Abstract: An annular flange member is provided which is adapted to be provided around a fluid passage opening of a housing of a hydraulic machine to connect a fluid conduit means to the fluid passage opening. The annular flange member comprises an inside surface facing the housing, an outside surface opposite the inside surface, and a through hole extending from the inside surface to the outside surface and fluidly communicated with the fluid passage opening. The outside surface is provided with an O-ring receiving groove surrounding the through hole which is formed by a half die cutting press operation. A hydraulic machine is provided which includes a flange member as noted above.

Abstract: There is provided a hydraulic turbomachine comprising a housing, one or more impellers arranged rotatably around an axis within the housing, one or more resin-made diffusers provided around the one or more impellers for defining diffuser channels around the impellers, respectively, one or more support members provided within the housing and engaged under pressure with corresponding ones of the diffusers for securely supporting the corresponding diffusers in the direction of the above-noted axis within the housing, and elastic members held between surfaces of the support members and the diffusers in the above-noted direction. An O-ring receiving groove is formed in each of the surfaces of the diffusers in such a manner that the groove surrounds the axis, and an O-ring is placed in the groove as the elastic member.