How to get high quality 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.
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
| 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)
|
|
| 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)
| 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
| 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
| 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
| 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
| 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
| 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
| 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
| 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.
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
Weld Neck Orifice Run
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.
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These flanges have a raised face. |
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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.
Orifice Flange Union |
Pipe Tap |
Jack Screw |
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 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
Yaang orifice unions come complete with gaskets, nuts, bolts and jack screws and are made to b16.36 specifications.
Orifice Flange/Plate Sealing Finishes
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 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
- 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: 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
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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
