BS 4504 Flange
BS 4504 Flange
BS 4504 Flange refers to a series of flanges that are designed and manufactured according to the British Standard 4504. This standard is commonly used in the UK and other regions where British standards are adopted, and it outlines the dimensions, pressure ratings, and material requirements for flanges used in piping systems.
Type of BS 4504 Flange
BS 4504 Weld Neck Flange
BS 4504 Slip-on Flange
BS 4504 Blind Flange
BS 4504 Threaded Flange
BS 4504 Socket Weld Flange
BS 4504 Flange Dimension
| Nominal Size (DN) | Nominal Pressure (PN) | Bolt Circle Diameter (D) | No. of Bolts (N) | Bolt Hole Diameter (d) | Flange Thickness (T) | Raised Face (RF) | Hub Length (L) | Flange Weight |
|---|---|---|---|---|---|---|---|---|
| DN 10 | PN 10, PN 16 | 70 mm | 4 | 10 mm | 12 mm | 2 mm | 20 mm | 0.35 kg |
| DN 15 | PN 10, PN 16 | 80 mm | 4 | 10 mm | 12 mm | 2 mm | 20 mm | 0.45 kg |
| DN 20 | PN 10, PN 16 | 90 mm | 4 | 10 mm | 12 mm | 2 mm | 20 mm | 0.55 kg |
| DN 25 | PN 10, PN 16 | 100 mm | 4 | 10 mm | 14 mm | 2 mm | 20 mm | 0.65 kg |
| DN 40 | PN 10, PN 16 | 120 mm | 8 | 12 mm | 16 mm | 2 mm | 30 mm | 1.1 kg |
| DN 50 | PN 10, PN 16 | 130 mm | 8 | 12 mm | 16 mm | 2 mm | 30 mm | 1.3 kg |
| DN 80 | PN 10, PN 16 | 150 mm | 8 | 12 mm | 18 mm | 2 mm | 30 mm | 1.8 kg |
| DN 100 | PN 10, PN 16 | 160 mm | 8 | 12 mm | 18 mm | 2 mm | 30 mm | 2.2 kg |
| DN 150 | PN 10, PN 16 | 190 mm | 12 | 16 mm | 20 mm | 3 mm | 40 mm | 3.4 kg |
| DN 200 | PN 10, PN 16 | 220 mm | 12 | 16 mm | 22 mm | 3 mm | 40 mm | 4.2 kg |
Pressure Rating
- PN 2.5: Low-pressure flanges, suitable for lower-pressure systems.
- PN 6: Typically used for general low-pressure applications.
- PN 10: Common for medium-pressure systems.
- PN 16: Commonly used for medium-pressure applications, including water and steam systems.
- PN 25: Higher-pressure applications, suitable for more demanding environments.
Tolerance
- Diameter Tolerances:
- The outside diameter (OD) of the flange and the bolt hole circle diameter are subject to specific tolerances to ensure they fit with pipe dimensions and bolt pattern requirements.
- For instance, the outside diameter tolerance is generally around +1.5 mm / -0 mm for flanges within certain size ranges (depending on the size of the flange).
- Bolt Hole and Bolt Circle Tolerances:
- The bolt hole diameter tolerance is usually ±0.2 mm.
- The bolt hole spacing (bolt circle diameter) tolerance can range from ±0.5 mm to ±1.0 mm, depending on the flange size and type.
- Thickness Tolerances:
- The thickness of the flange typically has a tolerance of ±0.5 mm for certain sizes, but it can vary based on the pressure class and flange type.
- Flange Facing Tolerances:
- For flanges with a raised face, the height tolerance is usually around ±0.2 mm.
- For flat-faced flanges, there might be a ±0.5 mm tolerance for the overall flatness.
- The surface finish (e.g., roughness) is also part of the tolerance, especially for sealing surfaces. This is often given as a specific Ra value.
- Angle Tolerances:
- The angle of certain flange parts like the raised face or bevels can typically have a tolerance of ±1 degree.
Applications
- Oil and gas
- Petrochemical
- Power generation
- Water and wastewater treatment
- Chemical processing