1. Function and Working Principle
Automation Control: By receiving electrical signals from the controller (PLC) (24V DC voltage), the electromagnetic coil inside the solenoid valve generates magnetic force, driving the valve core to move, thereby opening or closing the fluid passage (such as controlling the air path or oil path), achieving precise control of the key actions of the compressor.
Typical Application Scenarios:
Control the opening and closing of the intake valve, adjust the loading/unloading state of the compressor.
Control the automatic drainage of condensate water from theDischarge of pollutants valve (such as the automatic drainage valve of the oil-gas separator or storage tank) at regular intervals.
Participate in the safety protection circuit， such as quickly cutting off the relevant oil or air path in case of overpressure or overtemperature.
Advantages： Fast response (millisecond level)， high control accuracy， suitable for frequent start-stop conditions， and is the core component of the compressor's automated operation.
2. Structure and Characteristics
Core Components： Composed of an electromagnetic coil (24V DC)， valve core， valve body， spring， and sealing parts. When the coil is energized， the valve core moves to open the passage， and when it is de-energized， the spring returns to close the passage (mainly of the normally closed type， some are of the normally open type).
Material Compatibility：
The valve body mostly uses brass or stainless steel， capable of withstanding corrosion from compressed air， lubricating oil， or condensate water.
Sealing Parts： Commonly use nitrile rubber (NBR) or fluororubber (FKM) to ensure sealing performance in high temperatures (80-120℃) and pressure environments. Technical Specifications:
Working Voltage: DC 24V (suitable for the low-voltage circuit of the compressor control system, with high safety).
Working Pressure: Usually 0.5 - 1.6 MPa (designed according to the control circuit requirements).
Interface Size: Commonly G1/4, G3/8, etc. thread specifications, suitable for control pipelines of different diameters.
3. Common Faults and Maintenance
Typical Fault Manifestations:
Winding Burnout: Caused by unstable voltage, overload, or humid environment, manifested as no action of the solenoid valve, which can be detected by measuring the coil resistance with a multimeter (normal resistance is usually tens to hundreds of ohms, and after burnout, it becomes infinity).
Valve Core Stuck: Caused by impurities, oil deposits, or aging seals, manifested as the valve unable to fully open/close or having sluggish movement, which may cause abnormal compressor loading or poor sewage discharge.
Leakage: Caused by wear of the sealing components or damage to the valve body, resulting in leakage of control gas/oil, affecting the stability of system pressure.
Maintenance and Replacement Key Points:
Regular Cleaning: During compressor maintenance, check if there are impurities at the interface of the solenoid valve. If necessary, disassemble and clean the valve core (operation must be powered off).
Replacement Specifications:
It is necessary to select 24V solenoid valves of the same specification as the original factory (such as model, interface size, pressure grade), and preferentially choose Atlas Copco original accessories to ensure compatibility with the control system.
Before replacement, disconnect the power supply, release the pipeline pressure, and avoid operating with power on or spraying high-pressure media.
When installing, pay attention to the fluid flow direction (some solenoid valves have directional markings), and avoid over-tightening when tightening the interface to avoid damaging the threads.
Preventive Maintenance: In environments with high dust and humidity, it is recommended to shorten the inspection cycle and ensure the stability of the control circuit voltage to avoid over-voltage damage to the coil.
