COMPLIANCE INFO 1985-2006 - Laserfiche WebLink

Home Browse Search

r*UB .E WALL TANKS M¢y 1, 1996 ,MIMMEg"12M Underground Storage Tanks F IN liea� z� k� UL1746 Part III, Section 20.9 Interstitial Communication Test . (measures the ability of a double-wall tank to transmit liquid through annular space while it's buried and filled with fluid) UL Requirements For Test Procedures Mandated May 15, 1995 20.9.1 A representative tank is to be installed underground as intended.The primary tank is to be filled to capacity with water At a point farthest from the interstitial monitoring point,water,rated vacuum,or rated pressure is to be added to the interstitial space. 20.9.2 The communication of the water, vacuum, or pressure to the monitoring point is to be monitored and timed. There shall be measurable communication in less than 24 hours. Sample Product TCI submitted an 8'diameter,10,000 gallon,26'-8"long jacketed tank to evaluate compliance to the Interstitial Communica- tion Test requirements of UL1746,effective 5/15/95. Test Method The sample jacketed tank was placed on a bed of sand such that the bottom 1200 was covered.The primary tank was filled to capacity with water. A standpipe was attached to the primary fill fitting and an additional 111' of water was added to simulate the pressure that would exist at the bottom of a 12'diameter tank buried to a depth of 3'.Rated vacuum of 12"Hg was added to the interstitial fitting at one end of the tank The communication of the vacuum to the monitoring fitting at the opposite end of the tank was monitored and timed. After the vacuum fully communicated to the monitoring fitting, the vacuum was released and the communication was monitored and timed The test was repeated,except that water was added to the monitoring fitting instead of vacuum. Test Results Test Media Vacuum Communication Time Maximum UL Requirement Vacuum 0-12 in. Hg. 14 min- '535 min. 12.0 in. Hg. 1.5 min. 535 min. Water 4,5 min. 535 min_ TOTAL CONTAINMENT® Tsyzaa.s