Answer: A hazardous area is defined as an area in which there is or may develop an explosive atmosphere at concentrations requiring special precautions during the construction, installation and use of a compressed hydrogen filling station.
To hazardous areas can refer an area, classified as Zone 0, in which an explosive gas atmosphere exists continuously, for a long period of time or very often. Such zones cannot be located at hydrogen filling stations where customers and their vehicles are located.
Zone 1 is a space in which it is necessary to consider the periodic possibility of an explosive atmosphere. Such a zone is present at the vacinity of a filling station near the quick-disconnect filling connection at the moment of connecting the filling connection, during the filling process and disconnecting the filling connection. Zone 1 represents a ball with a radius of 25 centimeters.
Zone 2 is an area where there is no need to expect an explosive atmosphere to develop. But if this happens, then, most likely, it happens extremely rarely and in an extremely short time. Zone 2 extends around the dispensing device at a distance of 20 centimeters from its surface in all directions.
A non-explosive area is an area where an explosive atmosphere is not expected and therefore no special precautions need be taken during construction, installation and exploatation of a hydrogen filling station. This zone includes all other spaces available to the customer at the gas station, with the exception of the restricted areas mentioned above. However, in order to prevent dangerous situations at gas stations, there is a ban on smoking, a ban on the use of open flames and a ban on actions that can cause a fire in the area of the gas station. Prevention also includes sophisticated design principles, the use of quality materials, and rigorous functional testing in the design and construction of APT hydrogen filling stations. All of the above guarantees the safety of the station operation. Instructions for the correct operation of a hydrogen filling station should be posted in different places, and duplicated in several languages.