Abstract: This invention pertains to equipment for sealing pipe joints and particularly a collar for sealing a leaking underground gas main with an absolute minimum of excavation. The procedure as currently practiced for accomplishing this result includes the installation of a rubber collar through a narrow bore hole which can then be clamped to the bell and spigot joint by means of bands. It is then filled with a sealant injected through a suitable inlet in the collar under pressure in excess of that in the gas main. The present collar provides improvements by eliminating gas pockets which have heretofore formed when the sealant is introduced into the collar and also means for sealing leaks in gas mains carrying pressure on the order of 50 psi.