by increase the flange class inner diameter and diameter of the raised face at all the same; but outside diameter, bolt circle and diameter of bolt holes become larger in each higher pressure class.
| Pressure-Temperature Ratings for ASTM Group 2-1.1 Materials | |||||||
| Working pressure by Classes, BAR | |||||||
| Temp °C | 150 | 300 | 400 | 600 | 900 | 1500 | 2500 |
| -29 to 38 | 19.6 | 51.1 | 68.1 | 102.1 | 153.2 | 255.3 | 425.5 |
| 50 | 19.2 | 50.1 | 66.8 | 100.2 | 150.4 | 250.6 | 417.7 |
| 100 | 17.7 | 46.6 | 62.1 | 93.2 | 139.8 | 233 | 388.3 |
| 150 | 15.8 | 45.1 | 60.1 | 90.2 | 135.2 | 225.4 | 375.6 |
| 200 | 13.8 | 43.8 | 58.4 | 87.6 | 131.4 | 219 | 365 |
| 250 | 12.1 | 41.9 | 55.9 | 83.9 | 125.8 | 209.7 | 349.5 |
| 300 | 10.2 | 39.8 | 53.1 | 79.6 | 119.5 | 199.1 | 331.8 |
| 325 | 9.3 | 38.7 | 51.6 | 77.4 | 116.1 | 193.6 | 322.6 |
| 350 | 8.4 | 37.6 | 50.1 | 75.1 | 112.7 | 187.8 | 313 |
| 375 | 7.4 | 36.4 | 48.5 | 72.7 | 109.1 | 181.8 | 303.1 |
| 400 | 6.5 | 34.7 | 46.3 | 69.4 | 104.2 | 173.6 | 289.3 |
| 425 | 5.5 | 28.8 | 38.4 | 57.5 | 86.3 | 143.8 | 239.7 |
| 450 | 4.6 | 23 | 30.7 | 46 | 69 | 115 | 191.7 |
| 475 | 3.7 | 17.4 | 23.2 | 34.9 | 52.3 | 87.2 | 145.3 |
| 500 | 2.8 | 11.8 | 15.7 | 23.5 | 35.3 | 58.8 | 97.9 |
| 538 | 1.4 | 5.9 | 7.9 | 11.8 | 17.7 | 29.5 | 49.2 |
| Pressure-Temperature Ratings for ASTM Group 2-2.3 Materials | |||||||
| Working pressure by Classes, BAR | |||||||
| Temp °C | 150 | 300 | 400 | 600 | 900 | 1500 | 2500 |
| -29 to 38 | 15.9 | 41.4 | 55.2 | 82.7 | 124.1 | 206.8 | 344.7 |
| 50 | 15.3 | 40 | 53.4 | 80 | 120.1 | 200.1 | 333.5 |
| 100 | 13.3 | 34.8 | 46.4 | 69.6 | 104.4 | 173.9 | 289.9 |
| 150 | 12 | 31.4 | 41.9 | 62.8 | 94.2 | 157 | 261.6 |
| 200 | 11.2 | 29.2 | 38.9 | 58.3 | 87.5 | 145.8 | 243 |
| 250 | 10.5 | 27.5 | 36.6 | 54.9 | 82.4 | 137.3 | 228.9 |
| 300 | 10 | 26.1 | 34.8 | 52.1 | 78.2 | 130.3 | 217.2 |
| 325 | 9.3 | 25.5 | 34 | 51 | 76.4 | 127.4 | 212.3 |
| 350 | 8.4 | 25.1 | 33.4 | 50.1 | 75.2 | 125.4 | 208.9 |
| 375 | 7.4 | 24.8 | 33 | 49.5 | 74.3 | 123.8 | 206.3 |
| 400 | 6.5 | 24.3 | 32.4 | 48.6 | 72.9 | 121.5 | 202.5 |
| 425 | 5.5 | 23.9 | 31.8 | 47.7 | 71.6 | 119.3 | 198.8 |
| 450 | 4.6 | 23.4 | 31.2 | 46.8 | 70.2 | 117.1 | 195.1 |
When standard elbow is trimmed the trimmed end will not be a circle. it will be slightly elliptical and that may create problems with welding and NDT
The raised face flange provide a relatively large contact area. Where metal gaskets are used with this facing, the gasket area should be reduced to increase the gasket compression.
The primary ASME standards for piping dimensions are:
- ASME B36.10M: For wrought steel pipe.
- ASME B36.19M: For stainless steel pipe.
- ASME B16.5: For flanges and flanged fittings.
- ASME B16.9: For butt-welding fittings.
- ASME B16.11: For forged fittings.
- ASME B16.25: For butt-welding ends.
- ASME B16.34: For valves.
- ASME B1.20.1 Pipe thread dimensions
Use FOT(flat on top) eccentric reducers in pump suction line to avoid accumulation of gas pockets.
Use eccentric reducers are for slurry systems and where it is imperative to totally drain ALL condensed fluid, eccentric reducers can avoid small “dead spots” that
exist behind concentric reducers