Expansion devises are used in between evaporator and condenser in refrigeration system. These devices meters and regulates the flow of liquid refrigerant to an evaporator. The expansion device have following specific functions.1. To reduce the pressure of liquid refrigerant coming from condenser.2. To maintain desired pressure difference between high pressure and low pressure side of the system.3. Capacity expansion devices are used to maintain the desired rate of flow and pressure drop across the system.4. To control the flow of refrigerant according to variation of load on the evaporator. Types of expansion devices:1. Hand operated valve2. Low side float3. High side float4. Capillary tube5. Solenoid valve6. Automatic expansion valve7. Thermostatic valveHand operated valve: These are the simplest expansion device where flow of fluid (refrigerant) us controlled manually. With few exceptions, the manual or hand operated valves are obsolete and are not applied to modern systems.Low side...
