INSTALL_2003 - Laserfiche WebLink

Home Browse Search

TRU-CHIEKIMM"I rin' * System double wall'p_r`d;tettiofi at it s* best'. Xerxes DWT-11 double wall tanks with the TRU-CHEKS system option are factory-filled with a brine solution in the interstice Diagram A between the two tank walls. The brine also partially fills a Reservoir reservoir affixed to the top of the tank. This creates a hydrosta- Level Down tic pressure that enables owners/users to monitor both the primary tank and the secondary tank walls. The TRU-CHEK@ system provides a simple and precise'rnethod to perform a tank-tightness test. It was developed in conjunc- tion with Dr. Robert Plunkett, Sc.D., consulting engineer (pro- fessor emeritus), University of Minnesota. TRU-CHEK@ has received third-party verification from Underwriters Laboratories. d TRU-CHEKS testing meets the EPA criteria for tank-tightness testing, which states that a test must be able to detect a leak rate of 0.1 gallon per hour from any portion of the tank that routinely contains product. The test has a 95%probability of detection (PD) and a 5%probability of false alarm (PFA). In other words, out of 100 chances, the test detects leaks 95% of the time. The test must also account for the effects of thermal expan- sion or contraction of the product, vapor pockets, tank defor- mation, evaporation, condensation and the location of the Diagram B water table. TRU-CHEK@ is capable of detecting a loss rate as small as the Reservoir NFPA 329 criteria of 0.05 gallons per hour. Level Down In addition, on extended tests, TRU-CHEK@ testing offers 99% PD and I% PFA. The TRU-CHEV test offers significant benefits to the owner/operator: I A wide range of tank sizes can be tested, including Xerxes DV,/T-11 tanks up to 20,000 gallons. 2.Product can be dispensed during the 95%/5%test. 3.No waiting time is required to start the test as long as a fill of new product does not vary more than 20OF from the existing product temperature. How continuous monitoring works If both the inner and outer walls are Diagram C right, the reservoir level will be stable. If there is a fracture in the inner wall Reservoir (Diagram A), the brine level in the reser- -/Level Up voir will go down. The brine level will also go down if there is a leak in the Water Level outer wall (Diagram 6). Above Tank With a high-water table and "wet-hole" Fracture conditions (Diagram C), a leak in the Outer Wall outer wall will cause the brine level b to go up if the height of the water table above the leak is 30%greater than the brine level above the leak. See Xerxes TRU-CHEKO brochure for more details. 16