inch units.

3. Contact our sales team for a quick quote: info@metalsflange.com

ASME B16.5 Flange Bolting Specification by Classes
Class 150	Class 300	Class 400	Class 600	Class 900	Class 1500	Class 2500

ASME B16.5 Weld Neck Flanges 400LB

Technical drawing of ASME B16.5 weld neck flanges 400LB.

Weld Neck Flanges 400LB RF — The typical drawing of weld neck flanges 400LB with raised face according to ASME B16.5.

Dimension and weight specifications of ASME B16.5 Weld Neck flanges 400LB.

NPS	D inch mm	K inch mm	G inch mm	B inch mm	A inch mm	X inch mm	n	L inch	t inch mm	H inch mm	Wt. lbs kgs
1/2"	3.75 95	2.62 66.7	1.38 34.9	-	0.84 21.3	1.50 38	4	5/8	0.56 14.3	2.06 52	1.90 0.87
3/4"	4.62 115	3.25 82.6	1.69 42.9	-	1.05 26.7	1.88 48	4	3/4	0.62 15.9	2.25 57	3.20 1.45
1"	4.88 125	3.50 88.9	2.00 50.8	-	1.32 33.4	2.12 54	4	3/4	0.69 17.5	2.44 62	3.90 1.76
1-1/4"	5.25 135	3.88 98.4	2.50 63.5	-	1.66 42.2	2.50 64	4	3/4	0.81 20.7	2.62 67	5.50 2.49
1-1/2"	6.12 155	4.50 114.3	2.88 73.0	-	1.90 48.3	2.75 70	4	7/8	0.88 22.3	2.75 70	7.70 3.49
2"	6.50 165	5.00 127.0	3.62 92.1	-	2.39 60.3	3.31 84	8	3/4	1.00 25.4	2.88 73	9.60 4.36
2-1/2"	7.50 190	5.88 149.2	4.12 104.8	-	2.88 73.0	3.94 100	8	7/8	1.12 28.6	3.12 79	14.2 6.43
3"	8.25 210	6.62 168.3	5.00 127.0	-	3.50 88.9	4.62 117	8	7/8	1.25 31.8	3.25 83	18.8 8.53
3-1/2"	9.00 230	7.25 184.2	5.50 139.7	-	4.00 101.6	5.25 133	8	1	1.38 35.0	3.38 86	23.6 10.7
4"	10.00 255	7.88 200.0	6.19 157.2	-	4.50 114.3	5.75 146	8	1	1.38 35.0	3.50 89	28.2 12.8
5"	11.00 280	9.25 235.0	7.31 185.7	-	5.56 141.3	7.00 178	8	1	1.50 38.1	4.00 102	37.2 16.9
6"	12.50 320	10.62 269.9	8.50 215.9	-	6.63 168.3	8.12 206	12	1	1.62 41.3	4.06 103	48.5 22.0
8"	15.00 380	13.00 330.0	10.62 269.9	-	8.63 219.1	10.25 260	12	1-1/8	1.88 47.7	4.62 117	76.4 34.7
10"	17.50 445	15.25 387.4	12.75 323.8	-	10.75 273.0	12.62 321	16	1-1/4	2.12 54.0	4.88 124	107 48.5
12“	20.50 520	17.75 450.8	15.00 381.0	-	12.75 323.8	14.75 375	16	1-3/8	2.25 57.2	5.38 137	153 69.6
14”	23.00 585	20.25 514.4	16.25 412.8	-	14.00 355.6	16.75 425	20	1-3/8	2.38 60.4	5.88 149	210 95.5
16“	25.50 650	22.50 571.5	18.50 469.9	-	16.00 406.4	19.00 483	20	1-1/2	2.50 63.5	6.00 152	260 118
18”	28.00 710	24.75 628.6	21.00 533.4	-	18.00 457.0	21.00 533	24	1-1/2	2.62 66.7	6.50 165	319 145
20“	30.50 775	27.00 685.8	23.00 584.2	-	20.00 508.0	23.12 587	24	1-5/8	2.75 69.9	6.62 168	383 174
24”	36.00 915	32.00 812.8	27.25 692.2	-	24.00 610.0	27.62 702	24	1-7/8	3.00 76.2	6.88 175	553 251

(1) 400LB refers to Class 400 which is one of the pressure ratings stipulated by ASME B16.5. For dimensional denotation of D, K, G, t, H, A, X, n and L, please reference WN flanges Class 150. The welding end and flange facing(usually RF or RTJ) shall be furnished in accordance with ASME B16.5.

