Laserfiche WebLink
��PEIIRP1200.12_ <br /> 4.2.4 Preparation. The procedures in this sec- 4.2.7 Test Equipment. Test equipment shall <br /> tion are general in nature and reflect the suggested include: <br /> vacuum levels and hold times for testing tank . a vacuum-generating device that can be used in <br /> secondary containment areas. Consult tank manu- a Class 1. Division 1 area capable of pulling 15 -� <br /> facturer and authority having jurisdiction (AHJ) inches of mercury (Hg) vacuum: <br /> guidelines before perfomning these tests as their <br /> requirements may differ. • an automatic vacuum shutoff valve or vacuum <br /> regulator(Thr shutoff valve can be set to close at <br /> Determine if there is liquid present in the intersti- a predetermined safe level, preventing the pos- <br /> tial space. If liquid is found. determine if the fluid <br /> is water or product. and renim • it to the eitem <br /> practicable. <br /> The hydrostatic pressure from a high water table (- <br /> imposes inward pressure on the outer wall of a `! 4 <br /> [IST. Applying a vacuum 10 the interstitial space <br /> of the tank creates additional pressure on the outer » <br /> wall. These combined forces can damage the r} <br /> secondan, tank wall when there is a large defined <br /> space between the primary and secondary tanks. � l <br /> Consequently. to prevent damage to the tank. it is :. <br /> important to observe the water table and associated <br /> recommended vacuum levels when testing. t' <br /> Vent the primary tank to atmosphere during the. FIGURE 4-3. The vacuum gauge and control valve used <br /> test for tank interstitial testing. <br /> In some installations, the tank interstitial space <br /> tray be %rated to minimise the buildup of conden- <br /> sation. in these cases. seal off any vent lines to the <br /> tank interstitial space pour to testing. <br /> Detetnune 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.S Steel Tanks. Determine if the interstitial 1` <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 (STO Recommended Practice R012. <br /> Recommended Practice for htteruitial Tighrne <br /> Testing of F_risting Underground Douhle Will Sit i <br /> Tank% for testing. <br /> For tight wrap tank.~, use the test method in this <br /> section_ <br /> 4.2.6 Fiberglass Tanks. Determine if the inter- <br /> stitial space is a "tight N%rap" design or a "110"r <br /> containment"design. Either type of fiberglass tank <br /> may use this test. or the latest version of Fiher- <br /> glass Tank & Pine Instinite's, Field Test Pmrtprol <br /> for Testing the Annular Snare of Installed Under- FIGURE 4-4. The plumber's plug;provides a leak-tight --� <br /> ground Fiher;t;lass Double and Triple-►roll Tanks connection to draw a vacuum on the tank interstitial <br /> frith Dn,Annular Spare. Fr&PIX 101107. space. <br /> 0 pei.org <br />