How to get high quality orifice flanges?

19 Jan

How to get high quality orifice flanges?

2018-01-19

What are Orifice Flanges?

Orifice Flanges are used with orifice meters for the purpose of measuring the flow rate of either liquids or gases in the respective pipeline. Pairs of pressure “Tappings”, mostly on 2 sides, directly opposite each other, are machined into the orifice flange. This makes separate orifice carriers or tappings in the pipe wall unnecessary.

Table of Contents hide
1 What are Orifice Flanges?
2 DATASHEETS AND DIMENSIONAL INFORMATION
2.1 WN ORIFICE FLANGE / RF
2.1.1 CLASS 300 WELD NECK ORIFICE FLANGE RF
2.2 FLANGE – ORIFICE, WELD NECK, ANSI CLASS 400, B16.36 (IN)
2.3 CLASS 600 WELD NECK ORIFICE FLANGE RF
2.3.1 (ASME B16.5 ASTM A182 F51 ORIFICE FLANGE RF 300LB 10 INCH)
2.4 CLASS 900 WELD NECK ORIFICE FLANGE RF
2.5 CLASS 1500 WELD NECK ORIFICE FLANGE RF
2.6 CLASS 2500 WELD NECK ORIFICE FLANGE RF
2.7 WN ORIFICE FLANGE / RTJ
2.8 CLASS 600 WELD NECK ORIFICE RTJ
2.9 CLASS 900 WELD NECK ORIFICE RTJ
2.10 CLASS 1500 WELD NECK ORIFICE RTJ
2.11 CLASS 2500 WELD NECK ORIFICE RTJ
3 Drawing of Orifice Flanges
3.1 Slip-on Orifice Run
3.2 Orifice flange union
4 An Orifice Flange
5 Installing the orifice plate flange
5.1 Orifice Flange/Plate Sealing Finishes
5.1.1 Orifice Weld Neck Flanges
6 Standards, Dimensions & Weight
7 Tolerances and ratings follow ANSI B16.5 except for the following:
8 Advantages of Orifice Flanges:

Orifice Flanges generally come with either Raised Faces or RTJ (Ring Type Joint) facings. They are, for all intensive purposes, the same as weld neck and slip on flanges with extra machining.

The image on the right shows a set Orifice Flanges, where a Orifice Plate is mounted and a jack screw is machined. This jack screw is used to facilitate separating the flanges for inspection or replacement of the Orifice Plate and gaskets.

The range of orifice flanges covers all standard sizes and ranges, and all common flange materials. Flanges are available in Welding Neck, Slip On, and Threaded form, and are typically supplied with two 1/2″ NPT tappings in each flange.

ASME B16.36 covers Dimensions and dimensional tolerances from orifice flanges (similar to those covered in ASME B16.5) that have orifice pressure differential connections. Coverage is limited to the following flanges:

  • WELDING NECK CLASSES 300, 400, 600, 900, 1500, 2500
  • SLIP ON CLASS 300
  • THREADED CLASS 300

DATASHEETS AND DIMENSIONAL INFORMATION

Orifice Flange manufacturer Yaang supplies Orifice Flanges, Plate Flanges

WN ORIFICE FLANGE / RF

GENERAL COMMENTS:

  • Dimensions are in millimeters (excluding bolts and bolt holes).

  • Different NPT sizes than 1/2 may be supplied

  • Bolt lengths for RF flanges include allowance for orifice and gasket thickness of 6 mm (0.25 in.) for NPS 1 to NPS 12. Bolt lengths for ring-type joint flanges include allowance of 15 mm (0.62 in.) for NPS 1 to NPS 3.

  • Bore (B) has to be specified by the buyer

  • Stud Bolt lenghts excl. the height of the chamfers

CLASS 300 WELD NECK ORIFICE FLANGE RF

20180119110237 93422 - How to get high quality orifice flanges?

