Strengthened pipe fitting and method

Abstract

A strengthened pipe fitting for connecting to an externally threaded surface and a method for making a strengthened pipe fitting for connecting to an externally threaded surface is provided. The strengthened pipe fitting comprises a pipe fitting having an internally threaded surface initiating from the attachment end and a compression band fitted onto the attachment end of the pipe fitting. The pipe fitting is initially manufactured, in absence of the compression band, to have an internally threaded surface with a pitch diameter larger than that specified for mating with the externally threaded surface. The compression band is then fitted onto the attachment end of the pipe fitting. The compression band is uniquely sized to compress the internally threaded surface sufficiently so that the internally threaded surface of the strengthened pipe fitting mates with the externally threaded member. Since the compression band compresses the attachment end of the pipe fitting, the pipe fitting is subjected to a compressive preload. Thus, the expansion load upon the internally threaded surface which occurs during wrench tight engagement with the externally threaded member is reduced by the preexisting compressive load subjected upon the strengthened pipe fitting.