Product introduction of Danfoss ICLX32-40 (DN50-65) ICLX100-150 return solenoid valve

The ICLX two-step opening solenoid valve belongs to one of the ICV product series. The ICLX servo valve is suitable for use in the suction line under high pressure conditions to achieve safe opening of the valve. Its typical application is as a solenoid valve for the return air pipe of an evaporator that needs hot gas to defrost in large industrial refrigeration systems. The ICLX valve is configured in the two-step opening mode at the factory. This valve can be set to open in one step, the setting method is very simple. In the two-step mode, the first step is to turn on about 10% of the flow after the first solenoid valve is energized. The second step is to open automatically when the valve differential pressure drops to approximately 1.25 bar (18 psi). The ICLX valve is composed of five main components: valve body, bonnet, functional module and 2 solenoid pilot valves. The valve cover and function module of ICLX 32-150 have been assembled at the factory.

The working principle of Danfoss ICLX32-40 (DN50-65) ICLX100-150 return solenoid valve

The ICLX valve is used as a shut-off valve in the suction line, which opens after the end of hot gas defrost. It is a valve controlled by a pilot valve and works under the action of an external pilot pressure source. In other words, even if the internal pressure difference (Pd) is zero, the valve will still work. The main goal of ICLX valves is to reduce Pd, so it is particularly suitable for applications sensitive to differential pressure.
Although Pd is controlled at a low level, it still has a certain value, so the size of the valve must be considered when selecting the valve. For the influence of this factor, please refer to the “Selection of ICLX Valve” chapter. The main valve is equipped with two solenoid pilot valves and an external pilot joint. The external pilot line must be connected to the system pressure (p2), which is at least 1.5 bar (20 psi) higher than the valve inlet pressure (p1). The differential pressure between the external pilot pressure and the valve inlet pressure determines the maximum opening differential pressure (MOPD) of ICLX.

When the coils of the EVM solenoid pilot valve in position 1 and position 2 are energized, ICLX remains open.
When the coils of the EVM solenoid pilot valve in position 1 and position 2 are de-energized, ICLX closes and remains closed.
After the solenoid pilot valve (Position 1) is opened, an external pilot pressure (p2) is allowed to act on the bottom of the servo piston, thereby activating the first opening function and circulating about 10% of the valve capacity. At the same time, the deflation spring will be compressed. This will make the inlet pressure (p1) and outlet pressure tend to balance. When the differential pressure of the valve drops to approximately 1.5 bar (22 psi), the spring force is sufficient to initiate the second step and fully open the valve. In this way, the high-pressure pulse caused by the valve being fully opened in the first step can be avoided. In the case where the pressure difference exceeds 1 bar (15 psi), ICLX cannot be used, otherwise the valve cannot be guaranteed to be opened in the second step.