Directional control valves are used to control the flow of hydraulic fluid from one or more sources into different paths, ensuring that they follow a specific path. This is usually controlled by a spool within the valve box, which is mechanically or electrically actuated (moved) to prevent or allow flow. Hence the name directional control valve. The hydraulic valve is used to control the flow direction of the oil in the hydraulic system or adjust its flow and pressure. As a kind of hydraulic valve, the directional control valve controls the flow direction of the oil by changing the flow channel. The types of directional control valves include check valve, hydraulic control check valve, reversing valve, stroke deceleration valve, filling valve, shuttle valve, etc.
The directional control valve is a component used to control the flow direction and air flow of the compressed air in the pipeline. It is the most widely used type of valve in the pneumatic system. According to the action direction of the air flow in the valve, the directional control valve can be divided into two types: one-way directional control valve and reversing directional control valve. A directional control valve that only allows airflow in one direction is called a one-way directional control valve, such as one-way valve, shuttle valve, double-pressure valve, etc. A directional control valve that can change the direction of airflow is called a reversing directional control valve, or reversing valve for short.
Hydraulic Check Valves: These are the simplest and most common directional control valves often used in hydraulic systems. These valves can be used to block fluid flow in one direction while still allowing fluid to flow freely in the opposite direction. These models are also commonly referred to as check valves.
Directional spool: Consists of a moving spool located within the valve housing. The driving force then moves the control spool, allowing the passages within the housing to be connected or disconnected.
Directional poppet valves: Mounted in housing bores with threaded connections, which is why they are often referred to as cartridge valves, and can contain a range of seat elements, including balls, poppets, and plates.
There are four main types of power for directional control valves: manual, these use a simple lever or paddle where the operator applies force to operate; mechanical, which applies force through the use of cams, wheels, rollers and other mechanisms, which means they subject to wear; hydraulics, which operate at much higher pressures than their pneumatic counterparts; solenoids, widely used in the hydraulics industry, which use electromechanical solenoids to slide the spool.