(2) The raised face of weld neck flanges 400LB shall be furnished with a height of 7 mm. All dimensions are provided in both metric and imperial units except for the bolt hole dimensions. Each value of the two systems shall be used separately. The bore diameter B shall be specified by the purchaser. Sizes from NPS 1/2 to NPS 3-1/2 has exactly the same dimensions as that of weld neck flanges 600LB (Class 600).

Weight Calculation of Weld Neck Flanges

Weld Neck flanges, also know as “WN flanges” or “Welding Neck flanges”, are widely used in oil and gas industry, steam piping and offshore platforms. Sometimes, it is necessary to know the weight of a weld neck flange in piping design. Instead of querying the experimental data from flange manufacturers, theoretical weight can be calculated directly. The weight calculation of weld neck flanges is based on the geometrical or mathematical modeling of the flange.

The typical drawing of weld neck flanges

Mathematical Modeling for weight calculation of weld neck flanges

The typical drawing is for weld neck flanges in accordance with ASME B16.5. The welding end is furnished with beveling for wall thickness from 5 mm to 22 mm (inclusive). And the flange has raised face (RF).

All the dimensions are covered by the standard specification: H – the overall length through hub of weld neck flanges; T – minimum thickness of the flange; t – the height of raised face(2mm for Class 150 and 300, 7mm for Class 400 600, 900, 1500 and 2500); D – outside diameter of the flange; K – diameter of bolt circle; G – outside diameter of the raised face; B – bore diameter of weld neck flanges which is in accordance with ASME B36.10; A – hub diameter at the beginning of chamfer of welding neck flanges; X- root diameter of the hub; n – number of bolts; L – diameter of bolt holes.

Mathematical modeling for weight calculation of weld neck flanges

As illustrated in above drawing, geometrically the weld neck flange can be divided into 4 parts.

Part I can be treated as a short length of pipe. According to ASME B16.5, the straight length is furnished in 10 mm. Hence the weight of Part I can be calculated by using the weight-calculation formula of pipe:
W₁ = 0.0246615 * (A – T_k) * T_k * 0.01 T_k– wall thickness of the mating pipe.

Part II can be treated as a truncated cone deducted by a cylinder. Its weight can be calculated as:
W₂ = {1/3 * π * (H – T – t – 0.01) * [(X/2)² + (A/2)² + X*A/4)] – 1/4 * π * B² * (H – T – t – 0.01)} * ρ

Part III is a cylinder deducted by several small cylinders(bolt holes and bore):
W₃ = 1/4 * π * (D² – B² – n*L²) * T * ρ

Part IV, the raised face, can be treated as a cylinder deducted by another cylinder(bore):
W₄ = 1/4 * π * (G² – B²) * t * ρ

The total weight of the weld neck flange is W = W₁ + W₂ + W₃ + W₄

ASME B16.5 Weld Neck Flanges 300LB

Technical drawing of ASME B16.5 weld neck flanges 300LB.

Weld Neck Flanges 300LB RF — The typical drawing for WN RF flanges Class 300 according to ASME B16.5.

Dimension and weight specifications of ASME B16.5 Weld Neck flanges 300LB.

