Introduction
The recent recognition of PP-RCT material in DIN standards for water pressure pipes marks a significant evolution in plumbing technology. While this development primarily concerns polypropylene systems, it raises important questions about parallel advancements in PEX press fittings – the dominant solution for modern plumbing installations.

This article examines:
- Key changes in the updated DIN standards
- How PEX press fittings compare to PP-RCT systems
- Implications for specifiers and installers
Understanding the New DIN Standards
DIN 8077/8078 Updates (2024)
- Recognizes PP-RCT (Polypropylene Random Crystallinity Temperature) as a premium pipe material
- Establishes new pressure ratings:
- PN 20 (20 bar at 20°C)
- PN 25 (25 bar at 20°C)
- Expands temperature range to 95°C continuous operation
Comparison: PP-RCT vs. PEX Press Fittings
Parameter | PP-RCT | PEX Press Fittings |
---|---|---|
Max Temperature | 95°C | 90°C |
Pressure Rating | PN 25 | 16 bar |
Installation Method | Heat fusion | Mechanical press |
Freeze Resistance | Moderate | Excellent |
Material Cost | $$ | $$$ |
Labor Cost | $ | $$ |
Why PEX Press Fittings Remain Competitive
1. Installation Efficiency
- 50% faster than PP-RCT fusion welding
- No hot work permits required
- Reversible connections available (some systems)
2. Material Advantages
- Superior flexibility (bend radius = 8× OD)
- No thermal expansion joints needed up to 30m runs
- Proven 50+ year lifespan in field applications
3. Evolving Standards
- DIN 16892/16893 updates for PEX-AL-PEX
- New DIN SPEC 12211 for press connection systems
Best Practices for PEX Press in High-Pressure Systems
1. System Design Considerations
- Use PEX-AL-PEX for PN 20+ applications
- Include expansion loops every 20 feet
- Specify brass press fittings for critical connections
2. Quality Assurance
- Third-party certification (DVGW, KIWA, NSF)
- Batch testing of fittings (per EN ISO 15875)
- Annual tool calibration requirements
5 FAQs About PEX Press Fittings and New Standards
1. Are PEX press fittings compliant with the new DIN standards?
Yes – when installed per DIN 4726 for plastic piping systems.
2. Can PEX press systems achieve PN 25 ratings?
Only PEX-AL-PEX multilayer systems meet PN 25 when properly designed.
3. How do material costs compare between PP-RCT and PEX?
PEX press systems cost 20-30% more but save 40% in labor.
4. Is special training required for PEX press installations?
Yes – most manufacturers require certification courses (8-16 hours).
5. Will PP-RCT replace PEX in commercial applications?
Unlikely – each has niche advantages (PEX for retrofit, PP-RCT for industrial).
Industry Outlook
- 2025 Projection: 15% growth in PEX press for high-rise buildings
- Technology Trends:
- Smart press tools with connection verification
- Biofilm-resistant PEX formulations
- Thinner PEX-OB with maintained pressure ratings
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