Plastic piping can play a key role in reducing the costs of residential fire sprinkler systems and thus make them more economically viable. The feasibility of using plastic pipe for this application has been shown in numerous demonstrations.

In utilizing plastic pipes, their particular characteristics and properties must be considered. For example, only plastics with demonstrated high temperature capabilities are accepted by plumbing codes for use in hot and cold water distribution systems in residential and commercial buildings.

Selection of plastic pipe for residential fire sprinkler systems must recognize the full range of conditions that may be reasonably encountered in use. For example, attic temperatures in buildings can range from 32° to over 140°F. In addition, the piping could pass next to localized heat sources such as recessed lighting fixtures, heating pipes, hot water pipes, and heat producing appliances. These temperature effects must be taken into account in selecting piping materials.

In light of the foregoing, the Plastic Pipe and Fittings Association recommends that the following guidelines be utilized in the selection, design, and installation of thermoplastic pipe in residential fire sprinkler systems:

1. Thermoplastic pipe shall only be used for wet pipe fire sprinkler systems.
2. Thermoplastic pipe fire sprinkler systems shall be installed so that they are protected from freezing.
3. Plastic piping systems considered for this application should have the capability of obtaining a working pressure rating (50 year) of 125 psi at 140° F. Plastic piping with lower temperature/pressure rating should be used only where climatic conditions result in maximum temperatures below 90°F.
4. The preferred thermoplastic pipe systems for this application are those that are pressure rated for elevated temperatures; e.g., hot water distribution piping which carries a 100 psi rating at 180°F.
5. All thermoplastic piping in sprinkler systems shall be shielded by wallboard or other protective material.
6. All thermoplastic piping used in sprinkler systems shall be a potable water grade and carry the NSF seal.
7. Thermoplastic piping systems shall be protected from any heat source such as heating pipes, recessed light fixtures, hot air ducts, etc. This can be accomplished by the use of insulation or by separating the pipe from the heat source.

NOTE:
This PPFA User Bulletin is designed to provide guidance in achieving the efficient, effective and informed use of plastic pipe. The suggestions and advice contained in this Bulletin are offered merely to provide plastic pipe users with a general frame of reference. Because specific situations may, and often do require special treatment, the suggestions and advice are obviously not universally applicable. Therefore, the user should carefully assess the requirements of his specific situation before making practical application of anything contained in this publication.