Hydraulic control valves are integral to the performance and reliability of hydraulic systems. They regulate fluid flow, ensuring precision and efficiency in equipment operations.
When a control valve begins to fail, it can cause significant disruptions, leading to downtime, increased maintenance costs, and potential damage to other system components.
For distributors and hydraulic professionals, recognizing the early signs of valve failure is essential to maintaining system performance and minimizing downtime.
In this article, we will explore the common symptoms of a failing hydraulic control valve, potential causes, and how Vickers flow control valves can offer reliable solutions.
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Signs of a Failing Hydraulic Control Valve
Identifying valve issues early can prevent more significant problems down the line.
Here are the most common signs that a hydraulic control valve may be malfunctioning:
- Valve will not shift positions.
- Erratic or Inconsistent Operation - Sudden surges or drops in hydraulic pressure.
- Irregular flow rates causing uneven movement in actuators.
- Leaking Hydraulic Fluid - Visible leaks around the valve housing or fittings.
- Loss of system pressure due to internal or external leaks.
- Reduced System Performance - Sluggish operation of hydraulic equipment.
- Inability to achieve desired flow or pressure levels.
- Unusual Noises - Hissing, whistling, or knocking sounds indicating internal wear or contamination.
- Overheating - Excessive heat in the valve or connected components due to fluid bypass or restricted flow.
- Physical Damage - Visible cracks, corrosion, or wear on the valve body or internal components.
Causes of Hydraulic Control Valve Failures
Understanding what causes valve failures can help prevent future issues. Here are the most common culprits:
- Contaminated Hydraulic Fluid - Dirt, metal particles, or degraded oil can lead to wear, clogging, and improper sealing.
- Improper Installation or Maintenance - Misaligned connections, overtightened fittings, or lack of regular inspection can contribute to valve damage.
- Excessive Pressure or Flow - Operating a valve outside its rated capacity can cause internal damage and leaks.
- Normal Wear and Tear - Over time, seals, spools, and other components wear down, leading to reduced performance and efficiency.
Troubleshooting a Faulty Valve
When you suspect a control valve issue, follow these troubleshooting steps:
- Inspect for Leaks: Check around the valve body, fittings, and seals for visible signs of fluid leakage.
- Test System Pressure: Use a pressure gauge to verify if the system is operating within the recommended range.
- Check for Contamination: Sample the hydraulic fluid and inspect for particles or discoloration.
- Evaluate Actuator Performance: Observe if connected cylinders or motors are moving as expected.
- Consult Technical Resources: Refer to the valve’s technical manual for specific troubleshooting guidance.
- Measure & compare current (Amperage) vs manufacturers specifications.
- If manually operated, confirm the hand actuation is functional.
If these steps confirm that the valve is the issue, replacing it with a high-quality option, like a Vickers flow control valve, is often the best course of action.
Hydraulic Flow Control Valves 101
Hydraulic flow control valves do what they say: They control flow rates in hydraulic circuits, with an end goal of controlling speed elsewhere in a fluid power system.
In hydraulic systems, these valves are used to regulate flow rates to actuators, such as motors and cylinders, and with it the speed of those components.
Flow rate also determines the rate of energy transfer at any given pressure. A common physics concept is used to determine this transfer:
Actuator force x distance traveled = work done on load
This equation shows that the actuator force, multiplied by the distance through which it moves (stroke), equals the work done on the load. The energy transferred must also equal the work done, and speed determines the energy transferred.
In other words, regulating speed is the primary function of flow control valves because:
- Energy transfer must equal work done and is determined by multiplying force times stroke.
- Speed determines the amount of energy transferred.
- Flow rates determine the speed of an actuator.
Why Vickers is a Good Bet
There are a variety of flow control valve designs, each intended for specific applications. The most common types include ball, diaphragm, needle, and butterfly.
HPS has the largest in-stock availability of obsolete, discontinued, long-lead and hard-to-find products and control valves are no exception.
And, of its more than 2 million hydraulic parts on the shelf, Vickers stands out as:
- A well-known global manufacturer of hydraulic products.
- A product line capable of many different applications and markets.
- An industry leader in low-speed, high-torque (LSHT) hydraulic motor technology.
- A high-performance and long-lasting product line ideal for remanufacturing.
HPS offers a variety of quality fluid power products, and we’re confident that Vickers hydraulics are sure to be a long-lasting and reliable fit for end-users who demand dependability and performance.
Of HPS’s more than 2 million hydraulic parts on the shelf, Vickers products continue to lead the way with high performance, dependability, and flexibility that stand the test of time. Get a quote on a product now by clicking here.
We all know distributors are a valuable resource for end-users of fluid power products, often providing local, on-site, customer support. Closer to end-users than manufacturers, their customers should be able to rely on that local support.
