How should a tank be prepared after being purged of vapors?

To ensure safety after purging a tank of vapors, it is crucial to prevent the accumulation of any residual vapors that could pose a risk of explosion or fire. Sealing the tank while allowing for ventilation through a small hole is a prudent approach. This method ensures that any potential gas buildup can safely escape, while also minimizing the potential for outside contamination or adverse weather elements to enter the tank.

Leaving the tank open for ventilation could expose it to environmental factors and increase the risk of pollutants entering the tank or contaminants affecting future use. Filling the tank with water, while sometimes considered for certain applications, may not always be practical or necessary in all circumstances, especially if a long-term storage solution is intended. Immediate removal of the tank from the site, while sometimes a solution, is not always feasible and does not address the continued need for ventilation in the short term after purging. Therefore, sealing the tank with a small vent hole is the best option to manage safety and environmental concerns effectively.