Final answer:
A discus compressor's valve plate design offers higher efficiency through superior sealing and minimal clearance volume, which reduces energy loss during the compression cycle compared to conventional piston compressors.
Step-by-step explanation:
The main advantage that a discus compressor's valve plate design has over a conventional piston-type compressor is the efficiency of its operation. The discus compressor valve plate allows for superior sealing and minimum clearance volume, resulting in higher efficiency during the compression cycle. Unlike in a conventional piston compressor where the exhaust valve opens and some of the combustion products escape while the volume remains constant, leading to energy loss, the discus compressor design minimizes this wastage by reducing the dead space where these gases could remain.
In the discus compressor, as the piston moves and the valve plate flexes, the valve remains in close proximity to the piston, allowing for a rapid opening and closing action which helps to efficiently expel the combustion products and reduce re-expansion losses.