Pipe joint

Claim 1

A PIPE JOINT BETWEEN ADJACENT PIPE SECTIONS, EACH OF THE PIPE SECTIONS COMPRISING AN OUTER RIGID BODY AND A LINING OF A SYNTHETIC RESINOUS MATERIAL SUBJECT TO COLD FLOW, EACH OF THE PIPE SECTIONS HAVING A TERMINAL END TO BE JOINED, A FLANGE AFFIXED TO THE RIGID OUTER LAYER OF EACH PIPE SECTION AND DEFINING A GENERALLY OUTWARDLY EXTENDING RADIAL SURFACE, EACH FLANGE HAVING AN ANNULAR GROOVE WITHIN THE OUTWARDLY EXTENDING SURFACE, THE GROOVES BEING OF SUBSTANTIALLY THE SAME RADIUS, MEANS TO SECURE ADJACENT FLANGES TO EACH OTHER, A TERMINAL FLANGE OF SYNTHETIC THERMOPLASTIC RESINOUS MATERIAL INTERGRAL WITH THE LINING IN EACH PIPE SECTION AND EXTENDING ALONG A CENTRALLY LOCATED GENERALLY CIRCULAR PORTION OF THE RADIALLY OUTWARDLY EXTENDING FACE OF THE AFFIXED FLANGE, AN ORING OF A RESILIENT SEALING MATERIAL DISPOSED IN SAID GROOVES, THE AXIAL DEPTH OF EACH OF THE GROOVES BEING LESS THAN THE RADIUS OF THE O-RING CROSS-SECTION, THE GROOVES BEING DISPOSED ADJACENT THE OUTER TERMINAL PORTION OF THE SYNTHETIC RESINOUS FLANGES AND WITHIN THE MEANS TO SECURE ADJACENT FLANGES TO EACH OTHER, SAID SECURING MEANS DRAWING SAID FLANGES TOGETHER TO COMPRESS SAID O-RING AND THE TERMINAL FLANGES TO THEREBY EFFECT A DOUBLE SEAL AT SAID JOINT INTERFACE.