Resources & Guides / Building Codes & Standards / ASTM & UL Standards / ASTM F877
ASTM F877
Standard Specification for Crosslinked Polyethylene (PEX) Plastic Hot- and Cold-Water Distribution Systems
Overview
ASTM F877 covers crosslinked polyethylene (PEX) tubing and fittings used in hot and cold water distribution systems. PEX is a flexible plastic piping material that has revolutionized plumbing installations through its resistance to scale and chlorine, flexibility for fewer connections, and ability to expand without bursting in freezing conditions. The standard covers PEX-a, PEX-b, and PEX-c manufacturing methods.
Performance Requirements
- Pressure ratings: 160 psi at 73°F, 100 psi at 180°F
- Temperature resistance: Continuous operation up to 200°F
- Chlorine resistance: 4.3 ppm chlorine at 140°F for 50-year life
- UV resistance requirements for outdoor storage
- Burst pressure testing and long-term hydrostatic strength
Installation Advantages
PEX flexibility allows for continuous runs with fewer fittings, reducing potential leak points. The material can be snaked through walls and around obstacles, minimizing demolition during retrofits. Home-run manifold systems eliminate hidden joints in walls. PEX expansion during freezing provides freeze-break resistance superior to rigid piping, though it's not freeze-proof and must still be protected from sustained freezing.
Code Compliance and Limitations
ASTM F877 is referenced in major plumbing codes including the IPC and UPC. However, PEX has limitations: it cannot be used outdoors exposed to UV light, requires protection from physical damage, and isn't suitable for compressed air systems. Some jurisdictions restrict PEX use in certain applications. Proper support spacing (32" for 1/2" horizontal runs) and expansion compensation must be provided per manufacturer instructions.