Final answer:
A clearance pocket design is used in reciprocating compressors to reduce the clearance volume.
Step-by-step explanation:
In a reciprocating compressor, a compressor valve design that reduces clearance volume is called a clearance pocket design.
This design uses a pocket or chamber between the valve seat and the valve plate to reduce the clearance volume. When the piston moves down, the gas is compressed into the clearance pocket, reducing the amount of gas that needs to be re-compressed during the next stroke.
This reduces the work required by the compressor and improves its efficiency.