Hydraulic directional valves refers to a hydraulic directional valve is composed of two or more valves as the main body,

and according to different working requirements as well as assisting devices such as shock valves, one-way valves,

and charge valves. The selector valves can be divided into hydraulic manual directional valve, hydraulic solenoid directional valve,

electric-hydraulic valves, pneumatic valves, etc. according to the way of operating the hydraulic control valve movement.