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.