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IMPORTANT: The instructions below for the 71 SO <br />Overfill Prevention Value are written for the initial <br />stage shutoffat 95%, but can be adjusted to shutoff <br />at any desired tank capacity. Please contact the Au- <br />thority Having Jurisdiction (AHA and review local, <br />state, and national codes to determine the regulato- <br />ry requirements governing shut-off capacity in your <br />region, as well as take into account other considera- <br />tions such as extreme tank tilt. In all cases, the up- <br />per tube must protrude into the tank at least 6112" <br />to ensure that the valve can shut off flow into the <br />tank completely before the top of the tank is wetted <br />as per EPA requirements. <br />HOW TO LOCATE THE POSITION OF THE 71 SO AT <br />95% TANK CAPACITY <br />(Shut-offpoints can be adjusted to arty capacity to <br />comply with AHJ Requirements) <br />The length of the upper tube and the placement of the <br />71 SO valve body determine the shut-off point. Follow- <br />ing the standard instructions for the OPW 7150 will pro- <br />vide for initial shutoff at 95%. In all cases, the upper <br />tube length must be a minimum of 6-112" plus the <br />length of the riser pipe. All length measurements are in <br />inches. <br />INSTRUCTIONS <br />1) Find tank capacity (in gallons) from tank calibration <br />chart provided by tank manufacturer. <br />2) Calculate 95% of capacity <br />3) Locate the 95% volume number on the tank calibra- <br />tion chart. <br />4) Find the dipstick number (X) which corresponds to <br />the 95% tank volume. And, find the dipstick num- <br />ber (Y) which corresponds to the 100% volume. <br />5) Subtract the dipstick number (X) from the tank di- <br />ameter (Y) to find the upper tube reference number <br />(Z). <br />M - (x) = (Z) <br />6) Subtract 2" from W to find the upper tube depth <br />(C). <br />(Z) - 2" = C <br />7) Is C less than 6-112"? <br />NO Lipper tube length is C plus the distance from <br />the top of the Face Seal Adaptor installed on <br />the riser pipe to the inside, top lip of the storage <br />tank (A). <br />Upper Tube Length = C + (A) <br />For testable models only, ending in "T": <br />Upper Tube Length = C + (A) --1-112" <br />YES Lipper tube length is 6-112" plus the riser pipe <br />measurement (A). <br />Lipper Tube Length = 6-112" + (A) <br />For testable models only, ending in "'T". <br />Upper Tube Length = 6-1)2" + (A) -1-112" <br />NOTE: You must find the actual tank capacity num- <br />ber that correlates to the 6-112" + (A) depth for the <br />station records. This number may also be used for <br />the purposes of calibrating an electronic tank level <br />system. <br />Tape measure <br />Riser Pipe <br />with Face (A) <br />Seal Adaptor To Tank <br />Topi <br />l.d.} (B) <br />To Tank <br />By vm <br />Figuiv 7 <br />EXAMPLE <br />1) For an Owens-Corning Model Cr3 Fiberglass" Tank <br />Calibration Chart: <br />Tank Capacity- 10,000 gal., nominal 9,403 gal. <br />NOTE: Use actual capacity only <br />2) 95% of actual tank capacity = 0.95 x 9403 gal. _ <br />8933 gal, <br />3) The closest number which is less than 8933 gal. Is <br />8910 gal. Choosing the closest number less than <br />95'0 of actual capacity ensures that the initial <br />shutoff will occur when the tank is no more than <br />95%full_ <br />4) The calibration chart reading of 6910 gal. corre- <br />sponds to a dipstick measurement of 82". <br />4 <br />