ClipArt ETC
An illustration of the valve with lap at the end of the crank end steam compression. The piston will restart the compression cycle of at the head of the piston. As the piston moves, the sliding valve in the top compartment will fill with steam and closes.

Steam Engine Valve with Lap Steam Where Slide Valve is in Open Position

An illustration of the valve with lap at the end of the crank end steam compression. The piston will…