Directional control hydraulic valves are of three types:
* Check valve – These valves stop the liquid flow in one direction and allow free flow in the other direction.
* Directional Spool Valve – They have a moving spool which connects or separates the channels in the housing. These hydraulic valves are the best.
* Directional Poppet Valve – They are fitted into the housing bores with a thread like connection.