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Maintenance of intake valve of screw air compressor

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Update time : 2021-06-17 16:05:49
Sometimes our equipment has a slightly larger current when it is unloaded, and the current of the 22KW machine is 31A when it is unloaded. It is initially suspected that the intake valve is not closed tightly, because when the air is not used, after the machine is unloaded, the pressure will slowly rise and sometimes a high-pressure alarm will be triggered! And after the shutdown, there is still some residual pressure inside the machine that cannot be discharged (in About 6 kg), causing the host to be overloaded when restarting.


The intake valve of the screw air compressor is a normally open intake valve. When the screw air compressor is not loaded, the solenoid valve is opened, and the solenoid valve is closed after the compressor is loaded. When the solenoid valve is opened, there will be a way of gas to close the intake valve, but it cannot be completely closed, and the intake space must be reserved to maintain the z* small pressure required for compressor lubrication. This pressure is generally 1.5 bar; electromagnetic After the valve is closed, the compressor will enter the normal working state until it reaches the set working pressure, which depends on the user. The intake valve has two pipes, one is vented; the other is to release the remaining air in the valve to ensure normal loading of the compressor. When unloading, the current is too large, indicating that the tank pressure is high, and the opening of the intake valve is large. Please adjust the vent screw to ensure that the tank pressure is not too high.


After the screw air compressor is stopped, the tank pressure can be completely emptied in about 60 seconds, that is, the pressure is 0, and your tank pressure is still 6bar, indicating that there is a problem with the air intake valve vent line: it may be a pipe The diameter of the road is too small; the orifice of the combined valve is too small or whether it is blocked by debris. After unloading, the pressure will rise slightly back and forth, but this is only needed for balance, and the time is very short. It will not rise to high-pressure shutdown. The high-pressure shutdown should be caused by a problem with the solenoid valve of the air compressor. Please check whether it is in good condition and whether it can work normally. Regardless of the intake valve, the tank pressure should be maintained between 1.0 and 2.0 BAR during unloading. Too high is a great waste of the energy of the screw air compressor.

Reasons and solutions for the intake valve of screw air compressor not opening

The intake valve of the screw air compressor is a component that controls the air pressure in the air storage tank. Commonly used intake valves have a rotating disc structure and a reciprocating valve plate mechanism. The disc or valve plate is used to open or close the air inlet to control Airflow entering the nose.

There are two control methods: one is a switch, when the pressure of the gas storage tank reaches the high limit set value, the air inlet is closed, and when the pressure drops to the low limit set value, the air inlet is reopened.

The other is that when the air storage tank reaches a certain pressure, the rotating disc closes the air inlet slightly under the control of the proportional valve. When the pressure of the air storage tank further increases, the air inlet is further reduced. When the pressure of the air storage tank When it is slightly reduced, the air inlet will be enlarged to stabilize the pressure within a certain range. When the pressure does not reach the adjusted pressure, the intake valve disc is fully opened, and the intake port is fully opened.

In the case of operation, what are the reasons for the closing of the intake valve of the screw air compressor? What are the solutions? Let's briefly discuss it!

1. Too much water in the control pipeline, maintain the control pipeline every day.

2. The intake valve works incorrectly. Check the cylinder, valve sleeve and other parts, and replace if necessary.

3. The air intake valve is stuck, check the intake valve, valve sleeve, or shaft, and replace if necessary.

4. The intake valve spring is broken, replace the spring

5. If the solenoid valve is faulty, repair or replace as needed, and check the wiring before replacement.

6. The reciprocating valve is damaged, repair or replace.

7. The solenoid valve wire connector is loose; check and tighten the wire terminal. 

These will cause failure of the intake valve of the screw air compressor, which should be handled with care during production and operation.