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Using a Manifold From The Inner Tan, _ ressurize A4. Hole Size "ass"Tank Cavity To 5 psi Maximum. Stable Walls a,s, _ In stable soil conditions for 4' „ vauedreee --N i�`� : �\ through l O'diameter tanks (550-20,000 gallons),the hole 1k iI It must be large enough to allow a I I I t, I minimum of 18"(24"preferred) II II I between adjacent tanks and 18" I I I r r i (24"preferred)between the tank sides and ends and the banks of the hole. nariaa system Is+rovkd�+a+ l r I� Twelve-foot diameter tanks Step#3 _ L4'-10' Minimum 18" (25,000-48,000 gallon models), 12' Minimum 24• require 24"betweentanksand Ste #3 hole sides,and require 24" P between adjacent tanks. Pressurize the cavity between the inner and outer tank to 5 psi maximum by opening the manifold valve thereby transferring pressure from the - Unstable walls(all size tanks) innertank. _ In muck,bog,peat,swamp,or DO NOT CONNECT THE AIR SUPPLY DIRECTLY TO THE landfill type areas where the soil is MONITORING FI TTI NG OR ALLOW THE MANIFOLD VALVE TO BE r , soft or in areas with expansive clay OPEN DU RI NG STEP#1.Typical air compressors can over - -T All Diameters soils,a larger hole is required to pressurize(over 5 psi)the tank cavity between the inner tank and - ' t I support tanks.In these types of outer wall in less than 2seconds. 4, ,l - conditions,the holes must be large n--d I '�r' enough to allow a minimum of V2 Step ll I t the tank diameter from ends and Monitor the pressure on both the inner tank and cavity between the inner f '' sides of tanks to hole walls. and outer ank for at least 30 minutes.Soap the outer tank and check for t , leaks as indicated by bubbles.An outer wall leak detected before backfill- v . Unstable soils are defined as those ing is simple to repair.Do not backfill a tank with a known or m- soils having less than 7501bs./sq. suspected leak in the outer wall. %ola.min. ft.cohesion as calculated from an P _ e«ons,aoie watts unconfined compression test;or Inner Wall Test soils with an ultimate bearing 1 capacity of less than 3500lbs./sq.ft.Unstable soils or areas with expan- i Step#5: sive clay may require a reinforced concrete slab under tank for support. Close the manifold valve to the cavity between the inner and outer wall. For unstable soils with less than 250 lbs./sq.ft.cohesion or with an Release the pressure and vent the primary tank(byopening the air ultimate bearing capacity of less than SOO lbs./sq.ft.,afilter fabric hole i supply between theibutmaintainthe5psi maximum pressure on the cavity liner is recommended to prevent backfill migration. Refer to Section A6. between the inner and outer walls. i Step#6: Its Monitor the air gauge on the tank monitoring fitting for another 30 minutes,but not more than 60 minutes.Longer tests conducted during changing temperatures or changing cloud cover may distort test results 211l t 1 psi. In the unlikely event a tank leak is discovered with any of the above tests,call the O/C Tanks Field Service Manager to schedule a tank repair.Do not attempt to repair the tank.Telephone: (419)24&6196. DO NOT EXCEED 5 PSI DURING AIR TEST. t After successfully completing theairtest,disconnect and remove the air manifold fittings,hose,and valve. Before backfilling to grade,O/C recommends a 5 psi air/soap test on all finished piping connections and unused tank fittings. _7, z