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INTRODUCTION

Plastic pressure pipes and fittings are commonly used in applications such as hot- and cold-water plumbing, fire protection, and hydronic heating and cooling systems, including radiant distribution systems. In certain instances, pipes and fittings are installed inside areas that must be insulated, such as within a ceiling or wall cavity. In other cases, the pipes and fittings themselves must be insulated to reduce the transfer of heat through the pipe wall.

This Technical Note provides guidance about proper application of spray polyurethane foam insulation to avoid damage due to excessive heat surrounding the following types of plastic pressure pipe, tubing, and fitting materials:

• CPVC: chlorinated polyvinyl chloride

• PEX: crosslinked polyethylene

• PEX/AL/PEX: crosslinked polyethylene/aluminum/crosslinked polyethylene

• PERT/AL/PERT: polyethylene of raised temperature resistance/aluminum/polyethylene of raised temperature resistance

• PE-RT: polyethylene of raised temperature resistance

• PP-R: random copolymerized polypropylene

• PP-RCT: polypropylene random copolymer with modified crystallinity & temperature resistance

• PSU: polysulfone

• PPS: polyphenlysulfone

• PPSU: polyphenylene sulfide

• PVDF: polyvinylidene fluoride

Much of the information in this document is provided by the Spray Polyurethane Foam Alliance (SPFA) which is an excellent source of knowledge of these types of insulation products and proper installation in numerous applications.

This document does not address required insulation values for pipes in various applications. For that type of information, please see PPI TN-65 Insulation Recommendations for Plastic Pressure Piping Materials in Residential Applications.

NOTE 1: This document does not apply to other types of spray foam such as that used for fireblock or firestop.