A compressor has a high-pressure relief valve and a low-pressure relief
valve. The high-pressure relief valve in use for a discharge region opens
when the pressure of gas in the discharge region is more than a first
predetermined pressure. The high-pressure relief valve is provided with a
first shim. The low-pressure relief valve in use for a suction region
opens when the pressure of gas in the suction region is more than a second
predetermined pressure which is lower than the first predetermined
pressure. The low-pressure relief valve is provided with a second shim.
The high-pressure relief valve and the low-pressure relief valve have
similar structure to each other.
