California Plumbing Code – PEX (Part 1)

This section covers the rules and guidelines for installing PEX (cross-linked polyethylene) and PEX-AL-PEX (cross-linked polyethylene-aluminum-cross-linked polyethylene) tubing in California. Let’s break down the key points:

PEX Installation Guidelines

• PEX is a type of plastic tubing used for water supply lines. There are also composite versions like PEX-AL-PEX, which include aluminum for added strength.
• Before using a new PEX installation, the pipes must be flushed twice over the course of a week. First, flush the system for at least 10 minutes, then fill it and let it sit for a week. If the system is used before a week has passed, run the water for at least 2 minutes before using it for drinking or cooking.
• Contractors must provide written proof that they followed the flushing procedure. A final inspection and approval won’t happen until it’s verified that the installation meets the code.
• If a contractor fails to comply, they can face penalties under the Health and Safety Code.

Water Heater Connections 

• Flexible metallic connectors used to connect water heaters to the plumbing must follow the standard regulations.
• Copper or stainless steel connectors cannot be longer than 24 inches.
• PEX tubing cannot be used within the first 18 inches of piping connected to a water heater.

PEX Tubing and Joints

• PEX tubing and fittings must be installed following the manufacturer’s instructions and sections of the California Plumbing Code.
• All PEX pipes installed must be UV-protected for at least 30 days to prevent sun damage.

Fittings

• PEX tubing must be installed according to the manufacturer’s guidelines. It cannot be used for purposes that would violate the California Building Standards Code.

PEX-AL-PEX Plastic Tubing and Joints

• PEX-AL-PEX tubing cannot be used for potable (drinking) water systems in California.

Mechanical Joints

• Crimp joints for PEX-AL-PEX are made by compressing a crimp ring around the pipe, forcing the material into the fitting. However, PEX-AL-PEX is not approved for drinking water systems.

Compression Joints

• Similar to mechanical joints, compression joints for PEX-AL-PEX are not approved for drinking water systems.

Installation Standards for Composite Piping Systems

• Composite piping systems like PEX-AL-PEX and PE-AL-PE (Polyethylene-Aluminum-Polyethylene) must meet specific standards for hot and cold water distribution systems. These systems must comply with the requirements of ASTM F 1281, ASTM F 1282, and ASTM F 1974 for fittings.

Relevant Sections from the Uniform Plumbing Code (UPC)

These are the sections of the UPC that apply to PEX-AL-PEX and PE-AL-PE tubing:

• 309.0: Workmanship standards.
• 312.0: Protection of pipes, materials, and structures.
• 605.0: Joints and connections.
• 605.17.2: Plastic pipe to other materials.

ASTM refers to the American Society for Testing and Materials, and IAPMO is the International Association of Plumbing and Mechanical Officials. The UPC (Uniform Plumbing Code) is published by IAPMO and applies to these materials and installations.