Reed valve

[1] A one-way valve used in a two-cycle engine. It is made of a flat strip of metal that lies on the floor of the crankcase over a hole connected to the carburetor. As the piston moves up, the vacuum developed in the crankcase lifts the reed valve off the hole. The vacuum causes the fuel-air mixture to flow from the carburetor into the crankcase. Then, as the piston starts to move down, pressure increases in the crankcase pushing the reed valve down, closing the hole and sealing the crankcase.
[2] Wafer-thin metal plate located in the valve plate of an automotive compressor which act as suction and discharge valves. The suction valve is located on the underside of the valve plate; the discharge valve is situated on the top.