Couplings for non-ferrous pipe

Claim 1

A coupling for joining two sections of non-ferrous pipe, at least one of said sections having an end portion which is tapered inwardly toward its extremity, said coupling comprising a female coupling element having a first end with a tapered inner wall portion complementary to said tapered end portion of said one pipe section for receiving the same and a second end with a threaded inner wall portion, a male coupling element adapted to be secured about an end of the remaining pipe section, said male coupling element having an externally threaded portion for threadably engaging said threaded inner wall portion of said female coupling element and having a terminal portion with a cylindrical, non-tapered outer surface receivable within said female coupling element in advance of said externally threaded portion, and a tubular liner for effecting a fluid seal between said pipe sections when said coupling elements are threadably engaged, said liner having an internal circumferential web adjacent one end thereof for forming a lip seal against said outer surface of said male coupling element, said liner further having a tapered sleeve portion at an opposite end thereof for sealingly engaging, along its outer surface, said tapered inner wall portion of said female coupling element and for sealingly engaging, along its inner surface, said tapered end portion of said one pipe section.