Hydraulic valves are a vital feature of hydraulic power systems. They regulate the flow and pressure of water or oil in the systems. Valves also control volume of fluid that flows through the system. This helps to sustain a balanced state of power dynamics in various hydraulic systems. Different types of valves can be used in a single system. Each type of valve is designed to perform some specific activity which contributes to the overall smooth operation of the unit. Hydraulic valves can be broadly divided into three categories. These are the flow control, pressure and directional valves.
1. Flow Control Hydraulic Valves
These valves monitor and regulate the rate at which fluids flow in hydraulic systems. The valve is designed to react to fluctuations in pressure within a circuit. When the pressure attains a certain level, the valve will shut or open based on the setting. This relieves high pressure where it occurs in a system. In this way, a balance is attained with other parts of the system. When a mechanical system is not operational, the flow valves prevent the flow of fluid under the influence of gravity. The valves keep fluid in a standby mode which prevents its flow within the system. Flow dividers are a type of flow control valve. They receive fluid from one flow source but divide the flow into two or more outputs in a mechanical system. The flow divider may deliver the resultant flows in equal flow rates or maintain a different rate for each output flow.
2. Pressure Hydraulic Valves
These regulate the pressure of water as it flows through hydraulic systems. They help to keep the pressure of flid below the set limit. Pressure valves also maintain the desired pressure in part of a circuit. Various types of pressure valves work in different ways to enable correct pressure in hydraulic systems. Counter-balance valves prevent hydraulic systems from extreme accelerations. This creates dynamic control within a circuit which helps to balance the system. Unloading valves are used to relieve pressure when it gets to extreme levels. Pressure regulators manage pressure fluctuations and help to stabilize water pressure. They can also be used to set the pressure at which oil will flow into a circuit. Sequence valves are designed to detect pressures besides the maximum pressure in a system. This enables them to determine the sequence of hydraulic operations. They can sequentially open two different sections of a mechanical system.
3. Directional Valves
These are designed to perform any of three actions. They direct the flow of fluid in a hydraulic system in a particular direction. They can halt or initiate the flow of fluid in a system. Directional valves can also change the direction in which a fluid flows within a circuit. Various directional valves are incorporated in hydraulic systems to enable proper flow of fluids. The check valve permits the flow of fluid in one direction but prevents a flow in the opposite direction. It can also regulate pressure. Spool valves are designed to block and allow the flow of fluid within a hydraulic system.