Coupling and/or joining lined pipe

Claim 1

A liquid tight coupling for threadless pipe comprising: a. a double walled fitting with an outer casing and a lining, said outer casing having an annular flange extending axially outward beyond the end face of said lining, the inner surface of said flange having an outward opening taper; b. a length of doubled wall threadless pipe with an outer sheath and an inner lining, the lining being of a deformable material, said pipe having one end extending into said annular flange and a portion of the lining said pipe extending axially beyond and radially outward over the end of the sheath of said pipe to form a washer of pipe lining material which is integral with and a continuation of said pipe lining, said washer being in fluid tight abutment with the end face of said fitting lining; c. a ferrule on said pipe adjacent said washer, said ferrule having a tapered outer surface extending into said annular fitting flange, said ferrule being clamped between said pipe and the tapered inner surface of said fitting flange; d. said washer of pipe lining material having the outer periphery thereof engaged by said fitting flange and deformed thereby to extend said washer outer periphery axially back over at least a portion of the tapered outer surface of said ferrule between said ferrule and the tapered inner surface of said fitting flange; and e. means engaging said ferrule and fitting for maintaining said fitting and pipe clamped together in fluid tight engagement.