NPS	D inch mm	K inch mm	G inch mm	B inch mm	A inch mm	X inch mm	n	L inch	t inch mm	H inch mm	Wt. lbs kgs
1/2"	3.75 95	2.62 66.7	1.38 34.9	0.62 15.8	0.84 21.3	1.50 38	4	5/8	0.50 12.7	2.00 51	1.70 0.75
3/4"	4.62 115	3.25 82.6	1.69 42.9	0.82 20.9	1.05 26.7	1.88 48	4	3/4	0.56 14.3	2.19 56	2.82 1.27
1"	4.88 125	3.50 88.9	2.00 50.8	1.05 26.6	1.32 33.4	2.12 54	4	3/4	0.62 15.9	2.38 60	3.50 1.52
1-1/4"	5.25 135	3.88 98.4	2.50 63.5	1.38 35.1	1.66 42.2	2.50 64	4	3/4	0.69 17.5	2.50 64	4.50 2.03
1-1/2"	6.12 155	4.50 114.3	2.88 73.0	1.61 40.9	1.90 48.3	2.75 70	4	7/8	0.75 19.1	2.63 67	6.40 2.89
2"	6.50 165	5.00 127.0	3.62 92.1	2.07 52.5	2.38 60.3	3.31 84	8	3/4	0.81 20.7	2.69 68	7.50 3.40
2-1/2"	7.50 190	5.88 149.2	4.12 104.8	2.47 62.7	2.88 73.0	3.94 100	8	7/8	0.94 23.9	2.94 75	11.40 5.17
3“	8.25 210	6.62 168.3	5.00 127.0	3.07 77.9	3.50 88.9	4.62 117	8	7/8	1.06 27.0	3.06 78	15.3 6.93
3-1/2”	9.00 230	7.25 184.2	5.50 139.7	3.55 90.1	4.00 101.6	5.25 133	8	7/8	1.12 28.6	3.13 79	19.1 8.67
4“	10.00 255	7.88 200	6.19 157.2	4.03 102.3	4.50 114.3	5.75 146	8	7/8	1.19 30.2	3.32 84	24.7 11.2
5”	11.00 280	9.25 235.0	7.31 185.7	5.05 128.2	5.56 141.3	7.00 178	8	7/8	1.31 33.4	3.82 97	33.3 15.1
6“	12.50 320	10.62 269.9	8.50 215.9	6.07 154.1	6.63 168.3	8.12 206	12	7/8	1.38 35.0	3.82 97	42.4 19.1
8”	15.00 380	13.00 330.2	10.62 269.9	7.98 202.7	8.63 219.1	10.25 260	12	1	1.56 39.7	4.32 110	65.9 29.9
10“	17.50 445	15.25 387.4	12.75 323.8	10.02 254.6	10.75 273.0	12.62 321	16	1-1/8	1.81 46.1	4.56 116	94.1 42.7
12”	20.50 520	17.75 450.8	15.00 381.0	12.00 304.8	12.75 323.8	14.75 375	16	1-1/4	1.94 49.3	5.06 129	136.2 61.9
14“	23.00 585	20.25 514.4	16.25 412.8	-	14.00 355.6	16.75 425	20	1-1/4	2.06 52.4	5.56 141	189 85.8
16”	25.50 650	22.50 571.5	18.50 469.9	-	16.00 406.4	19.00 483	20	1-3/8	2.19 55.6	5.69 144	234 106
18“	28.00 710	24.75 628.6	21.00 533.4	-	18.00 457.0	21.00 533	24	1-3/8	2.31 58.8	6.19 157	289 131
20”	30.50 775	27.00 685.8	23.00 584.2	-	20.00 508.0	23.12 587	24	1-3/8	2.44 62.0	6.32 160	348 158
24“	36.00 915	32.00 812.8	27.25 692.2	-	24.00 610.0	27.62 702	24	1-5/8	2.69 68.3	6.56 167	507 230

(1) 300LB refers to Class 300 which is one of the pressure ratings stipulated by ASME B16.5. Dimensions D, B, t and H refer to the basic flange dimensions: D – outside diameter of flange, B – bore diameter of weld neck flange, t – minimum thickness of flange, H – length through hub of weld neck flange. n, L and K refer to the bolting drilling dimensions of flange: n – number of bolts, L – diameter of bolt holes, K – diameter of bolt circle. G denotes the outside diameter of raised face. A and X are dimensions associated with the hub: A – diameter at the top of hub, X – diameter at the root of hub. A is the same as the nominal outside diameter of the pipe connected to the flange.

(2) Usually two types of welding ends can be furnished according to different wall thickness of the pipe. The bore diameters of weld neck flanges 300LB correspond to the inside diameters of pipe as given in ASME B36.10 for standard(STD) wall pipe. Thickness of standard wall is the same as SCH40 in sizes 10″ and smaller. These bore sizes are furnished unless otherwise specified by the purchaser. Besides, bore diameters of 14″ and larger shall be specified by the purchaser. Ring joint facing (RTJ) is also available upon request. All tolerances shall be in accordance with ASME B16.5.