NPS A R O T H X Tg
1 33.4 50.8 125 36.6 81 54 6.4
1½ 48.3 73 155 36.6 84 70 6.4
2 60.3 92.1 165 36.6 84 84 6.4
2½ 73 104.8 190 36.6 87 100 6.4
3 88.9 127 210 36.6 87 117 9.5
4 114.3 157.2 255 36.6 90 146 12.7
6 168.3 215.9 320 36.6 98 206 12.7
8 219.1 269.9 380 39.7 110 260 12.7
10 273 323.8 445 46.1 116 321 12.7
12 323.8 381 520 49.3 129 375 12.7
14 355.6 412.8 585 52.4 141 425 12.7
16 406.4 469.9 650 55.6 144 483 12.7
18 457 533.4 710 58.8 157 533 12.7
20 508 584.2 775 62 160 587 12.7
24 610 692.2 915 68.3 167 702

12.7

NPS BOLT CIRCLE DIAM. BOLTS # HOLES DIAM. BOLTS DIAMETER BOLTS LENGHT
1 88.9 4 11/16  5/8 125
1½ 114.3 4 13/16  3/4 135
2 127 8 11/16  5/8 125
2½ 149.2 8 13/16  3/4 135
3 168.3 8 13/16  3/4 135
4 200 8 13/16  3/4 135
6 269.9 12 7/8  3/4 135
8 330.2 12 1  7/8 145
10 387.4 16 1 1/8 1    165
12 450.8 16 1¼ 1 1/8 180
14 514.4 20 1¼ 1 1/8 185
16 571.5 20 1 3/8 1¼ 195
18 628.6 24 1 3/8 1¼ 205
20 685.8 24 1 3/8 1¼ 215
24 812.8 24 1 3/8 1½

240

COMMENTS: Height of Raised Face (RF) in CLASS 300 is 2 mm

FLANGE – ORIFICE, WELD NECK, ANSI CLASS 400, B16.36 (IN)

Orifice Flange Jack Screw 1 - How to get high quality orifice flanges?
  • Dimensions to ASME B16.36 – Orifice Flanges
  • Bolt circle diameters are 1/8 inch larger than bolt diameter.
  • All dimensions except “Thickness of Flange C sizes 1” are the same as a Weld Neck.
  • Approximate weight is based on a orifice flange union which is a set of flanges, plate not included.
Pipe Size (NPS) Outside Diameter of Flange A Diameter of Raised Face B Thickness of Flange C Diameter of Bore D Diameter of Hub at Weld H Diameter of Hub at Base J Length of Hub K Number of Bolt Holes Diameter of Bolt Holes Bolt Circle Diameter P Approx. Weight Per Union (lb)
1/2 – – – – – – – – – – –
3/4 – – – – – – – – – – –
1 4 7/8 2 1 1/2 * 1.315 2 1/8 2 7/16 4 3/4 3 1/2 18
1 1/4 5 1/4 2 1/2 1 1/2 * 1.660 2 1/2 2 5/8 4 3/4 3 7/8 20
1 1/2 6 1/8 2 7/8 1 1/2 * 1.900 2 3/4 2 3/4 4 7/8 4 1/2 25
2 6 1/2 3 5/8 1 1/2 * 2.375 3 5/16 2 7/8 8 3/4 5 27
2 1/2 7 1/2 4 1/8 1 1/2 * 2.875 3 15/16 3 1/8 8 7/8 5 7/8 35
3 8 1/4 5 1 1/2 * 3.500 4 5/8 3 1/4 8 7/8 6 5/8 43
3 1/2 – – – – – – – – – – –
4 10 6 3/16 1 3/8 * 4.500 5 3/4 3 1/2 8 1 7 7/8 82
5 11 7 5/16 1 1/2 * 5.563 7 4 8 1 9 1/4 101
6 12 1/2 8 1/2 1 5/8 * 6.625 8 1/8 4 1/16 12 1 10 5/8 136
8 15 10 5/8 1 7/8 * 8.625 10 1/4 4 5/8 12 1 1/8 13 213
10 17 1/2 12 3/4 2 1/8 * 10.750 12 5/8 4 7/8 16 1 1/4 15 1/4 309
12 20 1/2 15 2 1/4 * 12.750 14 3/4 5 3/8 16 1 3/8 17 3/4 429
14 23 16 1/4 2 3/8 * 14.00 16 3/4 5 7/8 20 1 3/8 20 1/4 554
16 25 1/2 18 1/2 2 1/2 * 16.00 19 6 20 1 1/2 22 1/2 705
18 28 21 2 5/8 * 18.00 21 6 1/2 24 1 1/2 24 3/4 863
20 30 1/2 23 2 3/4 * 20.00 23 1/8 6 5/8 24 1 5/8 27 1066
22 33 25 1/4 2 7/8 * 22.00 25 1/4 6 3/4 24 1 3/4 29 1/4 1120
24 36 27 1/4 3 * 24.00 27 5/8 6 7/8 24 1 7/8 32 1555

CLASS 600 WELD NECK ORIFICE FLANGE RF

(ASME B16.5 ASTM A182 F51 ORIFICE FLANGE RF 300LB 10 INCH)

20180119110237 93422 - How to get high quality orifice flanges?

