Zone 1 and Zone 2 in Ex Certification are two levels in the classification of explosive and flammable gas environments, each representing different danger levels and temporal characteristics of gas presence. Below is a detailed explanation of these two zones provided by STS:

I. Ex Zone 1

Definition: Ex Zone 1 refers to a location where explosive and flammable gas mixtures may occur during normal operation. This means that in this zone, explosive and flammable gas mixtures may arise under normal operating conditions due to various factors in production, processing, storage and other processes.

Gas Presence Duration: In Ex Zone 1, the annual duration of explosive and flammable hazardous gas presence is generally between 10 and 1000 hours. This depends on multiple factors such as production processes, equipment tightness, and ventilation conditions.

Risk Level: Since explosive and flammable gas mixtures may occur in Ex Zone 1, the risk level of this zone is relatively high. A series of Ex measures need to be taken to ensure the safety of equipment and personnel.

II. Ex Zone 2

Definition: Ex Zone 2 refers to a location where explosive and flammable gas mixtures cannot occur during normal operation; if they do occur, it is only occasional and for a short duration. This means that the occurrence of explosive and flammable gas mixtures in this zone is an abnormal phenomenon with a short duration.

Gas Presence Duration: In Ex Zone 2, the annual duration of explosive and flammable hazardous gas presence is usually less than 10 hours. This also depends on various factors such as production processes, equipment tightness, and ventilation conditions.

Risk Level: Since the possibility of explosive and flammable gas mixtures occurring in Ex Zone 2 is low and the duration is short, the risk level of this zone is relatively low. However, certain Ex measures still need to be taken to ensure the safety of equipment and personnel as a precaution.

Summary

In summary, the main differences between Ex Zone 1 and Zone 2 lie in the possibility of occurrence and duration of explosive and flammable gas mixtures. Zone 1 has a relatively higher risk level and requires stricter Ex measures; while Zone 2 has a relatively lower risk level, necessary Ex measures are still required to ensure safety. In practical applications, the division of Ex zones and corresponding Ex measures need to be determined based on specific production environments and process conditions.