WRAS Approval: Navigating UK Water Regulations for Rubber Seals.
WRAS Approval: Navigating UK Water Regulations for Rubber Seals
Problem Statement
EPDM seals in potable water systems fail after 18 months due to chlorine-induced cracking (≥2 ppm residual Cl2). Standard compounds exhibit 40% compression set loss at 70°C/1,000 hrs.
Material Science Analysis
- Failure Mechanism: Chlorine attacks unsaturated polymer chains in generic EPDM (4-5% ENB content).
- Solution: RubberQ's WRAS-approved EPDM uses 8% ENB with peroxide curing, reducing chain mobility and oxidative degradation.
Technical Specifications
| Parameter | RubberQ EPDM (WRAS) | Standard EPDM | FKM Alternative |
|---|---|---|---|
| Shore A Hardness | 70 ±2 | 68 ±5 | 75 ±3 |
| Tensile Strength (MPa) | 14.5 | 9.8 | 16.2 |
| Elongation at Break (%) | 320 | 280 | 210 |
| Compression Set (70°C/1,000 hrs) | ≤15% | 40% | ≤10% |
| Chlorine Resistance (2 ppm/5 yrs) | No cracking | Cracks at 18 months | Overkill |
Standard Compliance
- IATF 16949-controlled compounding ensures ≤2% batch variance in ENB content.
- Full PPAP documentation including ASTM D2000 material callouts and ISO 3601 leak testing.
- Traceability: Raw material lot numbers embedded in molded seals via laser marking.
For custom material compound development or IATF 16949 documentation, consult RubberQ's engineering department.
