This standard describes materials and installation procedures for polyethylene encasement to be applied to underground installations of ductile-iron pipe. This standard also may be used for polyethylene encasement of fittings, valves, and other appurtenances to ductile-iron pipe systems. Major revisions made to the standard in this edition include the following: the definition of high-density cross-laminated polyethylene film was revised to more clearly define the lamination process (Section 3); new Sec. 4.1.1 was added to emphasize the use and requirements of virgin polyethylene for film; a minimum thickness requirement for the required tensile strength and a minimum tensile strength per width of film was added for linear low-density polyethylene film and high-density cross-laminated polyethylene film (Sec. 4.1.2.2 and Sec. 4.1.3.2); the minimum elongation was reduced from 800 percent to 700 percent for linear low-density polyethylene film (Sec. 4.1.2.2); the section on color of polyethylene film was reworded for clarification and the maximum particle diameter for carbon black was increased based on the industry standard (Sec. 4.1.4); the section on marking requirements was revised (Sec. 4.3.1); a new section on requirements for polyethylene installers was added (Sec. 4.4.2); Sec. 5.1, Inspection and Affidavit of Compliance, was revised to provide firmer requirements to achieve verification; the first sentence of appendix Sec. A.1.4, Sulfides, was no longer accurate and was deleted; and, the phrase "salt/brackish water tidal area" was added under Sec. A.3, Uniquely Severe Environments, to help better define this environment (appendix A.3).