scope:

INTRODUCTION

Random copolymerized polypropylene (PP-R) is a high-temperature plastic pressure piping system used for plumbing and hydronic heating and cooling applications. PP-R was launched in the 1980s in Europe, then introduced to North America in the 2000s.

PP-R product standards include:

• ASTM F2389 Standard Specification for Pressure-rated Polypropylene (PP) Piping Systems, first published in 2004 www.astm.org

• CSA B137.11 Polypropylene (PP-R) pipe and fittings for pressure applications, first published in 1993 www.shopcsa.ca

This Technical Note will explain how improper or excessive flow rates within mixed-material plumbing systems that contain both copper materials (i.e. tubing, fittings, valves) combined with PP-R piping materials can result in premature failure of both the copper components and the PP-R materials, potentially resulting in plumbing system leaks.

These concerns do not apply to copper alloy materials, such as brass or bronze, or to cold-water plumbing, hydronic systems, closed-loop geothermal systems or industrial piping systems.

This Technical Note will explain the conditions that can result in premature failure of copper or PP-R piping materials, and how to avoid these problems through proper design, sizing and balancing of plumbing systems.

Note 1: While this technical note is specific to PP-R piping materials, the recommendations regarding proper sizing of and intergrating with copper tubing and components may also be applicable to other plastic piping materials approved for plumbing applications.

Note 2: For more information about proper sizing of copper plumbing systems and the potential for corrosion of copper, see the Copper & Copper Alloy Corrosion Resistance Database available from the Copper Development Association at www.copper.org and the Canadian Copper & Brass Development Association at http://en.coppercanada.ca/.