(3) The raised-face length(2 mm) of Weld neck flanges 300LB is the same as that of weld neck flanges 150LB. All dimensions are provided in both metric and imperial units except for the bolt hole dimensions. Each value of the two systems shall be used separately.

ASME B16.5 Weld Neck Flanges 150LB

Technical drawing of ASME B16.5 weld neck flanges 150LB.

Dimension and weight specifications of ASME B16.5 Weld Neck flanges 150LB.

NPS	D inch mm	K inch mm	G inch mm	B inch mm	A inch mm	X inch mm	n	L inch	t inch mm	H inch mm	Wt. lbs kgs
1/2"	3.50 90	2.38 60.3	1.38 34.9	0.62 15.8	0.84 21.3	1.19 30	4	5/8	0.38 9.6	1.81 46	1.10 0.48
3/4"	3.88 100	2.75 69.9	1.69 42.9	0.82 20.9	1.05 26.7	1.50 38	4	5/8	0.44 11.2	2.00 51	1.62 0.71
1"	4.25 110	3.12 79.4	2.00 50.8	1.05 26.6	1.32 33.4	1.94 49	4	5/8	0.50 12.7	2.12 54	2.21 1.02
1-1/4"	4.62 115	3.50 88.9	2.50 63.5	1.38 35.1	1.66 42.2	2.31 59	4	5/8	0.56 14.3	2.19 56	2.90 1.33
1-1/2"	5.00 125	3.88 98.4	2.88 73.0	1.61 40.9	1.90 48.3	2.56 65	4	5/8	0.62 15.9	2.38 60	3.82 1.75
2"	6.00 150	4.75 120.7	3.62 92.1	2.07 52.5	2.38 60.3	3.06 78	4	3/4	0.69 17.5	2.44 62	5.70 2.58
2-1/2"	7.00 180	5.50 139.7	4.12 104.8	2.47 62.7	2.88 73.0	3.56 90	4	3/4	0.81 20.7	2.69 68	9.11 4.13
3"	7.50 190	6.00 152.4	5.00 127.0	3.07 77.9	3.50 88.9	4.25 108	4	3/4	0.88 22.3	2.69 68	10.80 4.92
3-1/2"	8.50 215	7.00 177.8	5.50 139.7	3.55 90.1	4.00 101.6	4.81 122	8	3/4	0.88 22.3	2.75 70	13.40 6.08
4"	9.00 230	7.50 190.5	6.19 157.2	4.03 102.3	4.50 114.3	5.31 135	8	3/4	0.88 22.3	2.94 75	15.10 6.84
5"	10.00 255	8.50 215.9	7.31 185.7	5.05 128.2	5.56 141.3	6.44 164	8	7/8	0.88 22.3	3.44 87	18.90 8.56
6"	11.00 280	9.50 241.3	8.50 215.9	6.07 154.1	6.63 168.3	7.56 192	8	7/8	0.94 23.9	3.44 87	23.30 10.60
8"	13.50 345	11.75 298.5	10.62 269.9	7.98 202.7	8.63 219.1	9.69 246	8	7/8	1.06 27.0	3.94 100	38.80 17.70
10"	16.00 405	14.25 362.0	12.75 323.8	10.02 254.6	10.75 273.0	12.00 305	12	1	1.12 28.6	3.94 100	53.00 24.00
12"	19.00 485	17.00 431.8	15.00 381.0	12.00 304.8	12.75 323.8	14.38 365	12	1	1.19 30.2	4.44 113	80.40 36.50
14"	21.00 535	18.75 476.3	16.25 412.8	-	14.00 355.6	15.75 400	12	1-1/8	1.31 33.4	4.94 125	107.0 48.40
16"	23.50 595	21.25 539.8	18.50 469.9	-	16.00 406.4	18.00 457	16	1-1/8	1.38 35.0	4.94 125	134.0 60.60
18"	25.00 635	22.75 577.9	21.00 533.4	-	18.00 457.0	19.88 505	16	1-1/4	1.50 38.1	5.44 138	151.2 68.4
20"	27.50 700	25.00 635.0	23.00 584.2	-	20.00 508.0	22.00 559	20	1-1/4	1.62 41.3	5.64 143	187.00 84.82
24"	32.00 815	29.50 749.3	27.25 692.2	-	24.00 610.0	26.12 663	20	1-3/8	1.81 46.1	5.94 151	253.0 115.0

(1) 150LB refers to Class 150 which is one of the pressure ratings stipulated by ASME B16.5. Dimensions D, B, t and H refer to the basic flange dimensions: D – outside diameter of flange, B – bore diameter of weld neck flange, t – minimum thickness of flange, H – length through hub of weld neck flange. n, L and K refer to the bolting drilling dimensions of flange: n – number of bolts, L – diameter of bolt holes, K – diameter of bolt circle. G denotes the outside diameter of raised face. A and X are dimensions associated with the hub: A – diameter at the top of hub, X – diameter at the root of hub. A is the same as the nominal outside diameter of the pipe connected to the flange.

