Patent attributes
An annular valve in which the shape of a sealing surface of a valve body is optimized thus suppressing the occurrence of pressure loss in gas on the periphery of the sealing surface and extending the service life of the annular valve. The annular valve comprises: a valve seat 10 formed in a plate-like shape and including passage flow channels 11 each having an opening cross section formed in an arcuate shape; a receiving plate 20 formed in a plate-like shape and having discharge flow channels 21, the receiving plate 20 being arranged to face the valve seat 10 by way of an intermediate chamber 50; a valve body 30 formed in an annular shape corresponding to the arcuate shape of the opening cross section of the passage flow channel 11 and being arranged in the intermediate chamber 50, the valve body 30 being brought into contact with/separated from the valve seat 10 so as to open/close the passage flow channel 11; and a plurality of spring members 40 supported by the receiving plate 20, the spring members 40 each biasing elastically the valve body 30 toward the valve seat 10. A sealing surface 31 of the valve body 30 that faces the passage flow channel 11 is formed in a shape where at least one of pressure loss elements with respect to gas flowing towards the valve body 30 from the passage flow channel 11 is eliminated.