Where must the storage tank be vented?

The most appropriate answer to the question regarding where a storage tank must be vented is to the atmosphere. Venting a storage tank to the atmosphere allows for the release of vapors, which is essential to prevent pressure buildup within the tank. This function is crucial for safety, as excessive pressure can lead to catastrophic failures, leaks, or even explosions.

Venting to the atmosphere ensures that gases generated inside the tank, whether from fuel evaporation or other processes, can disperse safely into the open air. This is critical for systems containing fuels or other volatile substances, where managing vapor pressure is a vital aspect of safe operation.

In many cases, regulations and best practices dictate that venting must be done in a way that minimizes hazards, such as preventing vapors from igniting. Venting options like venting to a dedicated compartment or indoors pose significant risks and are typically against safety regulations because they can create hazardous conditions, such as explosive atmospheres or toxic gas buildup in enclosed spaces. Thus, venting to the atmosphere is the preferred and often required option for tank safety.