Abstract: A rotary machine is provided with a casing and an atmosphere relief mechanism (20) for closing an opening (12) for atmospheric release formed in the casing and relieving pressure of inner fluid to atmosphere when a pressure in the casing rises. The atmosphere relief mechanism includes: a rupture disc (24) configured to rupture when the pressure in the casing reaches a predetermined pressure; a pair of annular holding parts (22, 27) arranged to hold an outer edge of the rupture disc from both sides; a plurality of fastening members (29) for fastening the pair of annular holding parts to each other so as to hold the rupture disc between the pair of annular holding parts; and an annular spacer part (25) provided along an outer circumference of the rupture disc.

Abstract: It is intended to provide a rotary machine provided with an atmosphere relief mechanism by which damage of a rupture disc when attaching the disc can be prevented and which can withstand use over a long period of time. The rotary machine is provided with a casing and an atmosphere relief mechanism 20 for closing an opening 12 for atmospheric release formed in the casing and relieving pressure of inner fluid to atmosphere when a pressure in the casing rises. The atmosphere relief mechanism 20 includes: a rupture disc 24 configured to rupture when the pressure in the casing reaches a predetermined pressure; a pair of annular holding parts 22, 27 arranged to hold an outer edge of the rupture disc 24 from both sides; a plurality of fastening members 29 for fastening the pair of annular holding parts 22, 27 to each other so as to hold the rupture disc 24 between the pair of annular holding parts 22, 27; and an annular spacer part 25 provided along an outer circumference of the rupture disc 24.