5/2 Directional control valve 5/3 Directional control valve 1.2.1.2 POPPET DIRECTION CONTROL VALVES There are two different types of poppet valves, namely ball seat valve and disc seat valve. A.Ball seat valve. In a poppet valve, discs, cones or balls are used to control flow. Figure 1.1 shows the construction of a simple 2/2 normally closed valve. If the push button is pressed, ball will lift off from its seat and allows the air to flow from port P to port B. When the push button is released, spring force and air pressure keeps the ball back and closes air flow from port P to port B. Valve position are shown in Figure 1.1(a) 1.1 (b) 1.1(C) Figure 1.1 Two/Two Ball seat Poppet valve B. Disc seat poppet valve Figure 1.2 shows the construction of a disc type 3/2 way DCV. When push button is released, ports 1 and 3 are connected via hollow pushbutton stem. If the push button is pressed, port 3 is first blocked by the moving valve stem and then valve disc is pushed down so as to open the valve thus connecting port 1 and 3. When the push button is released, spring and air pressure from port 1 closes the valve.. Comparison between Ball seat and disc seat valve is given in Table 1.3
5/2 Directional control valve 5/3 Directional control valve 1.2.1.2 POPPET DIRECTION CONTROL VALVES There are two different types of poppet valves, namely ball seat valve and disc seat valve. A.Ball seat valve. In a poppet valve, discs, cones or balls are used to control flow. Figure 1.1 shows the construction of a simple 2/2 normally closed valve. If the push button is pressed, ball will lift off from its seat and allows the air to flow from port P to port B. When the push button is released, spring force and air pressure keeps the ball back and closes air flow from port P to port B. Valve position are shown in Figure 1.1(a) 1.1 (b) 1.1(C) Figure 1.1 Two/Two Ball seat Poppet valve B. Disc seat poppet valve Figure 1.2 shows the construction of a disc type 3/2 way DCV. When push button is released, ports 1 and 3 are connected via hollow pushbutton stem. If the push button is pressed, port 3 is first blocked by the moving valve stem and then valve disc is pushed down so as to open the valve thus connecting port 1 and 3. When the push button is released, spring and air pressure from port 1 closes the valve.. Comparison between Ball seat and disc seat valve is given in Table 1.3