01 Application and Installation of Solenoid Valves
Solenoid valves are widely used in the industrial field, especially in high-risk industries such as petroleum and chemical engineering, where the installation demand is urgent. Due to the dangerous working environment in these industries, the requirements for safety are also relatively high. In these industries, pneumatic solenoid valves, due to their fire prevention, explosion-proof and safety performance, are indispensable in industrial applications in hazardous industries and have become indispensable transmission components. They are usually installed on process pipelines, some closely attached to cylinders, while others are bypass installed using brackets.
The basic components of a pneumatic solenoid valve include electromagnetic parts and a valve body. The electromagnetic parts consist of a fixed core, a moving core and a coil, while the valve body is made up of precision components such as a spool core, a spool sleeve and a spring base. The solenoid valve mainly consists of two parts: the solenoid component and the valve body. The precision components ensure its functionality.
02 Types and Working Principles of Solenoid Valves
Two-position three-way solenoid valve
The working principle of the two-position three-way solenoid valve is: by energizing and de-energizing the coil, it controls the flow of compressed air to change the state of the valve. When the coil is energized, the electromagnet will be attracted. The charged spring seal block on the upper part of the moving iron core will close the exhaust port with the help of the spring pressure. In this way, compressed air can enter the valve cylinder from the air inlet, achieving the control of the valve. When power is lost, the electromagnetic force disappears. Under the action of the spring, the moving iron core leaves the fixed iron core and moves downward, thus opening the exhaust port and closing the intake port. As a result, the valve cylinder changes its state.
Two-position four-way and five-way solenoid valves
The "two positions" mentioned here refer to the two states of power-on and power-off for the solenoid valve itself. For the controlled valve, it represents two operations: open and close. As for "how many holes", it refers to the number of air holes in the solenoid valve, which is clear at a glance. These solenoid valves work in a similar way to two-position three-way solenoid valves, with the difference lying in the number of air holes.
03 Selection of power supply
In addition, there are two power supply options for solenoid valves: 220V and 24V. In high-risk industries, 24V power supply is more common. However, both of these power supply methods have their own advantages and disadvantages. Both 220V and 24V power supply have their advantages and disadvantages. The choice should be made based on the explosion-proof requirements and transmission distance. Although using a 220V power supply is not conducive to on-site explosion-proofing, it is beneficial for long-distance transmission because high voltage can reduce the impact of voltage drop in transmission cables on solenoid valves. The use of a 24V power supply is more conducive to on-site explosion-proof, but the transmission distance is relatively short, and the impact of the voltage drop of the transmission cable on the operation of the solenoid valve needs to be considered. Therefore, when choosing a power supply, it is necessary to make a trade-off based on actual needs.
04 Diagnosis and Solution of Solenoid Valve Faults
Some common faults that may be encountered during the application of solenoid valves include: loose or fallen wiring terminals, coil burnout, and solenoid valve jamming. Common problems with solenoid valves include loose wiring, burned coils and jamming, and corresponding maintenance measures need to be taken. For the problem of loose or fallen wiring, it can be solved by re-tightening. If the coil is burned out, it is necessary to check whether the light-emitting diode on the coil head is on or off, or try inserting a metal object into the coil hole to observe whether it is attracted. If damage is confirmed, it needs to be replaced.
As for the solenoid valve getting stuck, it is usually due to the fact that the exhaust port is not equipped with a muffler, allowing impurities in the air to enter the valve, or the compressed air is impure and contains impurities, water, oil and other dirt. The solutions to this problem include disassembling the spool core, spool sleeve and spring base for cleaning and applying grease. At the same time, to prevent such problems from happening again, a muffler should be installed at the exhaust port of the solenoid valve, and an air filter pressure reducing valve should be added at the front end of the intake to purify the compressed air. In addition, the air filter pressure reducing valve can also be used for pressure regulation to ensure that the working pressure of the cylinder is within an appropriate range, thereby protecting the valve and controlling the opening and closing speed.
