1. If the temperature in the warehouse changes greatly, and the air inside and outside the warehouse is completely sealed and isolated, it must be installed, such as quick freezing room and quenching room. Its working principle is that the temperature in the warehouse changes, and the air pressure also changes. When the internal and external pressure exceeds a certain value, the valve tongue in the balance window will automatically bounce off to communicate with the air outside the warehouse, and the indoor and outdoor air pressure will tend to balance and automatically close to prevent the warehouse structure from being damaged due to excessive pressure difference.
2, usually connected to 220V power supply, its role is to supply power for the electric heating of the balance window, to prevent the valve tongue part from losing its function due to low temperature conduction icing in the library.
3. It is best to install it outside the warehouse. The surrounding environment in the warehouse will cause water vapor condensation or even freezing during cold and heat exchange, which is easy to damage moving parts.