NPS A R O T H X Tg
1 33.5 50.8 125 36.6 81 54 6.4
1½ 48.3 73 155 36.6 84 70 6.4
2 60.3 92.1 165 36.6 84 84 6.4
2½ 73 104.8 190 36.6 87 100 6.4
3 88.9 127 210 36.6 87 117 9.5
4 114.3 157.2 275 38.1 102 152 12.7
6 168.3 215.9 355 47.7 117 222 12.7
8 219.1 269.9 420 55.6 133 273 12.7
10 273 323.8 510 63.5 152 343 12.7
12 323.8 381 560 66.7 156 400 12.7
14 355.6 412.8 605 69.9 165 432 12.7
16 406.4 469.9 685 76.2 178 495 12.7
18 457.2 533.4 745 82.6 184 546 12.7
20 508 584.2 815 88.9 190 610 12.7
24 609.6 692.2 940 101.6 203 718

12.7

NPS BOLT CIRCLE DIAM. BOLTS # HOLES DIAM. BOLTS DIAMETER BOLTS LENGHT
1 88.9 4 11/16 5/8 125
1½ 114.3 4 13/16 3/4 135
2 127 8 11/16 5/8 125
2½ 149.2 8 13/16 3/4 135
3 168.3 8 13/16 3/4 135
4 215.9 8 1 7/8 150
6 292.1 12 1 1/8 1 180
8 349.2 12 1¼ 1 1/8 195
10 431.8 16 1 3/8 1¼ 220
12 489 20 1 3/8 1¼ 230
14 527 20 1½ 1 3/8 240
16 603.2 20 1 5/8 1½ 260
18 654 20 1 3/4 1 5/8 280
20 723.9 24 1 3/4 1 5/8 300
24 838.2 24 2 1 5/8 335

COMMENTS: Height of Raised Face (RF) in CLASS 600 is 2 mm at NPS 1 – NPS 3, and 7 mm at NPS 4 – NPS 24.

CLASS 900 WELD NECK ORIFICE FLANGE RF

20180119110237 93422 - How to get high quality orifice flanges?

NPS R O T H X A Tg
1 50.8 125 36.6 81 54 33.5 6.4
1½ 73 155 36.6 84 70 48.3 6.4
2 92.1 165 36.6 84 84 60.3 6.4
2½ 104.8 190 36.6 87 100 73 6.4
3 127 240 38.1 102 127 88.9 9.5
4 157.2 290 44.5 114 159 114.3 12.7
6 215.9 380 55.6 140 235 168.3 12.7
8 269.9 470 63.5 162 298 219.1 12.7
10 323.8 545 69.9 184 368 273 12.7
12 381 610 79.4 200 419 323.8 12.7
14 412.8 640 85.8 213 451 355.6 12.7
16 469.9 705 88.9 216 508 406.4 12.7
18 533.4 785 101.6 229 565 457.2 12.7
20 584.2 855 108 248 622 508 12.7
24 692.2 1040 139.7 292 749 609.6 12.7
NPS BOLT CIRCLE DIAM. BOLTS # HOLES DIAM. BOLTS DIAMETER BOLTS LENGHT
1 88.9 4 11/16 5/8 125
1½ 114.3 4 13/16 3/4 135
2 127 8 11/16 5/8 125
2½ 149.2 8 13/16 3/4 135
3 190.5 8 1 7/8 150
4 235 8 1¼ 1 1/8 180
6 317.5 12 1¼ 1 1/8 195
8 393.7 12 1½ 1 3/8 230
10 469.9 16 1½ 1 3/8 240
12 533.4 20 1½ 1 3/8 260
14 558.8 20 1 5/8 1½ 280
16 616 20 1 3/4 1 5/8 290
18 685.8 20 2 1 7/8 330
20 749.3 20 2 1/8 2 355
24 901.7 20 2 1/8 2½ 445

COMMENTS: Height of Raised Face (RF) in CLASS 900 is 7 mm.

CLASS 1500 WELD NECK ORIFICE FLANGE RF

20180119110237 93422 - How to get high quality orifice flanges?

