Three position five way valve control double acting cylinder reversing circuit

Figure a shows the reversing circuit with the middle closed three position five way valve (O type), which is suitable for the situation that the piston stops in the middle of the stroke. However, due to the compressibility of the gas, the piston stop position accuracy is poor, and there is no leakage in the circuit and valve.

Figure B shows the reversing circuit with the middle relief three position five way valve (Y type). When the piston stops, this circuit can push the piston to move freely with external force (if manual device can be added). Its disadvantage is that the piston inertia has a great influence on the stop position and is not easy to control. Generally, it cannot be used for lifting system.

Figure C shows the reversing circuit of the double piston rod cylinder controlled by the middle position pressurized three position five way valve (P type). This circuit is suitable for small piston area, which requires the piston to stop quickly in the middle of the stroke. The disadvantage is that if the cylinder is a single piston rod, due to the effect of "differential pressure", when the system passes through the air source and there is no control signal, the cylinder will extend slowly. Similarly, it can not be used in lifting system.