Access valve is mainly composed of components such as a nylon valve needle, valve seat, limit ring and housing. Its internal structure may vary depending on the type, such as a ball valve or a needle valve. On the outer surface of the check valve, the direction of the refrigerant flow is usually marked with an arrow to ensure that it is not connected in reverse during installation.

In the refrigeration system of a refrigerator, the main function of the access valve is to prevent the high-temperature and high-pressure vapor inside the compressor from flowing back into the evaporator when it stops, which could cause the evaporator to heat up and thus reduce the refrigeration efficiency. By connecting access valve, the high and low pressure inside the refrigeration system can be quickly balanced when the compressor stops, facilitating a restart.