FTPI RP 2007-2 : 2014

This field test procedure is designed to test the integrity of the dry annular space of double or triple wall underground fiberglass storage tanks. The test procedure draws a vacuum on the annular space and monitors for vacuum decay over a prescribed period of time. The vacuum test time depends on the volume of the annular space and the installation site conditions. The underground fiberglass tank may contain any level of liquid (e. g. product or water) and liquid may be removed or added at any time during the annular space test. However, product deliveries should be avoided if possible. If a delivery occurs during the test and the vacuum experiences a significant change, the test should be restarted.