NPS R O T H X A Tg
1 50.8 150 38.1 83 52 33.5 6.4
1½ 73 180 38.1 89 70 48.3 6.4
2 92.1 215 38.1 102 105 60.3 6.4
2½ 104.8 245 41.3 105 124 73 6.4
3 127 265 47.7 117 133 88.9 9.5
4 157.2 310 54 124 162 114.3 12.7
6 215.9 395 82.6 171 229 168.3 12.7
8 269.9 485 92.1 213 292 219.1 12.7
10 323.8 585 108 254 368 273 12.7
12 381 675 123.9 283 451 323.8 12.7
14 412.8 750 133.4 298 495 355.6 12.7
16 469.9 825 146.1 311 552 406.4 12.7
18 533.4 915 162 327 597 457.2 12.7
20 584.2 985 177.8 356 641 508 12.7
24 692.2 1170 203.2 406 762 609.6 12.7
NPS BOLT CIRCLE DIAM. BOLTS # HOLES DIAM. BOLTS DIAMETER BOLTS LENGHT
1 101.6 4 1 7/8 150
1½ 123.8 4 1 1/8 1¼ 160
2 165.1 8 1 7/8 150
2½ 190.5 8 1 1/8 1 165
3 203.2 8 1¼ 1 1/8 185
4 241.3 8 1 3/8 1¼ 205
6 317.5 12 1½ 1 3/8 265
8 393.7 12 1 3/4 1 5/8 300
10 482.6 12 2 1 7/8 345
12 571.6 16 2 1/8 2 380
14 635 16 2 3/8 2¼ 415
16 704.8 16 2 5/8 2½ 450
18 774.7 16 2 7/8 2 3/4 500
20 831.8 16 3 1/8 3 545
24 990.6 16 3 5/8 3½ 620

COMMENTS: Height of Raised Face (RF) in CLASS 1500 is 7 mm

CLASS 2500 WELD NECK ORIFICE FLANGE RF

20180119110237 93422 - How to get high quality orifice flanges?

NPS R O T H X A Tg
1 50.8 160 38.1 92 57 33.5 6.4
1½ 73 205 44.5 111 79 48.3 6.4
2 92.1 235 50.8 127 95 60.3 6.4
2½ 104.8 265 57.2 143 114 73 6.4
3 127 305 66.7 168 133 88.9 9.5
4 157.2 355 76.2 190 165 114.3 12.7
6 215.9 485 108 273 235 168.3 12.7
8 269.9 550 127 318 305 219.1 12.7
10 323.8 675 165.1 419 375 273 12.7
12 381 760 184.2 464 441 323.8 12.7
NPS BOLT CIRCLE DIAM. BOLTS # HOLES DIAM. BOLTS DIAMETER BOLTS LENGHT
1 108 4 1 7/8 150
1½ 146 4 1¼ 1 1/8 180
2 171.4 8 1 1/8 1 185
2½ 196.8 8 1¼ 1 1/8 205
3 228.6 8 1 3/8 1¼ 230
4 273 8 1 5/8 1½ 260
6 368.3 8 2 1/8 2 350
8 438.2 12 2 1/8 2 385
10 539.8 12 2 5/8 2½ 490
12 619.1 12 2 7/8 2 3/4 540

COMMENTS: Height of Raised Face (RF) in CLASS 2500 is 7 mm.

WN ORIFICE FLANGE / RTJ

COMMENTS:

  • Dimensions are in millimeters (excl. bolts and bolt holes)
  • Other NPT sizes than 1/2 may be supplied
  • Bolt lengths for raised face flanges include allowance for orifice and gasket thickness of 6 mm (0.25 in.) for NPS 1 to NPS 12 and 10 mm (0.38 in.) for NPS 14 to NPS 24. Bolt lengths for ring-type joint flanges include allowance of 15 mm (0.62 in.) for NPS 1 to NPS 10, 19 mm (0.75 in.) for NPS 12 to NPS 18, and 22 mm (0.88 in.) for NPS 20.
  • Bore (B) is to be specified by the buyer
  • Stud Bolt lenghts excl. the height of the chamfers

CLASS 600 WELD NECK ORIFICE RTJ

20180119110449 97440 - How to get high quality orifice flanges?

