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Recommended Practices for the Testing and Verification of Spill,Overfill,leak Detection and Secondary Containment Equipment at UST Facilities a <br /> s <br /> For tight-wrap tanks, use the test method in this . <br /> CAUTION: Use only an air-operated vacu- section. e <br /> um source or a vacuum pump powered by 3 e <br /> an explosion-proof motor. Vacuum pumps 4.2.6 Fiberglass Tanks. Determine if the inter- <br /> with electric motors that are not explo- stitial space is a "tight-wrap' design or a "110% � <br /> sion-proof may ignite flammable vapors. containment"design.Either type of fiberglass tank <br /> If a portable air compressor Is used, it may use this test or the latest version of Fiberglass " <br /> should be located at least 20 feet away Tank&Pipe Institute's (FTPI)RP 2007,rieki Test <br /> 9 <br /> from the venturi-eduetor or outside any Protocol,for•Testing the Annular Space of Installed $� <br /> Class I, Division 1 area. <br /> •.!"` � `~ltti It g <br /> 4.2.4 Preparation. The procedures in this sec- q <br /> tion are general in nature and reflect the suggested <br /> vacuum levels and hold times for testing tank <br /> secondary containment areas. Consult tank manu- r "s <br /> facturer and authority having jurisdiction (AHJ) A. <br /> I <br /> guidelines before performing these tests. as their <br /> requirements may differ. <br /> Determine if there is liquid present in the intersti- <br /> tial space. If liquid is found,determine if the fluid * ' <br /> is water or product, and remove it to the extent <br /> practicable. FIGURE 4.3. The vacuum gauge and control valve used <br /> e <br /> The hydrostatic pressure from a high water table for tank interstitial testing. <br /> imposes inward pressure on the outer wall of a <br /> UST. Applying a vacuum to the interstitial space <br /> of the tank creates additional pressure on the outer <br /> wall. These combined forces can damage the <br /> secondary tank wall when there is a large defined <br /> space between the primary and secondary tanks. , <br /> Consequently, to prevent damage to the tank, it is ti <br /> important to observe the water table and associated <br /> recommended vacuum levels when testing. a <br /> t - <br /> Vent the primary tank to atmosphere during the '- <br /> test. ` <br /> In some installations, the tank interstitial space <br /> may be vented to minimize the buildup of conden- <br /> sation. in these cases, seat off any vent lines to the <br /> tank interstitial space prior to testing. <br /> Determine the volume of the tank. This informa- <br /> tion is available from facility records or the auto- <br /> matic tank gauge(ATG)readout. <br /> 4.2.5 Steel Tanks. Determine if the interstitial <br /> space is a"tight-wrap"design or a"110%contain- <br /> ment" design. Tanks with a 110% containment <br /> design should use the latest version of Steel Tank <br /> Institute's (STI) RO12.Recommended Pracrice for <br /> latersrifial Trghfness Testing of Existing Under- FIGURE 4-4. The plumber's plug provides a leak-tight <br /> ground DoubleVttYLe!Tanks for t­11esting. connection to draw a vacuum on the tank interstitial <br /> space. <br /> JUN 10 2029 pei.org 0 <br /> ENVIRONMIEN TIAL HEALTH <br /> DEPARTMENT <br />