Laserfiche WebLink
I <br /> ®e® 4 <br /> doubi <br /> 6�4`� all ft •®®b1' t•'® L .� a-[d'«i-.1 a..._...........a_a_... .....r.« 2c.._._.,..`-s.,._...T.C.iw-`w..✓...�r_a....,. <br /> 'Xerxes DWT-II double wall tanks with the TRU-CHEK®system <br /> option are factory-filled with a brine solution in the interstice Diagram A <br /> between the two tank walls.The brine also partially fills a Reservoir <br /> reservoir affixed to the top of the tank.This creates a hydrosta- Level Down <br /> tic pressure that enables owners/users to monitor both the <br /> primary tank and the secondary tank wails. <br /> The TRU-CHEKe system provides a simple-and precise method <br /> to perform a tank-tightness test. It was developed in conjunc- <br /> tion <br /> onjunction with Dr. Robert Plunkett, Sc.D., consulting engineer(pro- <br /> fessor emeritus), University of Minnesota.TRU-CHEKe has <br /> received third-parry verification from Underwriters <br /> Laboratories. <br /> TRU-CHEKe testing meets the EPA criteria for tank-tightness <br /> testing,which states that a test must be able to detect a leak <br /> rate of 0.1 gallon per hour from any portion of the tank that <br /> routinely contains product.The test has a 95%probability of <br /> detection (PD) and a 5%probability of false alarm (PFA). In <br /> other words, out of 100 chances, the test detects leaks 95% <br /> of the time. <br /> The test must also account for the effects of thermal expan- <br /> sion or contraction of the product,vapor pockets, tank defor- <br /> mation, evaporation, condensation and the location of the Diagram B <br /> water table. <br /> TRU-CHEKe is capable of detecting a loss rate as small as the Reservoir <br /> NFPA 329 criteria of 0.05 gallons per hour. Level Down <br /> In addition, on extended tests,TRU-CHEKe testing offers 99% <br /> PD and 1%PFA. <br /> rhe TRU-O test offers significant <br /> benefits to the owner/operator: <br /> LA wide range of tank sizes can be tested, including <br /> Xerxes DWT II tanks up to 20,000 gallons. <br /> 2.Product can be dispensed during the 95%/5%test. <br /> 3.No waiting time is required to start the test as long as a <br /> fill of new product does not vary more than 20°F from <br /> the existing product temperature. <br /> Now continuo-us monitoring works <br /> If both the inner and outer walls are Diagram C <br /> tight, the reservoir level will be stable. <br /> If there is a fracture in the inner wall ""'^"- ^^ <br /> --�-�- -�----�-�- —Reservoir, <br /> (Diagram A), the brine level in the reser I Levet up " <br /> voir will go down.The brine level will <br /> also go down if there is a leak in the .Water Level <br /> outer wall(Diagram B). ,. M Above Tank <br /> With a high-water table and"wet-hole" �~ ��.Fracture <br /> conditions (Diagram C), a leak in the Outer Walt <br /> outer wall will cause the brine level <br /> to go up if the height of the <br /> water table above the leak is <br /> 30%greater than the <br /> brine level above the.leak. <br /> See Xerxes TRU-CHEKe <br /> .,ochure for more <br /> ':•Mails. ^^ <br /> 16 <br />