Polyethylene Water/Sewer - JM Eagle

or together with internal pressure to exceed material strength and causefailure. Excessive installed bending in plastic piping systems, particularly atjoints, can exceed stress limits and result in failure. Pipe where joined to fittingsshould be laid true to line and grade and backfilled carefully to preventdifferential settlement, and thus excessive bending. See “Permanent MinimumBending Radius Limits.”Excessive stresses and failure of plastic pipe can also result from impact,indentations or deflection. Avoid excessive compaction forces and particularlyavoid installation of the pipe against a source of point loading. The bedfor the pipe and fill materials around the pipe must be free of rocks, blockingmaterials or other sources of point loading or deflection. Heavy machinecompaction as by roller or hydrohammer should be used only for consolidationof final backfill with a minimum of 18 inches of previously layered andcompacted backfill.ASTM D2774, “Standard Recommended Practice for Underground Installationof Thermoplastic Pressure Piping,” provides additional information fordirect burial of JM Eagle Municipal & Industrial Water or Sewer Pipe.2.1.6 Plastic Pipe Damage & RepairIndustry surveys indicate the primary causes for repair of plastic piping arefrom third-party damage and poor workmanship in the initial installation. Repaircan be minimized by using careful mapping and location methods andby proper training and inspection procedures. Repairing PE pipe is similarto repairing ductile iron and PVC water pipe. Mechanical couplings or fusionmethods can be used for damage, such as puncture, rupture, or saddle repair.The first step in making a repair is determining the problem.For smaller sizes, an electrofusion system is useful in making repairs to polyethylenepipe.HDPE WATER/SEWER PIPING SYSTEM TECHNICAL & INSTALLATION GUIDE9