NPS O T H GROOVE # P E
1 125 36.6 81 R16 50.8 6.35
1½ 155 36.6 84 R20 68.27 6.35
2 165 36.6 84 R23 82.55 7.92
2½ 190 36.6 87 R26 101.6 7.92
3 210 36.6 87 R31 123.83 7.92
4 275 38.1 102 R37 149.23 7.92
6 355 47.7 117 R45 211.12 7.92
8 420 55.6 133 R49 269.88 7.92
10 510 63.5 152 R53 323.85 7.92
12 560 66.7 156 R57 381 7.92
14 605 69.9 165 R61 419.1 7.92
16 685 76.2 178 R65 469.9 7.92
18 745 82.6 184 R69 533.4 7.92
20 815 88.9 190 R73 584.2 9.53
24 940 101.6 203 R77 692.15 11.13
NPS F R W X A Tg
1 8.74 0.8 25.4 54 33.5 6.4
1½ 8.74 0.8 25.4 70 48.3 6.4
2 11.91 0.8 27 84 60.3 6.4
2½ 11.91 0.8 27 100 73 6.4
3 11.91 0.8 27 117 88.9 9.5
4 11.91 0.8 27 152 114.3 12.7
6 11.91 0.8 27 222 168.3 12.7
8 11.91 0.8 27 273 219.1 12.7
10 11.91 0.8 27 343 273 12.7
12 11.91 0.8 27 400 323.8 12.7
14 11.91 0.8 27 432 355.6 12.7
16 11.91 0.8 30.2 495 406.4 12.7
18 11.91 0.8 30.2 546 457.2 12.7
20 13.49 1.5 31.8 610 508 12.7
24 16.66 1.5 36.5 718 609.6 12.7

CLASS 900 WELD NECK ORIFICE RTJ

20180119110449 97440 - How to get high quality orifice flanges?

NPS O  T H GROOVE # P E
1 125 36.6 81 R16 50.8 6.35
1½ 155 36.6 84 R20 68.27 6.35
2 165 36.6 84 R23 82.55 7.92
2½ 190 36.6 87 R26 101.6 7.92
3 240 38.1 102 R31 123.83 7.92
4 290 44.5 114 R37 149.23 7.92
6 380 55.6 140 R45 211.12 7.92
8 470 63.5 162 R49 269.88 7.92
10 545 69.9 184 R53 323.85 7.92
12 610 79.4 200 R57 381 7.92
14 640 85.8 213 R62 419.1 11.13
16 705 88.9 216 R66 469.9 11.13
18 785 101.6 229 R70 533.4 12.7
20 855 108 248 R74 584.2 12.7
24 1040 139.7 292 R78 692.15 15.88
NPS F R W X A Tg
1 8.74 0.8 25.4 54 33.5 6.4
1½ 8.74 0.8 25.4 70 48.3 6.4
2 11.91 0.8 27 84 60.3 6.4
2½ 11.91 0.8 27 100 73 6.4
3 11.91 0.8 27 127 88.9 9.5
4 11.91 0.8 27 159 114.3 12.7
6 11.91 0.8 27 235 168.3 12.7
8 11.91 0.8 27 298 219.1 12.7
10 11.91 0.8 27 368 273 12.7
12 11.91 0.8 27 419 323.8 12.7
14 16.66 1.5 33.3 451 355.6 12.7
16 16.66 1.5 36.5 508 406.4 12.7
18 19.84 1.5 39.7 565 457.2 12.7
20 19.84 1.5 39.7 622 508 12.7
24 26.97 2.4 47.6 749 609.6 12.7

CLASS 1500 WELD NECK ORIFICE RTJ

20180119110449 97440 - How to get high quality orifice flanges?

