Patent ID: 6039359
Filing Date: 2000-03-21
Classification: F16L,Y10S

Abstract:
A pipe joint construction comprising in combination:a tubular concrete first pipe section having an annular front end and provided with a tubular steel spigot projecting forwardly from the front end, the spigot terminating in a leading end and forming an annular ring groove spaced rearwardly from the leading end,a resilient gasket positioned in the ring groove,a tubular concrete second pipe section having an annular rear end and provided with a steel bell projecting rearwardly from the rear end and having an inside annular face,the spigot inserted into the bell in end-to-end relationship with the gasket compressed in the ring groove by the inside annular face,a sleeve made of a polyurethane foam material having an inorganic alkaline releasing material dispersed therein, the alkaline releasing material being reactive with water to hydrate thereby forming an alkaline substance to protect exposed steel,the sleeve having a moisture impervious outward surface and a moisture pervious inward surface,the sleeve spanning from the first pipe section to the second pipe section sealing outwardly a joint formed therebetween, the sleeve extending annularly about the joint and over end margins of both of said pipe sections to protect embedded steel in the margins from corrosion due to surface cracks, andeach of said outer margins connected to the sleeve by means of a tightening band.