the invention provides for a rubber sleeve for sealing of the joint between a branch pipe 27 and a main pipe 21 . a sleeve is provided with an annular lip 3 that can ensure correct positioning of the sleeve in relation to the inner side of a main pipe 21 . when fitting a branch pipe 27 this is secured in relation to a sleeve by a strapping band 31 so that relative movement may be prevented . the branch pipe can then be prevented from slide into the main pipe and project into the bore of the main pipe and cause obstruction of matter flowing in the main pipe 21 .