What are the classes of explosion-protected hoists?

Explosion-proof hoists are classified into different levels based on their ability to withstand and prevent the ignition of explosive gases, vapors, or dust. The classification system for explosion-proof hoists is typically based on international standards, such as the ATEX directive.

Here are the common classification levels for explosion-proof hoists:

1. Zone 0: This level is the highest level of protection and is suitable for areas where explosive gas or vapor is continuously present or present for long periods. Zone 0 hoists are designed to prevent the ignition of explosive substances under normal operating conditions.

2. Zone 1: This level is suitable for areas where explosive gas or vapor is likely to be present during normal operations. Zone 1 hoists are designed to prevent the ignition of explosive substances under normal operating conditions, but they may not be continuously sealed to withstand prolonged exposure.

3. Zone 2: This level is suitable for areas where explosive gas or vapor is not likely to be present during normal operations, but may be occasionally present. Zone 2 hoists are designed to prevent the ignition of explosive substances in case of abnormal operating conditions or equipment failure.

4. Zone 20: This level is the highest level of protection for areas where explosive dust is continuously present or present for long periods. Zone 20 hoists are designed to prevent the ignition of explosive dust under normal operating conditions.

5. Zone 21: This level is suitable for areas where explosive dust is likely to be present during normal operations. Zone 21 hoists are designed to prevent the ignition of explosive dust under normal operating conditions, but they may not be continuously sealed to withstand prolonged exposure.

6. Zone 22: This level is suitable for areas where explosive dust is not likely to be present during normal operations, but may be occasionally present. Zone 22 hoists are designed to prevent the ignition of explosive dust in case of abnormal operating conditions or equipment failure.

The main difference between these levels lies in the strictness of the design and construction requirements to prevent the ignition of explosive substances. Each level is intended for different hazardous environments based on the likelihood and duration of the presence of explosive gases, vapors, or dust. It is essential to consult the relevant standards and regulations in your region when selecting an explosion-proof hoist for a specific hazardous area.