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Guide for Working principle of Hydraulic Flow Control Valve

Flow valves are vital in regulating the pressure and flow rate of fluids in a flow channel. They optimize the system functions depending on the channel cross-section area. In this write-up, we will check the works of hydraulic flow control valves and principles of operations.

What is a Hydraulic System?

A hydraulic system is a process that uses a fluid to move energy from one point to another. A good example is when you move energy from an electric motor to a hydraulic cylinder that works as an actuator. We assume that the fluid path can be flexible in this system, and the fluid is incompressible. 

When you apply pressure to the fluid, we assume all the pressure is transferred to the system parts. Then it pushes the energy from one point to another. 

How a Hydraulic System Works

Hydraulic systems work by applying force at one point and then transmitting the energy to another through a fluid. In the system, we assume the fluid is in-compressible. It means that the fluid, which is usually an oil, should maintain the volume even when the pressure is applied. 

You can arrange all the piping elements to achieve specific results. Follow the installation manual or hire an expert to set the system for you. You can multiply the force from the initial force applied. It helps you to achieve more work from the system.

Functions of a Hydraulic Flow Control Valve 

Hydraulic ram valves are useful in controlling the hydraulic system—the hydraulic system in various industries. You can find them in excavators and other lifting materials. 

Vital Parts in a Hydraulic System

All hydraulic systems have the same components. What differs is the complexity of their arrangements. The parts are explained below.

Hydraulic Pump

This part pushes the hydraulic fluid from the tank to the rest of the system. The pump creates a vacuum at the inlet. Then, the liquid is pushed out of the reservoir into the pump. The pump then forces the fluid to the outlet into the rest of the system. There are different types of pumps as below. 

Variable Displacement Pumps

These pumps work with varying flow rates. They can change the pressure of the fluid at the outlet. Also, they are the most expensive hydraulic pumps in the market. You can work with them in a series of complex tools. 

Fixed Displacement Pumps

The exact amount of fluid moves with every pump stroke. These pumps work with a uniform flow rate. They work with one tool at a time. Also, they give consistent results over a long time.  

Hand Hydraulic Pump

These are the most straightforward hydraulic pumps. They perform easy tasks, and you operate them manually.


These are the hollow structures within the hydraulic system. They carry the hydraulic fluid from one point to another. They have to be strong enough to withstand the pumping pressure. 

Reservoir Oil Tank

It’s the tank that holds the hydraulic fluid. It’s hardy and robust to withstand pumping pressure and vacuuming. The tank also protects the fluid from contamination. When the liquid is clean, the hydraulic system will work seamlessly. 


This is the part that changes the hydraulic energy into mechanical energy. It helps the hydraulic system to accomplish a task. The actuator can be in the form of a hydraulic cylinder. This type Creates a linear movement; The other type is a hydraulic motor. It creates a rotation and twisting force. 


The flow control valves control the flow rate, pressure, and direction of fluid flow. There are various types of valves. They depend on the role they play in the hydraulic system. There are several types of flow control valves. They include butterfly, check, ball, bypass relief, diverter, needle, pilot-operated, regulating, proportional, and directional. However, all the types are under three classes as below. 

Flow Control Valve

These are the flow control valves that regulate the flow rate of a fluid. You achieve this by increasing or reducing the flow diameter. Thus, the flow control valve acts as a gate. It opens and closes according to how you set it. 

You’ll find flow control valves in motors, cylinders, and actuators. When you reduce the flow rate with these valves, you reduce the speed of operation in systems. The typical flow control valve in a home is the water faucet. You can gauge flow rate as mass flow rate, volumetric flow rate, or weight flow rate. The flow control valve will work well with all. 

Pressure Control Valve

As the name guest, they regulate the pressure of fluid within a flow system. The valve keeps the pressure at the desired levels. It controls the pressure from the inlet to match the pressure requirement at the outlet. These valves help prevent leaks that happen due to pressure increases. Also, the popes and caps will remain intact due to controlled pressure. 

Direction Control Valve

These are flow valves that can function in both directions. If you need to change the flow direction, you will not realign the valve. It will work just well. The valve also can stop, start, and change the direction of flow.

A check valve is the simplest directional flow control valve. It allows the fluid to flow in one direction. It closes when the fluid flow reverses. Thus, it works as a valve to guide the flow in one direction. Complex direction control valves have more than one port. They allow fluids to shift through various valve ports. 


You need to keep the hydraulic oil clean. A filter plays the role of protecting the hydraulic system from contamination. It keeps the system safe and effective. 

When the hydraulic oil gets in contact with a contaminant, it loses the in-compressible trait. Thus, the fluids lose volume when some pressure is exerted. Ir makes the system harder to use. 

If you run a hydraulic system without a filter, you will use more money on maintenance. Also, you will need to replace some parts more frequently. The flow control will be unreliable. 

Power Source

Every hydraulic system needs a power source. You may use an electric motor or another power source available. 

Servicing and Maintenance

All flow control valves need maintenance. You can consult with your supplier to know the appropriate wait duration before starting servicing your flow controllers. 

Seek services from reputable service providers. If your supplier is within your town, they are the best to offer service. 


Flow control valves are sensitive. They can lead to pressure loss if one of the components is loose. This can, in turn, affect the performance of the valve. 

Basic control valves are not very effective. You can experience a change in the flow direction when the valve is in a static position. This can happen due to the change in heat levels, pressure, and flow rate. 


Flow control is easy when you have a suitable valve. Select a value that will meet your firm’s needs. Also, check the budget and your accuracy needs and adjust accordingly. There are plenty of flow control valves you can select from. The design consideration depends on the type of fluid you use. Some valves work well with gases, while others are exclusively for liquids. Also, different valves can withstand different levels of pressure. 

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