Hydraulic Check Valves are a common hydraulic control component. Its core feature is to control the one-way flow of oil so that it can only pass in one direction and the reverse direction is blocked. It plays a vital role in hydraulic systems.
One-way conductivity: This is the most core feature, allowing fluid (usually hydraulic oil) to flow freely in a specific direction (forward) while effectively blocking the flow in the opposite direction (reverse).
Simple and reliable structure: The typical one-way valve structure consists of a valve body, a valve core (commonly a steel ball or a cone valve core) and a spring. This structure makes it relatively easy to manufacture and maintain, and it works very reliably.
Quick response: When the forward flow is opened, the valve core opens quickly; when there is a reverse flow trend, the valve core can be quickly closed under the action of the spring force (sometimes combined with the oil pressure) to block the oil circuit.
Low forward opening pressure: A well-designed one-way valve has a low opening pressure (pressure difference required to overcome the spring preload) when flowing in the forward direction, so the pressure loss to the system is small.
Good reverse sealing: In the reverse cut-off state, the valve core (especially the cone valve core) and the valve seat can usually form a line seal or a surface seal, which has good sealing performance and effectively prevents internal leakage and backflow.
Function of limiting or controlling flow: Some specially designed one-way valves (such as one-way valves with throttle holes) can perform appropriate throttling control on the flow when opening.
The main functions of hydraulic one-way valves in the system are:
Maintaining one-way flow in the oil circuit: This is the most basic and most widely used function. For example, prevent the pressure oil from flowing back and damaging the pump when the oil pump stops working; prevent the actuator (such as hydraulic cylinder) from unexpected action (such as falling or retracting) caused by load gravity or external force.
Pressure maintenance: In the pressure maintenance circuit, the one-way valve is used to close the oil circuit at one end of the cylinder or accumulator to prevent pressure drop due to small leakage or pressure fluctuations in the system and maintain the required pressure.
Locking (hydraulic lock): In combination with a hydraulically controlled check valve or two ordinary check valves (one for each inlet and outlet oil circuit), a "hydraulic lock" can be formed to firmly lock the hydraulic cylinder or motor in a certain position to prevent it from moving under external force.
Used as a back pressure valve: By replacing a spring with a higher stiffness, Hydraulic Check Valves can provide a reverse opening pressure (back pressure) in the oil outflow direction, which is used to increase the back pressure of the actuator return oil circuit and improve the smoothness of movement (prevent creeping).
Bypass function: In complex circuits, check valves can be used to form bypass oil circuits to achieve certain specific action requirements (such as differential circuits in fast forward-working forward conversion).
Hydraulic Check Valves, with their reliable "one-way cut-off" characteristics, are indispensable basic components in ensuring the safety of hydraulic systems (anti-backflow, locking), maintaining performance (pressure maintenance, stability) and realizing specific circuit functions. Its simple and reliable structure and clear function make it one of the most frequently used valves in hydraulic systems.
