The California Air Tools "Easy Start Valve" is designed to release some air at start up to allow the motor/pump to start under a no load condition.

California Air Tools Air Compressors.

CAT-4620A, CAT-10020, CAT-4620AC, CAT-4620AC-22060,CAT-10020C, CAT-10020C-22060, CAT-15020C, CAT-15020C-22060