Where should a relief valve be located on a tank?

A relief valve should be located at the top of a tank because it is designed to release excess pressure that can build up due to thermal expansion or other factors. This placement ensures that any vapor pressure, which tends to rise to the highest point in the tank, can escape effectively. By being positioned at the top, the relief valve can alleviate pressure without obstruction, reducing the risk of tank rupture or failure.

Positioning the relief valve at the bottom or middle of the tank would not be effective, as pressure would not be adequately relieved, increasing the chance of damage or hazards. Placing it on the side may also lead to complications, as it could potentially trap pressure and create a safety risk. Therefore, the optimal placement at the top maximizes the safety and effectiveness of the relief valve's function.