10 Minutes to Quickly Understand the 5 Key Valves of the Air Compressors

Air compressors have different valves, and each valve has a different function and purpose. If you have a thorough understanding of the design function and working principle of each valve, it will be better for the future inspection and maintenance of air compressors. Here Chengdu Pudding Mechatronic Co. CPMC provide the critical advice to help you understand the common faults and principles of the 5 key valves in air compressor system.

Because the valve has a certain service life, when the use time reaches the limit that the valve can withstand, it is inevitable that the valve will fail, so how should we avoid it?

The five major valve parts of the fuel injection air compressor are: Unloading valve, Min pressure valve, Oil stop valve, Check valve (One way valve) and Thermostatic valve. Let’s interpret each valve function and troubleshooting one by one.

A. Unloading valve function

When the gas consumption changes, the intake valve adjusts the opening degree of the valve body through the control system to match the gas consumption. It is a valve that controls the air compressor to produce and not produce gas.

Common corresponding faults:

1. The air compressor is not loaded. This fault control panel displays (no alarm; the operating state is loaded, the fuel injection pressure is very small or 0’; the machine head outlet temperature is less than 70C° to determine the machine
The group is not loaded. The problem lies in the unloading valve body, control circuit, loading and unloading solenoid valve and other parts, which need to be checked and eliminated one by one.

2. The air compressor is not unloaded. This fault control panel displays (no alarm; operating status’unloading; fuel injection pressure rise>4; head outlet temperature>80°C) to determine the machine
The group is not uninstalled. The problem lies in the unloading valve body, control circuit, loading and unloading solenoid valve, etc., which need to be checked and eliminated one by one.

B. Minimum pressure valve

Function:
1. The opening pressure of the minimum pressure valve is about 4 bar, to ensure that the pressure in the cylinder is not lower than this minimum pressure when the air is output, so as to avoid excessive air flow rate causing oil and gas separation.
The separation effect of the separator is reduced.

2. When the machine starts, a certain pressure is established in the oil cylinder to ensure the circulation of lubricating oil and provide the initial control pressure for the control loop.

3. It has the function of a one-way valve to prevent the compressed air of the pipe network from returning to the inside of the machine.

Common corresponding faults

1. The safety valve of the oil cylinder sprays air during operation. This failure is because the minimum pressure valve is not opened, which causes the pressure in the cylinder to be too high, and the safety valve is pressure-relief protection.

2. Motor overload protection occurs when the computer is running. This fault is that the minimum pressure valve is not opened, which causes the pressure in the cylinder to be too high, the main motor load increases, the current increases, and the thermal relay. The protector shuts down.

3. The air compressor failed to start. This failure is that the minimum pressure valve is not closed tightly, causing the compressed air of the pipe network to return, causing a certain pressure in the oil cylinder, causing the unit to fail to start.
verb: move. When the air compressor is started, when the control computer detects a certain pressure in the cylinder, the unit will not be able to start.

4. The oil pressure is too high when the air compressor is unloaded. This fault is that the minimum pressure valve is not closed tightly. When the unit is unloaded, the compressed air of the pipe network will flow back, which will increase the pressure in the cylinder and cause the oil pressure to rise.
High, the energy consumption of the unit increases.

C. Oil cut-off valve

Function:
After the air compressor is turned on, the oil cut-off valve is opened, and the lubricating oil that has passed through the oil filter is injected into the main engine. After the compressor is shut down, the oil cut-off valve is closed to cut off the oil supply.

Common corresponding faults:

1. The machine will jump to high temperature quickly after starting up. This fault is that the oil cut-off valve is not opened and the lubricating oil cannot be sprayed into the machine head. The oil cut-off valve needs to be checked and maintained.

2. High temperature alarm of air compressor. This fault is that the oil cut-off valve is not fully opened, and the amount of lubricating oil sprayed into the machine head is insufficient, and the oil cut-off valve needs to be cleaned and maintained.

3. When the machine stops suddenly, the lubricating oil will be sprayed back into the air filter. This fault is caused by the lagging or lax closing of the shutoff valve when the unit suddenly shuts down. The shutoff valve needs to be cleaned and maintained.

D. Check valve

Function:
The oil and gas mixture compressed by the main engine is unidirectionally delivered to the oil cylinder to prevent the oil and gas mixture in the cylinder from being sprayed back into the machine head when the machine fails suddenly, causing the rotor to reverse.

Common corresponding faults:

When the machine is stopped, the oil and gas mixture is sprayed back into the air filter. This fault is caused by the one-way valve stuck or damaged when the unit suddenly shuts down, and the one-way valve needs to be cleaned and maintained.

E. Temperature control valve

Function:

1. The temperature control valve core uses the principle of thermal expansion and contraction to adjust the oil passage formed between the valve body and the shell by extending and contracting, and controls the proportion of lubricating oil entering the oil cooler to ensure rotation. The sub-temperature is within the control range.

2. The temperature control valve is an original part that controls the outlet temperature of the machine head to be no less than 68. When the oil temperature is low, the temperature control valve is closed, and the lubricating oil is directly sprayed into the machine head to be quickly heated without passing through the cooler. The temperature at the outlet of the machine head can be increased rapidly to prevent the condensed water in the compressed air from being generated in the oil cylinder.

Note:
1. The opening temperature of the thermostatic valve is generally indicated on the valve core.
2. The maximum opening temperature of the thermostatic valve is the marked temperature + 15°C.

Learn more about Air Compressors Valves. Chengdu Air Compressor dealer keeps updating informative advice for buyer’s references. If you have further questions or requirements on spare parts, air compressors or woodworking tools, please feel free to contact with CPMC.