Rubber Expansion Joint -- Single Arch EPDM NBR
Moulded Single-Arch Rubber Expansion Joint for Pipeline Movement and Vibration Isolation
Document No.SV-DS-EXP-001
RevisionRev A
DateMay 2026
ManufacturerSupreme Valves India, Ahmedabad, Gujarat, India
This datasheet covers single-arch moulded rubber expansion joints in EPDM or NBR with fabric and wire reinforcement for absorbing thermal expansion, vibration isolation, and misalignment in water, HVAC, and chemical pipelines.
Technical Specifications
| Parameter | Specification |
|---|
| Size Range | DN25 to DN600 (1" to 24") |
| Pressure Rating | PN10 / PN16 |
| Body Material | EPDM or NBR moulded rubber with nylon / polyester cord reinforcement |
| Reinforcement | Nylon or polyester tyre cord plies; steel wire helix for vacuum resistance |
| Flange Material | Integral rubber flange with steel backing ring (optional) |
| Temperature Range | EPDM: -40°C to +120°C; NBR: -30°C to +80°C |
| Movement Capability | Axial: 10-50 mm; Lateral: 10-30 mm; Angular: 10-15° (size dependent) |
| End Connections | Flanged BS EN 1092-1 PN10/16 or ASME B16.5 Class 150 with integral rubber flange face |
| Features | Single arch, multi-directional movement, vibration isolation, vacuum rated, integral flange face |
| Accessories | Limit rods, control units, tie rods for unrestrained installation |
Materials of Construction
| Component | Material |
|---|
| Rubber Body | EPDM or NBR compound, moulded with nylon / polyester cord reinforcement and wire helix |
| Cord Reinforcement | Nylon or polyester tyre cord plies (typically 2 to 6 plies depending on size and pressure) |
| Wire Helix | Carbon steel or SS304 wire helix embedded in rubber for vacuum and external pressure resistance |
| Flange Face | Integral moulded rubber flange face with raised sealing beads; no separate gasket required |
| Backing Ring | Carbon steel or SS304 split backing ring for high-pressure or vacuum service (optional) |
| Limit Rods | Carbon steel or SS304 threaded rods with nuts and washers to prevent over-extension |
Testing & Inspection
| Test | Requirement |
|---|
| Test Standard | Hydrostatic 1.5x PN; vacuum 0.08 MPa without collapse |
| Certification | CE, ISO 9001, WRAS on request for potable water |
Applicable Standards
| Standard | Description |
|---|
| Design Standard | ISO 10628 / BS 6129 |
Notes
- Expansion joint must be installed with sufficient pipe guides and anchors to prevent excessive lateral or angular movement beyond rated capability.
- For unrestrained installation (no anchors), specify control rods or limit rods sized to absorb full thrust force at test pressure.
- EPDM is suitable for water, wastewater, and dilute chemicals; NBR for oil-contaminated water and hydrocarbon service.
- Vacuum rating requires wire helix; without wire helix, arch may collapse under negative pressure and restrict flow.
- Do not expose rubber expansion joints to direct sunlight or ozone for extended periods; specify protective cover for outdoor installation.
