Solenoid valves are widely used in our production processes, and during maintenance, we have encountered numerous issues related to these valves. Over time, we have dealt with various failures and accumulated considerable experience in troubleshooting solenoid
Valve problems. Compared to other instrument control faults, handling solenoid valve issues is generally less complex. Today, I’d like to share my insights on this topic and look forward to learning from your experiences as well, so that we can collectively improve our skills.
To start with, let’s briefly understand what a solenoid valve is. A solenoid valve consists of a solenoid coil and a core, along with one or more holes in the valve body. When the coil is energized or de-energized, the movement of the magnetic core controls whether fluid passes through the valve or is shut off, thus changing the direction of the fluid flow. The electromagnetic components include a fixed iron core, a movable iron core, and a coil. The valve body typically contains a spool, a sliding sleeve, and a spring base. The solenoid coil is mounted directly onto the valve body, which is enclosed in a sealed housing, forming a compact unit.
In our production, we commonly use two-way, four-way, and five-way solenoid valves. Let me explain the meaning of the first two: a two-way solenoid valve controls the on/off state when it is energized or de-energized. In our oxygen meter instrument control system, three-way solenoid valves are the most frequently used. They are employed to connect or cut off the gas source, thereby switching the pneumatic control diaphragm's air path.
The structure of a three-way solenoid valve includes a valve body, valve cover, electromagnetic component, spring, and sealing mechanism. A sealing block at the bottom of the moving iron core closes the air inlet using spring pressure. When the coil is energized, the electromagnet pulls the moving core upward, lifting the sealing block and allowing airflow to enter the diaphragm head. When power is lost, the electromagnet releases, and the spring pushes the moving core down, opening the exhaust port and closing the intake, causing the diaphragm to return to its original position.
In our oxygen plant, such valves are used for emergency shutdowns of turbo-expander inlet regulators. Four-way solenoid valves also have many applications in our process. Their working principle involves current flowing through the coil, generating a magnetic field that pulls the fixed core and moves the plunger, changing the fluid direction. When the coil is de-energized, the spring pushes the plunger back, restoring the original flow path.
In our oxygen production, the molecular sieve switching system uses a two-position four-way solenoid valve to control the forced valve. Air is supplied to both ends of the piston, enabling precise control over the valve’s opening and closing.
Common solenoid valve failures can significantly affect the operation of switching and control valves. Here are some typical issues and solutions:
1. **Loose connections or missing threads**: Check if the valve is properly tightened. If the thread is missing, reattach it securely.
2. **Burned-out coil**: Use a multimeter to test the coil. If it shows an open circuit, the coil is damaged. This may be due to moisture, poor insulation, or excessive current. Prevent water ingress and ensure proper coil design.
3. **Stuck valve**: Due to small gaps (less than 0.008mm) between the sleeve and spool, impurities or lack of lubrication can cause sticking. You can try gently tapping the valve with a thin wire to free it. For a permanent solution, disassemble the valve, clean the spool and sleeve with CCI4, and ensure proper lubrication.
4. **Leakage**: This can result from damaged seals or worn slide valves. Inspect the gaskets and check for wear. If necessary, replace them and ensure the oil mist hole is clear and adequately lubricated.
When dealing with solenoid valve failures in the switching system, choose an appropriate time, such as during a power-off period. If not during a switching window, the system can be temporarily suspended to handle the issue safely. Always remain calm and methodical in your approach.
Automotive Series
Advantages of Casting Process:
1: Suitable for complicated structures.
2: Customized, made to customer's drawing or prototype.
3: Casting provides Precise shape, less material machining.
4: Wide weight variation allowed,from 1kg to 40kgs.
5: Wide range of material spec can be selected:
GG450,GG500,GG700,ASTM 65-45-12, SIMO Alloy Iron
6: Parts can be used for different industries, Auto Exhaust Pipe, Hydraulic, Agricultural Machinery Parts
7: High temperature resistant
Certificastes and Documents Provided:
- PPAP
- CPK
- SPC
- MAS
- Non-Destructive Report, UT,MPT
Packaging and Transport : Plywood Case packing
1) Standard plywood case for outside packing.
2) Rusty proof oil or liquid applied for each part.
3) Parts are segerated one by one with plastic plate.
Delivery Terms:
- FOB
- DDU
- DDA
- CIF
- CNF
Our Services
1: MOQ: 5 pcs
2: Sampling Time: 30 days including moulding
3: Within 24 hours response for each email
4: Flexible payment terms provided
5: Weekly project update
Car Exhaust Part,Car Exhaust Pipe Part,Automotive Exhaust Part,Car Casting Exhaust Part
J.B Machinery (Ningbo) Co., Ltd. , https://www.jbcastings.com