As many of you know, I stopped using 1910.106, OSHA’s flammable liquid standard, nearly 20 years ago. Instead, I use the Internation Fire Code for all my Hazardous Materials, especially flammable liquids and gases. This code provides some excellent design/requirements for unloading flammable liquids, which can be one of the HIGHEST RISKS on a plant site.
Emphasis by me
5704.2.9.7.5.2 Determination of available tank capacity.
The filling procedure shall require the person filling the tank to determine the gallonage (literage) required to fill it to 90 percent of capacity BEFORE commencing the fill operation.
As an additional safety measure, the filling procedure is to include a requirement that the operator determine the gallonage (literage) required to fill the tank to 90-percent capacity before commencing the operation.
5704.2.9.7.6 Fill pipe connections.
The fill pipe shall be provided with a means for making a direct connection to the tank vehicle’s fuel delivery hose so that the delivery of fuel is not exposed to the open air during the filling operation. Where any portion of the fill pipe exterior to the tank extends below the level of the top of the tank, a check valve shall be installed in the fill pipe not more than 12 inches (305 mm) from the fill hose connection.
The filling operation could create a vapor-air mixture above the LFL. The fill hose is to be tight fitting to reduce the potential for the flammable or combustible liquid to be exposed to air.
5704.2.9.7.7 Spill containers.
A spill container having a capacity of not less than 5 gallons (19 L) shall be provided for each fill connection. For tanks with a top fill connection, spill containers shall be noncombustible and shall be fixed to the tank and equipped with a manual drain valve that drains into the primary tank. For tanks with a remote fill connection, a portable spill container shall be allowed.
To control spillage during filling, a spill container is to be provided for each above-ground tank. The spill container must have a top fill connection, be noncombustible and be permanently fixed to the tank. This spill container is to drain directly into the aboveground tank. A remote fill connection can use a portable spill container.