NPS O T H GROOVE # P E
1 150 38.1 83 R16 50.8 6.35
1½ 180 38.1 89 R20 68.27 6.35
2 215 38.1 102 R24 95.25 7.92
2½ 245 41.3 105 R27 107.95 7.92
3 265 47.7 117 R35 136.53 7.92
4 310 54 124 R39 161.93 7.92
6 395 82.6 171 R46 211.14 9.52
8 485 92.1 213 R50 269.88 11.13
10 585 108 254 R54 323.85 11.13
12 675 123.9 283 R58 381 14.27
14 750 133.4 298 R63 419.1 15.88
16 825 146.1 311 R67 469.9 17.48
18 915 162 327 R71 533.4 17.48
20 985 177.8 356 R75 584.2 17.48
24 1170 203.2 406 R79 692.15 20.62
NPS F R W X A Tg
1 8.74 0.8 25.4 52 33.5 6.4
1½ 8.74 0.8 25.4 70 48.3 6.4
2 11.91 0.8 27 105 60.3 6.4
2½ 11.91 0.8 27 124 73 6.4
3 11.91 0.8 27 133 88.9 9.5
4 11.91 0.8 27 162 114.3 12.7
6 13.49 1.5 28.6 229 168.3 12.7
8 16.66 1.5 33.3 292 219.1 12.7
10 16.66 1.5 33.3 368 273 12.7
12 23.01 1.5 39.7 451 323.8 12.7
14 26.97 2.4 44.4 495 355.6 12.7
16 30.18 2.4 50.8 552 406.4 12.7
18 30.18 2.4 50.8 597 457.2 12.7
20 33.32 2.4 54 641 508 12.7
24 36.53 2.4 58.7 762 609.6 12.7

CLASS 2500 WELD NECK ORIFICE RTJ

20180119110449 97440 - How to get high quality orifice flanges?

2500#   T H GROOVE # P E
1 160 38.1 92 R18 60.33 6.35
1½ 205 44.5 111 R23 82.55 7.92
2 235 50.8 127 R26 101.6 7.92
2½ 265 57.2 143 R28 111.13 9.53
3 305 66.7 168 R32 127 9.53
4 355 76.2 190 R38 157.18 11.13
6 485 108 273 R47 228.6 12.7
8 550 127 318 R51 279.4 14.27
10 675 165.1 419 R55 342.9 17.48
12 760 184.2 464 R60 406.4 17.48
2500# F R W X A Tg
1 8.74 0.8 25.4 57 33.5 6.4
1½ 11.91 0.8 27 79 48.3 6.4
2 11.91 0.8 27 95 60.3 6.4
2½ 13.49 1.5 30.2 114 73 6.4
3 13.49 1.5 30.2 133 88.9 9.5
4 16.66 1.5 33.3 165 114.3 12.7
6 19.84 1.5 36.5 235 168.3 12.7
8 23.01 1.5 39.7 305 219.1 12.7
10 30.18 2.4 47.6 375 273 12.7
12 33.32 2.4 50.8 441 323.8 12.7

The range of orifice flanges covers all standard sizes and ranges, and all common flange materials. Flanges are available in Welding Neck, Slip On, and Threaded form, and are typically supplied with two 1/2″ NPT tappings in each flange.

ASME B16.36 covers Dimensions and dimensional tolerances from orifice flanges (similar to those covered in ASME B16.5) that have orifice pressure differential connections.

Coverage is limited to the following flanges:

  • WELDING NECK CLASSES 300, 400, 600, 900, 1500, 2500
  • SLIP ON CLASS 300
  • THREADED CLASS 300

Drawing of Orifice Flanges

Orifice Flanges generally come with either Raised Faces or RTJ (Ring Type Joint) facings. They are, for all intensive purposes, the same as weld neck and slip on flanges with extra machining.

20180119110652 99300 - How to get high quality orifice flanges?

Orifice flange for run installation should be so constructed, machined and attached to the that the inner surface of the passage extends through the orifice flange so that there is no recess at the orifice plate.

The flange bore and the section of pipe shall be of the same internal diameter.

Weldneck and Slip-On Orifice Runs

Weldneck and Slip On Orifice Runs - How to get high quality orifice flanges?

Weld Neck Orifice Run

Weld Neck Orifice Run - How to get high quality orifice flanges?

Slip-on Orifice Run

1. End of pipe should be reamed after cutting to ensure a perfectly smooth bore and should enter the flange as shown, for raised face flanges. For ring type joints the ends of the pipe should be a maximum of 3 mm from flange face.

2. The pipe should be drilled through each flange pressure tapping using a 12 mm drill for 4” bore pipe and over, a 10 mm drill for 3” bore pipe and a 6 mm drill for 2½” bore pipe and smaller.

Orifice flange union

Two Orifice Flanges are called an orifice flange union. Each flange comes with two pipe taps for measuring the pressure drop of the flow through an orifice plate.. Orifice plates do not come with the flanges and are sized based on the requirements of the process. Two jack screws are used to spread the flanges apart in order to change the orifice plate. This flange is normally available in weld neck, slip-on, and threaded flanges.

