The dry shell and tube evaporator is a liquid refrigerant that enters the tube from the end cover at one end of the evaporator after throttling. The end cover is cast with a partition. The refrigerant evaporates through two or more processes and absorbs the heat of the refrigerant. After that, it comes out from the same end cover and enters the compressor. If the end cover partition gasket leaks, the refrigerant will short-circuit, causing liquid return and reduced refrigeration capacity. The dry shell and tube evaporator is generally made of copper tubes. It can be made of plain tubes or inner fin tubes with longitudinal fins.