THREE-WAY TWO-POSITION POPPET-TYPE PALM-BUTTON-OPERATED PNEUMATIC DIRECTIONAL VALVE MECHANISM

The directional valve shown in Fig. a can be employed either as a normally closed or normally open valve, which is mechanically operated from one side. When used as a normally closed valve, compressed air is supplied from the main to port 1, and port 2, the outlet port, is connected through a channel in valve member 5 to port 3, which is connected to the atmosphere. The valve is operated by pressi…