Orifice Flange 1 - How to get high quality orifice flanges?

These flanges have a raised face.

Orifice Flange 2 - How to get high quality orifice flanges?

Orifice Flanges are installed in a straight run of pipe in order to avoid turbulence at the plate. As a rule of thumb, an orifice flange has ten diameters of straight pipe upstream and five diameters of pipe downstream.

An Orifice Flange

An Orifice Flange is intended for use instead of standard pipe flanges when an orifice plate or flow nozzle must be installed. Pairs of pressure tapings are machined into the Orifice Flange, making separate orifice carriers or tapings in the pipe wall unnecessary. This type of flange includes the orifice plate with data tap, a pair of flanges with integrated taps, a set of gaskets, bolts and nuts and a jackscrew to assist separating the flanges for orifice inspection.
Design can be with RF or RTJ weld neck flanges or RF slip-on flanges. The orifice plates are centered within very close tolerances of the standards.
An Orifice plate is a device used for measuring flow rate. Either a volumetric or mass flow rate may be determined, depending on the calculation associated with the orifice plate. It uses the Bernoulli’s principle which states that there is a relationship between the pressure of the fluid and the velocity of the fluid. When the velocity increases, the pressure decreases and vice versa.
An Orifice plate is a thin plate with a hole in the middle. It is usually placed in a pipe in which fluid flows. When the fluid reaches the orifice plate, the fluid is forced to converge to go through the small hole; the point of maximum convergence actually occurs shortly downstream of the physical orifice, at the so-called vena contracta point As it does so, the velocity and the pressure changes. Beyond the vena contracta, the fluid expands and the velocity and pressure change once again. By measuring the difference in fluid pressure between the normal pipe section and at the vena contracta, the volumetric and mass flow rates can be obtained from Bernoulli’s equation.
When installing the orifice plate flange the pressure taps need to be at the same elevation to each other. The assumption when making the calculation for the orifice plate is that static head of the tubes is the same on both sides of the orifice plate. Pressure taps should not be installed facing down as the taps could become plugged with debris in the line.
Weld Neck Orifice Flanges are butt-welded into the pipeline. The inside diameter (bore diameter) of the pipe should be specified when ordering. Weldneck orifice flanges are available in ANSI classes 300, 600, 900, 1500 and 2500. They are not available in ANSI 150 sizes because the thickness of ANSI 150 flanges are not enough to allow for drilling pressure taps.

Installing the orifice plate flange

Orifice flanges are installed in a straight run of pipe in order to avoid turbulence at the plate. As a rule of thumb, an orifice flange has ten diameters of straight pipe upstream and five diameters of pipe downstream.

 20180119110837 75749 - How to get high quality orifice flanges?

Orifice Flange Union

Pipe Tap - How to get high quality orifice flanges? 

Pipe Tap

Jack Screw - How to get high quality orifice flanges? 

Jack Screw

Pipe Taps - How to get high quality orifice flanges?

Pipe Taps

When installing the orifice plate flange the pressure taps need to be at the same elevation to each other. The assumption when making the calculation for the orifice plate is that static head of the tubes is the same on both sides of the orifice plate. Pressure taps should not be installed facing down as the taps could become plugged with debris in the line.

Weldneck orifice flanges are butt-welded into the pipeline. The inside diameter (bore diameter) of the pipe should be specified when ordering. Weldneck orifice flanges are available in ANSI classes 300, 600, 900, 1500 and 2500. They are not available in ANSI 150 sizes because the thickness of ANSI 150 flanges are not enough to allow for drilling pressure taps.

orifice flange1 - How to get high quality orifice flanges?orifice flange2 - How to get high quality orifice flanges?orifice flange3 - How to get high quality orifice flanges?

Orifice flanges are used instead of the standard pipe flanges when orifice plate or flow nozzle is used. The basic purpose for this is to measuring the flow rate of either gases or liquids in the respective pipeline. These flanges are used in various industrial applications and are available in various sizes and materials.

Orifice Flange manufacturer Yaang supplies Orifice Flanges, Plate Flanges, Orifice Plates Fittings in alloy steel, forged steel, ductile iron, Stainless Steel etc.

ASME B1.20.1 covers dimensions and gaging of NPT pipe threads for general purpose applications.

Orifice Flanges cover all standard sizes and ranges, and all common Flange materials

orifice unions come complete with gaskets nuts bolts and jack screws - How to get high quality orifice flanges?

