COMPLIANCE INFO_1998-2006 - Laserfiche WebLink

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• 1.6.1 Piping Layout Advance planning of the piping lay- out inessential. It will make servicing the system easier and can reduce the quantities of material required. 1. Using the shortest practical route, run the pipe in a single trench from the tanks to the vent risers. 2. Pipe should run parallel to the tanks and dispensers. 3. Avoid piping across the tanks 1.6.2 Trenching and backfilling Proper construction of trenches is important. They should be wide and ------------ a deep enough to accommodate the piping and backfill material. See Table 1.6.1 for recommended mini- mum burial depths. 1. Typically, all piping should slope at least 1/8 inch (3mm) per foot toward the tank. Support pipe properly to prevent traps or su mps. FIBERGLASS 2. The piping should be separated by a distance of at least four to six inches (100-150mm); the pipe and trench wall should be separated by at least six inches (150mm). See Figure 1.6.3. For double-wall secondary containment piping in- stallations, refer to Part Two, Sec- TABLEFigure 1.6.1 1.6.1 RECOMMENDED MINIMUM BURIAL DEPTHS BASED ON SOIL MODULUS OF 1,000 PSI OR HIGHER (Refer to ASTM D3839 or AWWA C950 for Method/Theory) 10 Min. Amount of Sand Pipe Size Surface Condition Minimum or Pea Gravel above Burial Depth the Top of the Pipe (in.) (mm), (in.) (in.) (rnm) 2 50 Unpaved 17 432 12 305 Paved, min. 4" (100mm) asphalt 12 305 ' 8 203 Paved, min. 4" (100mm) concrete 9 229 5 127 3 75 Unpaved 20 508 14 356 Paved, min. 4" (100mm) asphalt 13 330 9 229 Paved, min. 4" (100mm) concrete 11 279 7 178 4 100 Unpaved 20 508 14 356 Paved, min. 4" (l 00mm) asphalt 14 356 10 254 Paved, min. 4" (100mm) concrete 11 279 7 178 10