Underground storage tanks are commonly constructed in accordance with UL 1316 [1], the standard for Fiber Reinforced Underground Tanks used to store flammable and combustible liquids. UL 1316 serves as the primary guideline for the design and performance of fiberglass-reinforced plastic (FRP) underground storage tanks. It applies to single-wall, double-wall, and triple-wall configurations intended for non-pressurized, fully buried installations, commonly used for storing products such as gasoline, diesel, fuel oil, alcohols, and approved fuel blends.

This standard outlines the minimum requirements for materials, design, and structural performance, including specifications for resin systems, fiberglass reinforcement, corrosion protection, wall thickness, fittings, and manufacturing quality control. It also establishes rigorous testing criteria to ensure tanks can withstand burial conditions, including soil and traffic loads, groundwater pressure, hydrostatic forces, temperature variations, and long-term corrosion exposure. Tanks that comply with UL 1316 must be properly labeled to indicate their certification and compatibility with specific stored substances.

3D laser scanning of underground fiberglass reinforced plastic tanks is used to survey diameter compliance, compression/expansion of horizontal and vertical axes, and roundness. The data may be used to confirm that the tank was fabricated to specification and/or to confirm that the tank was installed correctly. A typical slice of a 3-D laser scan for roundness is shown in Figure 1. The data presents the reference diameter, measured diameter and tolerance – sometimes 1%. The average roundness deviation may be calculated over the length of the tank.

Read the full article at TechKnowServ.com.