Piston compressors are damaged when liquid refrigerant accidentally enters the compressor from the suction line. The refrigerant must be in a vaporous condition. Steam temperature must be higher than the evaporating liquid in the evaporator. This increase in temperature means the superheated steam. There are many devices to prevent or minimize the suction line of liquid refrigerant entering the compressor:
The battery into the suction line.
Hot gas bypass valves to move the hot gas in the suction line. There, the gas can evaporate in any liquid.
Temperature-sensing devices and solenoid valves. Heat exchangers for heating the suction line of the vapor-liquid.
Electric heaters to warm the suction line of the vapor-liquid.
Evaporator (blower coil) suction line.
Drops and slugs liquid refrigerant may travel in the suction line. This can happen if the system utilizes hot gas defrost or sudden changes in load. Many systems have the battery in the suction line.
The battery will extend Cycling interval (gas storage). Usually the puncture (suction) device for oil return. Hot gas bypass system depends on the use of a temperature sensor that is attached to the suction line. This sensor to control the solenoid valve. This valve opens when there is a danger of fluid flowing refrigerant in the compressor. Hot gas is allowed to flow into the suction line.
Electric heaters can be attached to the suction line. Temperature sensing element is included current at heating the suction line should be. Blower coil is usually managed by the temperature sensor attached to sucdon line. Suction line temperature indicates when there is risk of ingress of liquid refrigerant in the compressor. Fan coil supply will then be enabled.
The temperature of the device or pressure device should detect the presence of liquid quickly. It should include mechanisms to stop the fluid from getting on the compressor. The best sensor, thermistor. He reacts very quickly. It can be connected to the signal circuit or operating circuit. The compressor will be stopped before it can be damaged.
Industrial 
..