Kingston Check Valves designed for lubricated compressor applications will not perform in non-lubricated systems. Internal parts on these valves require lubrication provided to the compressor. If installed on an oil-free compressor these valves will wear prematurely and possibly cause damage to the compressor.
The Model 205, for example, has an internal piston to dampen the hammering effects of some compressors. The piston and sleeve are precision engineered to fit snugly and require oil to keep from overheating and wearing quickly or seizing.