What is the minimal allowable distance above a flat horizontal surface for a fuel tank to be mounted?

The minimal allowable distance above a flat horizontal surface for a fuel tank to be mounted is 1/4 inch. This specific clearance is essential for several reasons, mainly related to safety and operational efficiency.

Maintaining this distance allows for adequate air circulation around the tank, which can help prevent the accumulation of fuel vapors or moisture that could lead to corrosion or other issues over time. Moreover, it ensures that there is sufficient space for any potential expansion of the tank or fuel as temperatures fluctuate. The clearance helps to minimize the risk of contact with the surface that could cause wear or damage, as well as prevents the tank from being submerged in any water or debris that may accumulate on the horizontal surface, which could compromise the integrity of the fuel tank.

Furthermore, regulatory standards often set minimum requirements for mounting fuel tanks to promote safe practices in handling flammable materials. This clearance requirement is a reflection of best practices in boat design and maintenance as established by organizations such as the American Boat and Yacht Council (ABYC).