HOLT Electricians Practice Exam

What is the maximum distance from an open end of a vent that an above-ground tank in a bulk storage plant can be classified as a Class I Group Division 1 location?

1. 3 feet

2. 5 feet

3. 10 feet

4. 15 feet

The correct answer is: 5 feet

The classification of an area as a Class I Group Division 1 location is based on the potential presence of flammable gases or vapors. For above-ground tanks in bulk storage plants, this classification is particularly important to ensure safety and mitigate risks of fire or explosion. The maximum distance of 5 feet from an open end of a vent is established by industry standards, which take into account the likelihood of vapors escaping during normal operations. The presence of vapors at this distance is significant enough to warrant a Division 1 classification because it indicates that flammable concentrations could be present under normal or abnormal conditions. This standard is based on the behavior of gases and vapors, especially considering factors such as air circulation and the physical properties of the stored materials. Therefore, setting the maximum distance at 5 feet ensures adequate safety measures are in place to protect workers and the facility from potential explosive environments. Understanding this classification and its corresponding distance requirements is essential for electricians and safety personnel in the field to ensure compliance with regulations and maintain safe working conditions.