AWWA C105-A21.5:2018 pdf download.Polyethylene Encasement for Ductile-Iron Pipe Systems
After assembling the pipe joint, make the overlap of the polyethylene tube. Pull the bunched polyethylene from the preceding length of pipe, slip it over the end of the new length of pipe, and secure it in place. Slip the end of the polyethylene from the new pipe section over the end of the first wrap until it overlaps the joint at the end of the preceding length of pipe. Secure the overlap in place. Take up the slack width at the top of the pipe as shown in Figure 2 to make a snug but not tight fit along the barrel of the pipe, securing the fold at quarter points. This step is extremely important to prevent sagging of the film at the bottom of the pipe.
Cuts, tears, punctures, or other damage to the polyethylene shall be repaired as described in Sec. 4.4.6. Proceed with the installation of the next section of pipe in the same manner.
4.4.3.2 Modified Method A (Refer to Figure 3). This is a modification of Method A, which uses one length of polyethylene tube for each length of pipe. In this modified method, one end of the tube is secured with circumferential tape to the spigot prior to making the joint. The 12-in. (300-mm) overlap is achieved when bringing the remaining film over the joint from the previous length of pipe.
Cut a section of polyethylene tube approximately 1 ft. (300 mm) longer than the pipe section. Remove all lumps of clay, mud, cinders, or other material that might have accumulated on the pipe surface during storage. Slip the polyethylene tube around the pipe, starting at the spigot end. Bunch the tube accordion- fashion on the end of the pipe. Pull back the overhanging end of the tube and circumferentially tape it to the barrel of the pipe behind the insertion line. After assembly of the joint, the tape should be as close to the face of the bell as possible but not so close to the spigot end that it interferes with the gasket.AWWA C105-A21.5 pdf download.