Flange Bolt Sets
Bolt sets are supplied in bagged sets containing the appropriate number of bolts, nuts and washers for each flanged joint. A standard set is used to bolt one ductile iron flange to another, whereas extra length bolts are required when connecting a PE stub flange to a ductile iron flange.
Bolt Types
The standard finish to bolt sets is galvanised steel to BS 4 190. A number of finishing options are available depending upon the specification requirement and site conditions.
- Rilsan coated
- Stainless steel
- Sheridised
- Zinc plated
Applications
Flanged joints are both rigid and self-anchoring. Used in above ground situations such as Pumping Stations, Treatment Works, and Industrial Pipelines. Also used in below ground when connecting fittings such as Valves and Hydrants.
The seal between flanged ends is achieved by axial compression of a flat gasket between the flanges, which is tightened with bolt sets, as shown above.
Flange Specifications
The standard flange drilling is normally PN16, on pipes and fittings for working pressures up to and including 16 Bar. Other drilling configurations (PN10, PN25, PN40) require the corresponding number and size of bolts in a set for the specified drilling arrangement.
Bolt sets (Extra Long) for PN16 flanges - DI x PE Joint
| Flange Diameter | Bolts in Set | Bolt Size (mm) | Code |
|---|---|---|---|
| 50mm | 4 | M16x65 | 0820BS50GALV |
| 80mm | 8 | M16x65 | 0820BS80GALV |
| 100mm | 8 | M16x65 | 0820BS100GALV |
| 150mm | 8 | M20x70 | 0820BS150GALV |
| 200mm | 12 | M20x70 | 0820BS200GALV |
| 250mm | 12 | M24x90 | 0820BS250GALV |
| 300mm | 12 | M24x90 | 0820BS300GALV |
| 350mm | 16 | M24x90 | 0820BS350GALV |
| 400mm | 16 | M27x100 | 0820BS400GALV |
| 450mm | 20 | M27x100 | 0820BS450GALV |
| 500mm | 20 | M30x110 | 0820BS500GALV |
| 600mm | 20 | M33x120 | 0820BS600GALV |
Bolt sets (Extra Long) for PN16 flanges - DI x PE Joint
| Flange Diameter | Bolts in Set | Bolt Size (mm) | Code |
|---|---|---|---|
| 80mm | 8 | M16x80 | 082080BSDIPEG |
| 100m | 8 | M16x80 | 0820100BSDIPEG |
| 150mm | 8 | M20x90 | 0820150BSDIPEG |
| 200mm | 12 | M20x90 | 0820200BSDIPEG |
| 250mm | 12 | M24x100 | 0820300BSDIPEG |
Flange Bolt Set Installation
Bolts should be tightened in the correct sequence and to the appropriate torque. The sequence is determined by the number of bolts in the flange set, however it generally follows a 1,3,2,4 pattern. Torque is determined by the pipe bore and the Bar rating desired (refer to fitting manufacture’s tables).
- Check that gasket is correct diameter and matches flange drillings
- Clean flange faces & position gasket
- Check size & number of bolts (only use rust free undamaged bolts)
- Lubricate bolt threads with automotive grease
- Tighten bolts in correct sequence
- Gasket normally suffers some relaxation
- Check and re-tighten bolts, if necessary ‘before’ pressure testing
Flange Gaskets
Flange gaskets are available in several formats and are manufactured from a wide range of materials. The most common combination is the full face type made of EPDM, used for jointing ductile iron flanges together (two lug or IBC Ring types are also available). The standard thickness is 3mm, however 4mm and 6mm are also available on request.
Features & Benefits - EPDM Gasket
- WRAS approved for potable water usage
- Good resistance to heat, weathering, ozone effects, ketones and esters
- Not suitable for contact with petroleum liquids, oils, solvents or fats
- Temperature range between -40°C and +120°C
Applications - EPDM Gasket
Full face gaskets are used between two ductile iron flanges, the gasket covers the full face of the flanges and so is holed to suit the bolt positions.
EPDM Full Face Flange Gaskets
| Flange Diameter | Code |
|---|---|
| 50mm | 0820G50FFE |
| 80mm | 0820G80FFE |
| 100mm | 0820G100FFE |
| 150mm | 0820G150FFE |
| 200mm | 0820G200FFE |
| 250mm | 0820G250FFE |
| 300mm | 0820G300FFE |
| 350mm | 0820G350FFE |
| 400mm | 0820G400FFE |
| 450mm | 0820G450FFE |
| 500mm | 0820G500FFE |
| 600mm | 0820G600FFE |