Types of electromagnetic Valves
Three types of electromagnetic valves are in common use:
- Two-way valve that controls the flow of the refrigerant through a single line.
- Three-way valve to the inlet that is shared by two opposite holes. It controls the flow of refrigerant in two different lines. Cm. Fig. 5-39.
- The four-way reversing valve is used on heat pumps.
Solenoid valves can be activated by a thermostat. These valves are designed to control the temperature of the refrigerator or room. Three-way valves are used mainly for commercial refrigeration. They can be used to control two separate refrigerant circuits to defrost, two-temperature evaporators and other
In the three-way valve is shown in Fig. 5-39, the opening is a General opening and is never closed. As solenoid is de-energized, the following occurs: weight solenoid plunger keeps the valve against the lower seat. Tyres force top source also keeps the valve categorically opposed to below the seat. This action closes the port total port and opens a port C.
When the electrical circuit is closed, the electromagnetic becomes energy.
Piston with two valves attached to it will move in the opposite direction. This action opens a port B to the total port A. It closes port total port.
Four-way solenoid valves are often called reversing valves. Four-way solenoid valves are used mainly for heat pumps. They control loop either for heating or cooling, as needed. When the solenoid is de-energized, the valve closes several ports. This opens up other reverse flow of the refrigerant in the condenser and the evaporator. The heat pump will then become the cooling system. When the solenoid valve is becoming energetic, four-way valve stem drawn up. The heat pump system is a heating system again.
For large commercial applications, it is desirable to use pilot operated solenoid valve. These valves, solenoid operates a pilot mechanism. Pressure in the line work in a piston agreement. This causes the opening and closing of the main control valve.
Figure 5-40 - business card pilot solenoid valve is controlled. When enabled, a solenoid actuator will be pulled from the saddle. The pressure in the diaphragm spring area leaves the cylinder, and aperture will move up. The movement of the diaphragm control opens pilot port.
When the solenoid valve is de-energized, the piston returns to its place. Inlet pressure passes through a small hole (pilot canal) and creates the pressure in the diaphragm spring area. In the spring then closes the pilot canal.
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