To help provide that support, knowledge about the products they sell helps to meet the support needs of their customers/end-users. Fluid power distributors can take what they learn about customers’ specific pumps, motors, and valves, and put that knowledge to use for their clients. If you are a distributor and your end-users can benefit from knowing more about the products you offer, this article is for you.
As pumps and motors are responsible for supplying power and energy within a hydraulic system, valves are the mechanical devices used to control that power by regulating the flow of fluid.
They can be used to redirect pressurized fluid, control the level of flow to a certain area, or completely close a line.
Although there are dozens of varieties that all serve different purposes, in this article, we will focus on these three major types of hydraulic valves:
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- Pressure Control Valves
- Flow Control Valves
- Directional Control Valves
Each type has its own functions within a fluid power system and applications in which they provide the ideal result. Each hydraulics brand provides various configuration choices based on valve type. Acquainting yourself with these differences can be useful when offering clients support on valve-related issues.
If you are looking to provide guidance when your customer has a question or a problem, or if they’re asking you to consult on purchase decisions more confidently, we recommend starting with basic knowledge of how pressure control valves, flow control valves, and directional flow valves operate.
Pressure Control Valves
Hydraulic pressure control valves are used to regulate the fluid pressure that is passing through hydraulic systems and prevent rises in pressure that may result in system problems. They are also used to maintain a set pressure in a part of a hydraulic circuit.
Different types of pressure control valves include:
- Pressure relief valves
- Pressure Reducing valves
- Sequence valves
- Counterbalance valves
Hydraulic relief valves limit system pressure to protect components. The valves also limit the hydraulic system’s maximum output force and control the amount of heat generated by balancing the hydraulic force with an adjustable spring force.
Pressure reducing valves are used to balance hydraulic circuit pressure with pressure in the main circuit. When the outlet pressure reaches a preset level, the valve opens, a piston moves to release pressure, and it keeps the outlet pressure constant.
Sequence valves are used to control the sequential operation of actuators. If the inlet pressure exceeds a preset level, they add pressure to the outlet side. A check valve allows for this directional control.
Counterbalance valves are used to maintain hydraulic pressure or load backpressure on a cylinder by releasing flow levels to keep pressure constant. Like sequence valves, they use a check valve to provide a counterbalance of flow, lifting the cylinder up to freely pass.
Flow Control Valves
Hydraulic flow control valves do what they say: They control flow rates in hydraulic circuits, with an end goal of controlling speed elsewhere in a fluid power system.
In hydraulic systems, these valves are used to regulate flow rates to actuators, such as motors and cylinders, and with it the speed of those components.
Flow rate also determines rate of energy transfer at any given pressure. A common physics concept is used to determine this transfer:
Actuator force x distance traveled = work done on load
This equation shows that the actuator force, multiplied by the distance through which it moves (stroke), equals the work done on the load. The energy transferred must also equal the work done, and speed determines the energy transferred.
In other words, regulating speed is the primary function of flow control valves because:
Energy transfer must equal work done, and is determined by multiplying force times stroke
Speed determines the amount of energy transferred
Flow rates determine the speed of an actuator
There are a variety of flow control valve designs, each intended for specific applications. The most common types include ball, diaphragm, needle, and butterfly.
Directional Control Valves
Directional control valves have three main functions: to stop fluid flow, to allow fluid flow, or to change direction of fluid flow between hydraulic cylinders and motors.
They typically consist of a sliding spool inside a cylinder, which restricts or permits fluid flow to control the fluid path. They can also consist as a poppet to control flow, which works in the same way.
Directional control valves can stop the flow suddenly and are sometimes referred to as either “switching” or “bang-bang” valves for the sound they make when operating.
There are two other types of directional valves that can control fluid flow in more complicated hydraulics systems:
- Proportional valves -Allow infinite positioning of spools and flow volumes for more complex circuits
- Servo valves - Operate with high accuracy, repeatability, low hysteresis, and high frequency response for sophisticated loop systems (and are often more expensive than proportional valves)
More Product Knowledge to Steer Satisfied Customers
In summary, hydraulic valves provide the control needed to keep hydraulic systems working. They act as the steering wheel to guide the moving parts of a functional hydraulics system.
And whether they are used to control flow by redirecting pressurized fluid (pressure control valves), controlling the level of flow and speed (flow control valves), or completely stopping the directional flow (directional control valves), knowing about different types of valves and their intended function can be a great tool to help you support your customer’s individual needs.
The company is the world’s best hydraulic system relief valve supplier. We are your one-stop shop for all needs. Our staff are highly-specialized and will help you find the product you need.
Knowing the basics of different components and how they work is the key to offering this guidance, and to provide a valuable resource to your customers / end users.