For conducting a pre-installation air test of an FRP tank under 12 feet in diameter, what should the pressure be?

The appropriate pressure for conducting a pre-installation air test of a fiberglass reinforced plastic (FRP) tank that measures under 12 feet in diameter is indeed 3 pounds of air pressure. This specific pressure level is established based on industry standards to ensure the tank's structural integrity and to verify the absence of leaks prior to installation.

Conducting the test at 3 pounds allows for a thorough examination of the tank's seams, joints, and overall construction. It ensures that the material can withstand the operational pressures it will encounter once in use. The pressure is carefully regulated; too low could result in insufficient testing, while too high could risk damaging the tank or leading to false results. Therefore, adhering to a 3-pound air pressure is a reliable method for confirming the readiness and safety of the installation.