(2) Usually two types of welding ends can be furnished according to different wall thickness of the pipe. The bore diameters of weld neck flanges 150LB correspond to the inside diameters of pipe as given in ASME B36.10 for standard(STD) wall pipe. Thickness of standard wall is the same as SCH40 in sizes 10″ and smaller. These bore sizes are furnished unless otherwise specified by the purchaser. Besides, bore diameters of 14″ and larger shall be specified by the purchaser. Ring joint facing (RTJ) is also available upon request. All tolerances shall be in accordance with ASME B16.5.

(3) All dimensions are provided in both metric and imperial units except for the bolt hole dimensions. Each value of the two systems shall be used separately.

Welding Ends for Weld Neck Flanges

According to ASME B16.5 and ASME B16.25, welding neck flanges can be furnished with two types of welding ends which are illustrated in below figures:

Welding ends of weld neck flanges thin — The welding ends of weld neck flanges for wall thickness 5 mm < t ≤ 22 mm.

welding ends of wn flange thick — The welding end of weld neck flanges for wall thickness t > 22mm.

Dimension A denotes nominal outside diameter of the pipe while B denotes nominal inside diameter of the pipe. The t and X respectively represent nominal wall thickness and the diameter of hub of the weld neck flange.

When the thickness of the hub at the bevel is greater than that of the pipe to which the welding neck flange is joined and the additional thickness is provided on the outside diameter, a taper weld having a slope not exceeding 1 to 3 maybe used, or alternatively, the greater outside diameter may be tapered at the same maximum slope or less, from a point on the welding bevel equal to the outside diameter of the mating pipe. Similarly, when the greater thickness is provided on the inside of the flange, it shall be taper-bored from the welding end at a slope not exceeding 1/3. When ASME B16.5 flanges are intended for services with light wall, higher strength pipe, the thickness of the hub at the bevel may be greater than that of the pipe to which the flange is joined. Under these conditions, a single taper hub may be provided. The additional thickness may be provided on either inside or outside or partially on each side, but the total additional thickness shall not exceed 1.5 times the nominal wall thickness of intended mating pipe.

Besides, the hub transition from the A diameter to the X diameter shall fall within the maximum and minimum envelope outlined by the 1:3 max slope and solid line. The 6-mm length is the minimum dimension applies only to the solid line configuration.

ASTM A182 F5 Flanges

ASTM A182 F5 flanges are forged flanges manufactured from a chromium-molybdenum low alloy steel know as 5Cr-0.5Mo with a UNS designation of K41545. They are widely utilized in pressure high-temperature services such as oil refineries, chemical and petrochemical industries, power plant piping, heat exchangers, and various pressure vessels.

Chemical composition of ASTM A182 Gr. F5

C	Mn	P	S	Si	Ni	Cr	Mo
0.15 max	0.30~0.60	0.030 max	0.030 max	0.50 max	0.50 max	4.0~6.0	0.44~0.65

The chromium (Cr) added in F5 not only increases resistance to abrasion and corrosion but also improves resistance to high-temperature hydrogen attack and graphitization. The molybdenum (Mo) content is acting as a grain refiner which enhances creep resistance and high-temperature strength. It also improves resistance to pitting corrosion in many environments. The creep strength of chromium-molybdenum low alloy is derived mainly from two sources: solid-solution strengthening of the matrix ferrite by carbon, molybdenum and chromium as well as precipitation hardening by carbides. As a result, the creep strength (for 1% elongation in 10⁵ hours) of A182 Grade F5 may reach approx. 170 MPa at 450 °C.

Mechanical requirements and heat treatment.