Yaang orifice unions come complete with gaskets, nuts, bolts and jack screws and are made to b16.36 specifications.

Orifice Flange/Plate Sealing Finishes

spaders h - How to get high quality orifice flanges?

Typically, Orifice Flanges and plates are produced as a flat face, raised face or ring joint sealing surface depending on the application requirement. The finishes are identical to the finish under ASME B16.5. The spiral sealing face is a specified finish typically Ra 3.2µm-6.3µm.

Orifice Weld Neck Flanges

Orifice Weld Neck Flanges - How to get high quality orifice flanges?

Orifice Weld Neck Flanges are used instead of the standard pipe flanges when orifice plate or flow nozzle is used.

The basic purpose for this is to measuring the flow rate of either gases or liquids in the respective pipeline. These flanges are used in various industrial applications and are available in various sizes and materials.

Standards, Dimensions & Weight

Weld Neck Orifice Flanges are butt-welded into the pipeline. The inside diameter (bore diameter) of the pipe should be specified when ordering. Weldneck orifice flanges are available in ANSI classes 300, 600, 900, 1500 and 2500.

They are not available in ANSI 150 sizes because the thickness of ANSI 150 flanges are not enough to allow for drilling pressure taps.

  • 300# Slip-On Orifice Flange
  • 300# Weld Neck Orifice Flange
  • 600# Weld Neck Orifice (raised face and RTJ ring type joint) Flange
  • 900# Weld Neck Orifice (raised face and RTJ ring type joint) Flange
  • 1500# Weld Neck Orifice (raised face and RTJ ring type joint) Flange
  • 2500# Weld Neck Orifice (raised face and RTJ ring type joint) Flange

ASME B1.20.1 covers dimensions and gaging of NPT pipe threads for general purpose applications.

Type: Orifice Weld Neck Flange

Materials: Carbon Steel, Alloy Steel, Stainless Steel

Orifice Flange Jack Screw 1 - How to get high quality orifice flanges?

  • ASTM A105
  • A350 LF1, LF2 CL1/CL2, LF3 CL1/CL2
  • A516.60
  • A694 (F42, F46, F48, F50, F52, F56, F60, F65, F70)
  • A182 F304/304L, F316/316L, F316H, F310, F321
  • A182 F11, F22

Welding neck and slip-on Orifice Flanges in class 300 only are conform to ANSI B16.36. Other types and pressure classes are available and sizes larger than 24″ will conform to MSS SP-44. Unions are furnished with gaskets, carbon steel jack screws, pipe plugs for the tapped openings, and bolting per ANSI B16.5.

Tolerances and ratings follow ANSI B16.5 except for the following:

Tolerance for the tap-hole-to-face dimensions

  • ± 0.02″ for flanges < 4″ nominal size
  • ± 0.03″ for flanges ≥ 4″ nominal size

Tolerance for welding neck flange bores

  • ± 0.5% of nominal size

They are made in pressure classes 300 through 2500 lb.; in carbon steel, stainless steel and alloy materials; and raised face or ring joint.

Advantages of Orifice Flanges:

  • It is used for measuring the fluid flow rate in the pipe.
  • It eliminates drilling and making bores on the pipes for inserting instrumentation probes.
  • These are cost saving devices to measure flow rate compared to other expensive methods.
  • Gives accurate readings of flow rate and very reliable.

Source: Network Arrangement – China Orifice Flanges Manufacturer – Yaang Pipe Industry Co., Limited (www.steeljrv.com)

(Yaang Pipe Industry is a leading manufacturer and supplier of nickel alloy and stainless steel products, including Super Duplex Stainless Steel Flanges, Stainless Steel Flanges, Stainless Steel Pipe Fittings, Stainless Steel Pipe. Yaang products are widely used in Shipbuilding, Nuclear power, Marine engineering, Petroleum, Chemical, Mining, Sewage treatment, Natural gas and Pressure vessels and other industries.)

If you want to have more information about the article or you want to share your opinion with us, contact us at sales@steeljrv.com

Please notice that you might be interested in the other technical articles we’ve published:

References:

  • http://www.wermac.org/flanges/flanges_special_orifice-flange_asme-b16.html
  • https://www.pipingonline.com/flanges/orifice_flange-asme_b1636_flange-orifice_wn_flange-orifice_rtj_flange
  • https://www.yaang.com

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