Abstract: A method of making a sealing member for association with a bore in a barrel member comprises cutting into and rolling a thin layer from a rod of circular cross-section, preferably made of P.T.F.E., leaving the rolled layer integral with the support, forming an annular groove in the support for an elastomeric sealing ring, unrolling the rolled layer so as to form a sheath which covers the ring and so as to leave a rolled portion of the sheath on one side of the ring which forms a resilient annular bulge in the sheath, and compressing the rolled portion whereby the sealing ring is sealed on both its sides by the sheath.

Abstract: A method of making a sealing member and a sealing member made by the method, for association with a bore in a barrel member comprises cutting into and rolling a thin layer from a rod of circular cross-section, preferably made of P.T.F.E., leaving the rolled layer integral with the support, forming an annular groove in the support for an elastomeric sealing ring, unrolling the rolled layer so as to form a sheath which covers the ring and so as to leave a rolled portion of the sheath on one side of the ring which forms a resilient annular bulge in the sheath, and compressing the rolled portion whereby the sealing ring is sealed on both its sides by the sheath.