Directional Valve Animation Of 4 Way / 3 Position  Explanation:

There are 4 hydraulic oil ports, which is A, B, O, P ports. The P port is oil inlet port connects to supply oil piping and O port is oil outlet port drains oil to reservoir. The A & B are oil control ports, connects to other hydraulic actuator, like cylinders. The 4/3 spool directional control valve is mostly used in hydraulic system machines, controls hydraulic flow direction. The 3 position means the spool have 3 different stage, on the left, central and right position, which achieves different hydraulic operation. – finotek.com

Directional Valve Animation Of 5 Way / 3 Position  Explanation:

There are 5 oil ports of this valve, one inlet port and two outlet ports. This valve function is similar with 4/3 valve, except 2 drain ports. All the ports are sealed when the spool in the middle. The flow is exerted from P inlet port to B port and drained by O ports when the spool on the left position. On the right position of the spool, the oil flows into A ports through P and the return oil is exerted to other drain port. – finotek.com