Abstract: Apparatus is provided for introducing sealant into a clearance between a replacement pipe 9 and an existing pipe 36 within which in use the replacement pipe 9 is located. The apparatus comprises a nose-cone 1 having a tubular body 6 for connection to the upstream end 8 of the replacement pipe 9, frangible means 20 in the form of a pop-out plug; pierceable metal foil; plastic film or membrane to seal the bore of the tubular body 6 and at least one non return valve 2 in the form of an elastic ring 2, rubber O-ring 40 or plug 52 and spring assembly 53 to permit the flow of sealant from the bore of the body 6 into the clearance 37 by way of the wall of the body 6 but to resist return-flow from the clearance 37 into the bore.