Tensile Strength, min, ksi [MPa]	Yield Strength, min, kis [MPa]	Elongation, min, %	Reduction of Area, min, %	Brinell Hardness, HBW
70 [485]	40 [275]	20	35	143~217

According to ASME B16.5, pipe flanges manufactured from A812 Gr. F5 material shall be normalized and tempered at a temperature higher than 955 °C (1750 °F). The material is permissible but not recommended for prolonged use above 590 °C.

Pressure-Temperature ratings for ASTM A182 F5 flanges.

Temp. °C	Class 150	Class 300	Class 400	Class 600	Class 900	Class 1500	Class 2500
-29~38	19.8	51.7	68.9	103.4	155.1	258.6	430.9
50	19.5	51.5	68.7	103.0	154.5	257.5	429.2
100	17.7	50.4	67.3	100.9	151.3	252.2	420.4
150	15.8	48.2	64.2	96.4	144.5	240.9	401.5
200	13.8	46.3	61.7	92.5	138.8	231.3	385.6
250	12.1	44.8	59.8	89.6	134.5	224.1	373.5
300	10.2	42.9	57.0	85.7	128.6	214.4	357.1
325	9.3	41.4	55.0	82.6	124.0	206.6	344.3
350	8.4	40.3	53.6	80.4	120.7	201.1	335.3
375	7.4	38.9	51.6	77.6	116.5	194.1	323.2
400	6.5	36.5	48.9	73.3	109.8	183.1	304.9
425	5.5	35.2	46.5	70.0	105.1	175.1	291.6
450	4.6	33.7	45.1	67.7	101.4	169.0	281.8
475	3.7	27.9	37.1	55.7	83.6	139.3	232.1
500	2.8	21.4	28.5	42.8	64.1	106.9	178.2
538	1.4	13.7	18.3	27.4	41.1	68.6	114.3
550	-	12.0	16.1	24.1	36.1	60.2	100.4
575	-	8.8	11.7	17.6	26.4	44.0	73.4
600	-	6.1	8.1	12.1	18.2	30.3	50.4
625	-	4.0	5.3	8.0	12.0	20.0	33.3
650	-	2.4	3.2	4.7	7.1	11.8	19.7

ASME B16.5 Flange facing and Facing Finish

Various types of flange facing.

According to ASME B16.5, there are several types of end flange facing which shall be calculated and selected carefully to ensure a leak-free seal.

End Flange Facing 01 — End Flange Facings 01

End Flange Facing 02 — End Flange Facings 02

Figures A and B show the most common flange facing of raised face. 2 mm raised face is regularly furnished on Class 150 and Class 300 while 7 mm raised face is furnished on Class 400, Class 600, Class 900, Class 1500 and Class 2500. Figures C, D, E, F, G, H respectively illustrate the facing type of large or small male face, large or small female face, small male face(on end of pipe), small female face(on end of pipe), large or small tongue face, and large or small groove face. Figure I is the typical drawing of ring joint face which is also a prevalent flange connection requiring a metallic ring either in oval or octagonal shape. In the case of flanges having raised face, tongue, or male face, the minimum flange thickness t_f, shall be provided, and then the raised face, tongue or male face shall be added thereto. For flanges that have a ring joint, groove, or female face, the minimum flange thickness t_f shall first be provided and then sufficient thickness added thereto so that the bottom of the ring joint groove, or the contact face of the groove or female face, is in the same plane as the flange edge of a full thickness flange.

Flat faces are usually used in cast iron flanges such as AWWA flanges in water supply service. However, lapped joint flanges shall be furnished with flat face (FF) as illustrated in figure G and K. The stub ends can be provided with raised face or ring joint face in similar function.

Surface finishes of flange facing.

The raised face or flat face shall be furnished with a serrated concentric or serrated spiral finish having a resultant surface roughness from 3.2μm to 6.3μm. The cutting tool employed should have an approximate 1.5 mm or larger radius, and there should be from 1.8 grooves/ mm through 2.2 grooves/ mm. The side wall surface roughness of the ring-joint gasket groove shall not exceed 1.6μm. For groove, tongue and small male and female, the gasket contact surface finish shall not exceed 3.2μm roughness.

