Interpretation Response #PI-89-009

Interpretation Response Details

June 9, 1989

Mr. Ellen Bardenhagen
Gas Engineering Department
Long Island Lighting Company
175 East Old Country Road
Hicksville, New York 11801

Dear Ms. Bardenhagen:

Thank you for your letter requesting clarification of the requirements for qualifying mechanical joining methods for plastic pipe. We understand your question to be whether the word "material" as used in §192.283(b)(7) refers to any class of plastic polymers (e.g., 2306 polyethylene) or to a specific polymer within a class used by a particular pipe manufacturer.

The qualification of a mechanical joining method depends on the tensile strength of the pipe material under load, as opposed to the physical-chemical properties that are pertinent for other joining methods (e.g., heat fusion, solvent cement). Since each class has a minimum tensile strength, a class of plastic polymers suffices to describe the material for which a mechanical joining method is qualified. Therefore, test information that qualifies a mechanical joining method for use on one manufacturer's pipe made from a specific polymer in a class would also qualify that method for use on any other manufacturer's pipe made from any other polymer in that class.

I hope that this discussion has clarified the issue for you. If you have any further questions, please contact me.

Sincerely,

Richard L. Beam
Director
Office of Pipeline Safety

Regulation Sections