COMPLIANCE INFO_2001-2005 - Laserfiche WebLink

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Trenching,bedding Recommended practices and backfilling Although fiberglass pipe has excellent strength,it must be protected against impact which may occur from improper handling or during backfilling. • Provide a trench width equal to the pipe diameter plus six inches on each side. Separate multiple lines by at least 4 inches.Refer to Fig.5-1. • Provide a minimum of 18 inches of select backfill between the top of the pipe and unpaved ground surfaces. • Provide a minimum of 4 inches of select backfill between the top of the pipe and reinforced concrete pavement(4 inches minimum thickness). • Provide a minimum of 8 inches of select backfill between the top of the pipe and asphalt pavement(2 inches minimum thickness). • Slope the trench bottom evenly from the dispensers back to sumps or tanks at a minimum'/a in/ft. • Maintain the trench bottom free of hard or sharp objects. • Grade the trench bottom with at least 6 inches of select backfill to provide firm, even support for the pipe.Compact the subgrade well to prevent differential settling. • Protect the pipe from impact during backfilling and abrasion during operation by surrounding it with four to six inches of select backfill such as washed sand,pea gravel('/4-inch maximum)or crushed stone('k-inch maximum). • Wrap pipe lying near concrete with rubber or foam padding to avoid direct contact with the concrete. No pavement —` Asphalt--N 2(in) Concrete 4(min) F _ 18(min) 8(min) 4(min) Fig.5-1.Use only select materials i o -C for bedding and backfilling iSelect backfill Dualoy 3000/1-fuel handling C 6(min) systems.Native materials are rarely suitable and ��YJ�1Y/1111 should not be used. Native soil 4(ftp 6(min) Aft Dry fittingContained Recommended practices primary piping Have island forms,boxes,and shear valves in place before dry fitting. • Lay out and dry fit primary and containment piping at the same time. • Allow sufficient clearance when dry fitting the primary to accommodate the containment fittings. Dimensions of containment l fittings may be found at the end of this document. Fig.6-1.During layout,bonding �� ^�' and inspection,support the r piping on 2x4 blocks to keep the ,F ' Do not bond primary system I joints clean and to keep bedding together before the out of the pipe.RemoveI secondary containment I supports before burial '�� system has been dry fit. L�----- -----� 5