How do I check a hydraulic solenoid valve in order to see whether it is OK or faulty?

hydraulic solenoid valve

If you are related to hardware and tools, you must know about Hydraulics and solenoid valves in it. If you don’t know, it is a system of Hydraulics used for changing the course, opening, and closing off the fluid flow in the machine with the help of a solenoid-controlled valve. The solenoid is an electric coil turned around a ferromagnetic core, and the valve is operated with that solenoid. Ports are the different chambers of the valve that helps in various operations. Unfortunately, they can be faulty sometimes and show some unexpected behaviors, so few points help in knowing whether the Hydraulic Solenoid valve is Faulty or not! In this article, we have given a brief explanation of the 

Why do Valves Need testing?

hydraulic solenoid valve 1
Image Source: Mini Hydraulic Power Packs & Hydraulic Power Units

Solenoid valves are susceptible parts, and a slight impurity can cause damage to it. However, they are crucial to the hydraulic machines as it conducts all the operations with the help of electric signals. The solenoid valves constantly work in open humid, and gas-exposed areas, so there is a high chance that they can get corroded and layers of different minerals get stuck on the surface, causing leakages. There are many cases where hydraulic systems have exploded or ruptured due to the cheap and low maintenance of the solenoid valves. So it is crucial to maintain and test the Solenoid valves for any leaks and faults.  

How frequently should the solenoid coil be tested?

There is no definitive answer as to how frequently the solenoid coil should be tested. However, it is generally recommended that the coil be inspected and tested at least every 6 months or whenever there is a noticeable change in performance. The Hydraulic solenoid valves are used under much pressure and have high wear and tear in shorter times due to high load and pressure. Therefore, it should be tested and maintained according to the stress and load given on it. Usually, it should be tested every two months to three years based on the application.  

What is a Spool in Hydraulic Solenoid Valve?

A spool is a component of a hydraulic solenoid valve. It’s a metal or plastic ring that’s inserted into the valve body and functions as an actuator. When the pressure in the system rises, the spool shrinks, moving the valve in its opening direction. This allows the hydraulic fluid to flow into and out of the valve. In a Hydraulic solenoid valve, a spool is a coil packed in a sealed cylindrical case. They have solenoids on two sides, making them a valve that helps in the operation of hydraulic machines. It has inlets for current and electric signals, which transmit themselves to the valve and makes the Hydraulics operational.

The features of a Spool in Hydraulic Solenoid Valve?

A spool in a hydraulic solenoid valve is a component that helps control the flow of hydraulic fluid. This type of valve has many features that make it an effective tool for controlling the movement of fluids. Some key features of a spool in a hydraulic solenoid valve are its ability to rotate and its ability to hold a certain amount of fluid. This allows the spool to limit the amount of fluid that flows through the valve at any given time. The rotating feature also helps control the direction of fluid flow, which is important for valves that use pressurized fluid to move objects or substances. The holding capacity of the spool also helps keep the pressure inside the valve, which prevents damage to equipment or people when the valve is used incorrectly.

Here are some ways of checking the solenoid valve to see if it is faulty or not.

Solenoid Valve sealing

The leaking of the valve directly relies upon the tightness of the sealing of the solenoid valve. If there is no ventilation and the valve is in casual use, there will be no air or fluid leakage. However, during a routine operation, if there is a sound of exhaust in the valve, there must be a leakage of air in the solenoid valve. More considerable leakages can be easily found by this method, but it is insufficient for more minor leakages; you need a different trick to find out small air leakage. You need to apply a layer of soapy water to the solenoid valve and check for an air bubble on it, the area which shows bubbles that area is affected and has air leakage. It would be best if you kept an eye on the soapy water amount you are pouring; it shouldn’t go inside the solenoid valve.

hydraulic solenoid valve 3

Image Source: Surplus Center

Switch opening and Closing Speed 

Sometimes the transmission speed of the electric signal is average, the solenoid valve operation is slow, and the electric signal speed is not followed. This is caused by the impurities present in the solenoid valve that affect the solenoid valve’s synchronization and the electric signal. In addition, the valve core resistance becomes too large to switch along with the electric signals. In this case, you need to disassemble the solenoid valve and clean it thoroughly. Then you should re-install and debug it for better performance. Only follow these steps if you are an expert, as wrong actions can damage the valve.

Reliability and sensitivity action of Solenoid valve

Hydraulic solenoid valves are reliable and sensitive machines that are used in a variety of industrial applications. The reliability of a hydraulic solenoid valve is determined by its ability to withstand the stresses and strains that it will experience during operation. In order to achieve maximum sensitivity, a hydraulic solenoid valve must be able to accurately convert the pressure that is applied to it into motion. The electric signal plays a significant role in the hydraulic solenoid valve. The operation of the valve depends on the electric signals. If the electric signal is not stable, then the solenoid valve sensitivity can be abnormal, and it can cause fluctuations in the hydraulic operation. In this case, you should look around whether the terminal is poorly connected or not, or if the current passing line is too long for causing any voltage drop. If any voltage drops or the terminals are not connected properly, then the electric signal doesn’t transmit to the solenoid valve properly, causing abnormal sensitivity. 

hydraulic solenoid valve 2
Image Source:

Abnormal behavior of the Hydraulic movement

A hydraulic solenoid valve is a type of valve that uses the pressure of the hydraulic fluid to open and close its ports. As the pressure changes, so do the size of the opening and closing port. This creates a controlled flow of fluid. Hydraulic solenoid valves are used in various industrial applications, such as pumping and water motors. They can also be found in devices that require precise control over fluid flow, such as engines, automotive transmissions, and air conditioners. If there is a fluctuation in the hydraulic operation or there is any performance drop in the hydraulic system, then you should check that the inlet voltage supply to the coil is correct or not. Improper voltage supply can fail the coil and can burn the solenoid coil. Uneven electrical strikes and surges can also damage the coil, so you should always keep an eye on that. And in case the coil is burnt or damaged, you should immediately replace the old coil and put a new one. It would be best if you also kept an eye on the internal parts of the solenoid valve as sediments and unwanted particles can damage the core of the valve, causing abnormal behavior of the hydraulic. 


Solenoid valves are widely used to replace manual valves or in the remote control. Their primary function is to facilitate either opening or closing a valve orifice and regulating the fluid flow through the valve. While the functioning of the valve is somewhat unusual and takes time to adjust to, what is more, important is to learn to troubleshoot a solenoid valve. This article contains all the necessary information about the Testing of a Hydraulic Solenoid Valve to check whether it is Ok or faulty! You will get all the answers to your questions with a brief explanation. 

Mia A Chloe
Author: Mia A Chloe

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