Patent ID: 9046098
Filing Date: 2015-06-02
Classification: F04B,F16K

Abstract:
1. A method of operating a face sealing annular valve of a fluid-working machine, the valve having a valve body and an annular valve seat, the valve seat comprising a first annular sealing surface having a first circumference, a second annular sealing surface having a second circumference which is different from the first circumference, and which is coaxial with the first sealing surface, and at least one aperture between the first and second sealing surfaces providing a fluid pathway through the body of the valve; and an elastically deformable annular valve member having a first annular seat-engaging surface configured to cooperate with the first annular sealing surface, and a second seat-engaging surface, the annular valve member having a relaxed configuration in which the first seat-engaging surface is sized to sealedly engage with the first sealing surface and in which the second seat-engaging surface is disposed in relation to the first seat-engaging surface such that the second sealing surface and the second seat-engaging surface do not sealedly engage when the first sealing surface and the first seat-engaging surface are in sealing engagement; the method comprising bringing the first seat-engaging surface into sealing engagement with the first sealing surface; elastically deforming the annular valve member from the relaxed configuration to a deformed configuration so as to bring the second seat engaging surface into sealing engagement with the second sealing surface, to thereby restrict the flow of fluid through the fluid pathway; and pivoting the second seat-engaging surface around the first seat-engaging surface to bring the second seat-engaging surface into sealing engagement with the second sealing surface when the annular valve member transits from the relaxed configuration to the deformed configuration.