What is the gauge pressure limit for emergency venting conditions in tanks?

In the context of emergency venting conditions for fuel tanks, the gauge pressure limit is critical for ensuring safety and preventing overpressure scenarios that could lead to tank failures or hazardous situations. A limit of 2.5 PSI is established to provide a balance between allowing for some build-up of pressure that can occur due to thermal expansion of the contents or other factors, and ensuring that this pressure does not exceed safe operational levels.

Maintaining this pressure limit helps to ensure that any emergency venting systems are effective and that they function properly under expected conditions. By setting this limit, the regulations aim to reduce the risk of ruptures, leaks, or other failures that could occur if pressures were allowed to rise unchecked.

The choice of 2.5 PSI specifically is based on industry standards and safety practices that have been developed to protect both the tank and the environment. Lower limits might not provide sufficient operational freedom for the tank’s pressures and could lead to more frequent activations of the venting system, whereas higher limits could compromise tank integrity.