Patent ID: 8807110

Claim:
A system for sampling fluid from a top land piston crevice of a reciprocating piston engine, during operation of the engine, for delivery to analysis equipment, comprising: a tubing having a first end that provides fluid communication into the crevice via a bore through the piston wall; a piloted check valve whose input end is connected to the second end of the tubing; a relief valve on the tubing between the crevice and the piloted check valve, operable to open fluid flow from the crevice when a compression pressure of the engine results from a near top dead center position of the piston; a sample line connected to the output end of the piloted check valve; a sample container for receiving fluid from the piloted check valve via the sample line; wherein the piloted check valve is operable to close fluid communication between the crevice and the sample container just prior to a predetermined rise in combustion chamber pressure.