COMPLIANCE INFO_1990-2001 - Laserfiche WebLink

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TRENCHING, BACKFILL When the pavement is an asphalt mix at least 2 inches thick, a minimum of 8 AND BEDDING (Cont'd) inches of sand, pea gravel or crushed stone is recommended between the top of the pipe and the bottom of the pavement. A trench width of three times the pipe diameter is recommended for a single line. For multiple lines in the same ditch, separate the pipes by at least 4 inches and 6 inches from the trench wall. Although fiberglass pipe has high strength properties, it must be protected against impact damage which is most likely to result either from improper handling or during backfilling. Sand, pea gravel or crushed stone are recommended as padding to protect the pipe from rock damage during backfill and against abrasion during operation. Four to six inches of sand, pea gravel or crushed stone should surround the pipe. When the pipe is laid near or through concrete, it must be wrapped with rubber or foam padding to avoid direct contact, and the subgrade should be well compacted to prevent differential settling. When it is required that the vent piping have Secondary Containment, the steel riser pipes must be supported by something other than the vent or containment piping, as their weight may prevent good bonds and therefore leaks are likely. DRY FITTING Island forms, boxes, and shear valves should be in place before proceeding with PRIMARY PIPING piping. It is necessary to completely dry fit the product lines, before attempting to install the Secondary Containment system. Allow sufficient clearance when dry fitting to accommodate dimensions of Secondary Containinent fittings as shown in fittings section. DO NOT BOND PRIMARY SYSTEM TOGETHER BEFORE THE SECONDARY CONTAINMENT SYSTEM HAS BEEN DRY FITTED. DRY FITTING Only after the primary piping has been completely dry fitted can assembly of the SEONDARY Secondary Containment system proceed. CONTAINMENT SYSTEM The following are special tools needed to install Secondary Containment piping: One or more 3/8 inch electric drill. One 1-1/4 inch hole saw if installing saddles. Several 1-1/2 inch diameter by 1 inch wide coarse grit flapper sander wheels. One or more heavy duty heat guns, hot air blowers or Heat Blankets if installing system in cool or cold weather. Some Secondary Containment piping may be received with tapered ends. These tapers must be cut off before installation. The sealing of fittings to Secondary Containment piping requires sanded, square cut pipe.