How does the delivery person know when my oil tank is full?
Each oil tank includes a fill pipe and a vent pipe. The oil drive connects the hose from the delivery truck to the fill pipe and begins pumping fuel. The vent pipe releases air from the tank while it is being filled. These pipes are generally located close to each other. The NFPA requires there to be a whistle or vent alarm on inside tanks. This whistle indicates to the delivery person when the tank is full.