PTFE Expansion Joint -- Convoluted PTFE SS316 Flanges
Convoluted PTFE Expansion Joint for Chemical and Pharmaceutical Pipeline Flexibility
Document No.SV-DS-EXP-002
RevisionRev A
DateMay 2026
ManufacturerSupreme Valves India, Ahmedabad, Gujarat, India
This datasheet covers convoluted PTFE expansion joints with SS316 wire reinforcement and backing flanges for chemical resistance and multi-directional movement absorption in pharmaceutical, semiconductor, and chemical process piping.
Technical Specifications
| Parameter | Specification |
|---|
| Size Range | DN25 to DN300 (1" to 12") |
| Pressure Rating | PN10 / PN16 / Class 150 |
| Body Material | Virgin PTFE convoluted bellows with SS316 wire reinforcement |
| Flange Material | SS316 backing flanges with PTFE overflanged face |
| Temperature Range | -40°C to +180°C (PTFE limit) |
| Movement Capability | Axial: 15-40 mm; Lateral: 10-25 mm; Angular: 8-12° (size dependent) |
| End Connections | Flanged ASME B16.5 / BS EN 1092-1 with PTFE overflanged face |
| Features | Universal chemical resistance, FDA PTFE, vacuum rated, convoluted profile, SS316 flanges |
| Accessories | Limit rods, control units, protective shroud |
Materials of Construction
| Component | Material |
|---|
| PTFE Bellows | Virgin PTFE, isostatically moulded and sintered, convoluted profile for flexibility |
| Reinforcement | SS316 wire helix embedded in PTFE wall for vacuum and external pressure resistance |
| Flange Face | PTFE overflanged face extending beyond steel backing flange; no separate gasket required |
| Backing Flanges | SS316 slip-on or weld-neck backing flanges to retain PTFE overflange |
| Gasket | PTFE envelope or no gasket required due to overflanged integral seal |
| Limit Rods | SS316 threaded rods with nuts and washers for unrestrained installations |
Testing & Inspection
| Test | Requirement |
|---|
| Test Standard | Hydrostatic 1.5x PN; vacuum 0.08 MPa without collapse |
| Certification | CE, FDA, ISO 9001 |
Applicable Standards
| Standard | Description |
|---|
| Design Standard | ISO 10628 / BS 6129 |
Notes
- PTFE cold-flow limits maximum pressure to PN16 / Class 150 at ambient; derate 25% at 150°C and 40% at 180°C.
- Convoluted PTFE joints must be supported with adequate pipe guides and anchors; excessive lateral movement can tear PTFE convolutions.
- For unrestrained installation, specify SS316 limit rods sized for full pressure thrust at test pressure.
- Do not use with fluorinated solvents, molten alkali metals, or elemental fluorine -- these chemically attack PTFE.
- Protective SS316 shroud is recommended for outdoor installation to prevent UV degradation and mechanical damage to PTFE surface.
