Ductile Iron Backing Ring
Ductile iron backing ring for clamping polyethylene stub ends and securely bolting pipelines to valves, pumps, and water infrastructure.
- Cast from high-grade ductile iron delivering elevated yield strength and impact resistance
- Standardized bolt circle and hole patterns strictly compliant with EN 1092-2
- Superior resilience against environmental oxidation and pipeline vibration stresses
- Available across standard PN10 and PN16 pressure ratings for municipal piping
- Optimized compressive load distribution protecting PE stub shoulders from damage
Key Specifications
- Product code
- P091
- Reference standard
- EN 1092-2
- Material & grade
- Ductile iron
- Outside diameter
- 63–630 mm
- Nominal pressure (at 20 °C)
- PN10 to PN16
- Unit of sale
- Piece
- Applications
- Drinking water supply, Sewage
- Dimensional options
- 22 rows in the specification table
Metallurgical properties and usage of ductile iron rings
The ductile iron backing ring (spheroidal graphite iron) is widely specified in municipal water treatment plants, pumping chambers, and industrial manifolds. Spheroidal graphite nodules impart superior tensile ductility and fracture toughness compared to traditional gray iron, preventing brittle cracking under high bolt torquing loads.
Dimensionally aligned with EN 1092-2 flange specifications, these rings integrate seamlessly with cast and ductile iron gate, butterfly, and check valves. The inherent oxidation resistance of ductile iron delivers extended service life in humid underground valve chambers with minimal maintenance.
Size range and bolting recommendations
Ductile iron backing rings are typically manufactured to match PE stub end outside diameters from 63 to 630 mm across PN10 and PN16 pressure ratings.
During flange fit-up, inserting a reinforced elastomeric EPDM gasket between the mating faces and torquing the bolts in crosswise stages with a torque wrench prevents shear stress concentrations on the PE shoulder. Specify your required pipe outside diameters and pressure classes in our quote form for submittals.
Ductile Iron Backing Ring — Technical Specifications
Wall thickness and weight are calculated from the standard series and are approximate; final values are confirmed in the quotation.
| Outer Diameter (mm) | Nominal Pressure (bar) |
|---|---|
| 63 | 10 |
| 63 | 16 |
| 90 | 10 |
| 90 | 16 |
| 110 | 10 |
| 110 | 16 |
| 125 | 10 |
| 125 | 16 |
| 160 | 10 |
| 160 | 16 |
| 200 | 10 |
| 200 | 16 |
| 250 | 10 |
| 250 | 16 |
| 315 | 10 |
| 315 | 16 |
| 400 | 10 |
| 400 | 16 |
| 500 | 10 |
| 500 | 16 |
| 630 | 10 |
| 630 | 16 |
Ductile Iron Backing Ring — FAQ
What sizes are typical for ductile iron backing rings?
These rings typically match PE stub end outside diameters from 63 to 630 mm in PN10 and PN16 classes.
What is the primary advantage of ductile iron over gray iron?
Ductile iron features spherical graphite nodules, providing high ductility and shock resistance, preventing brittle fracture.
Does the bolt pattern conform to standard valve flanges?
Yes, manufactured to EN 1092-2 specifications, the bolt circle coordinates with standard ductile iron and cast iron valves.
Does ductile iron corrode rapidly in moist chambers?
No, ductile iron forms a protective oxide patina and is commonly coated with protective epoxy primer to prevent rust.
