Abstract: The present invention provides:a lining material comprising a flexible fabric tube which is a circularly knitted fabric comprising a ground and a plurality of tufts of fabric projecting from the ground on the inside thereof, and a flexible sleeve within the tube, the flexible sleeve being substantially impervious to at least one of a gas and a liquid and being capable of being inflated in use to generally radially outwardly bear on the tube to force the tube in use into general conformity with an orifice.