Incoloy 800 Flanges (ASTM B564 UNS N08800)

1. General Introduction

Incoloy 800 flanges (pipe flanges) refer to forged flanges manufactured to ASTM B564 according to the dimensional standards of ASME B16.5. Incoloy 800, also known as Alloy 800 or UNS N08800, is an iron-nickel-chromium alloy with good creep & stress-rupture strength and excellent resistance to oxidation, sulfurization and carburization in high-temperature services. It also resists corrosion by many aqueous environments. The forged Incoloy 800 flanges can be used in applications with temperatures up to 816°C while maintaining a stable, austenitic structure during prolonged exposure to high temperatures. The material is widely utilized in processing piping, heat exchangers, heating element sheathing, petrochemical pipeline(especially for heavy oil) and nuclear power plant, etc.

Incoloy 800 Flanges WN RTJ — Incoloy 800 weld neck flange, RTJ, API 6A.

2. Pressure-Temperature ratings for Incoloy 800 flanges

Temp. °C	Class 150	Class 300	Class 400	Class 600	Class 900	Class 1500	Class 2500
-29~38	19.0	49.6	66.2	99.3	148.9	248.2	413.7
50	18.7	48.8	65.1	97.6	146.4	244.0	406.7
100	17.5	45.6	60.8	91.2	136.9	228.1	380.1
150	15.8	44.0	58.7	88.0	132.0	219.9	366.6
200	13.8	42.8	57.1	85.6	128.4	214.0	356.7
250	12.1	41.7	55.7	83.5	125.2	208.7	347.9
300	10.2	40.8	54.4	81.6	122.5	204.1	340.2
325	9.3	40.3	53.8	80.6	120.9	201.6	336.0
350	8.4	39.8	53.0	79.5	119.3	198.8	331.3
375	7.4	38.9	51.6	77.6	116.5	194.1	323.2
400	6.5	36.5	48.9	73.3	109.8	183.1	304.9
425	5.5	35.2	46.5	70.0	105.1	175.1	291.6
450	4.6	33.7	45.1	67.7	101.4	169.0	281.8
475	3.7	31.7	42.3	63.4	95.1	158.2	263.9
500	2.8	28.2	37.6	56.5	84.7	140.9	235.0
538	1.4	25.2	33.4	50.0	75.2	125.5	208.9
550	-	25.0	33.3	49.8	74.8	124.9	208.0
575	-	24.0	31.9	47.9	71.8	119.7	199.5
600	-	21.6	28.6	42.9	64.2	107.0	178.5
625	-	18.3	24.3	36.6	54.9	91.2	152.0
650	-	14.1	18.9	28.1	42.5	70.7	117.7
675	-	10.3	13.7	20.5	30.8	51.3	85.6
700	-	5.6	7.4	11.1	16.7	27.8	46.3
725	-	4.0	5.4	8.1	12.1	20.1	33.6
750	-	3.0	4.0	6.1	9.1	15.1	25.2
775	-	2.5	3.3	4.9	7.4	12.4	20.6
800	-	2.2	2.9	4.3	6.5	10.8	18.0
816	-	1.9	2.5	3.8	5.7	9.5	15.8

*All the forged Alloy 800 flanges shall be annealed.

3. Chemical composition requirements for Incoloy 800 (UNS N08800).

Chemical Composition of Incoloy 800

Element	Content, %
Nickel (Ni)	30.0~35.0
Copper (Cu)	0.75 max
Iron (Fe)	39.5 min
Manganese (Mn)	1.5 max
Carbon (C)	0.10 max
Silicon (Si)	1.0 max
Sulfur (S)	0.015 max
Chromium (Cr)	19.0~23.0
Aluminum (Al)	0.15~0.60
Titanium (Ti)	0.15~0.60

*Chromium additions improve sulfidation resistance while aluminum and titanium allow strengthening through precipitation hardening (age hardening). Nickel content not only improves the fatigue strength and high-temperature performance(especially in reducing environments) but also inherently resists to reducing corrosion, both acid and alkali. Thus, Incoloy 800 has better resistance to reducing corrosion than common austenitic stainless steels.

4. Mechanical requirements for Incoloy 800 forgings.

Mechanical Properties of Incoloy 800

Tensile Strength, min ksi (MPa)	Yield Strength, min ksi (MPa)	Elongation min. %
75 (517)	30 (207)	30

*The forgings shall take ultrasonic test or liquid penetration inspection. Liquid penetration inspection is not applicable to forgings with hot finished surface.