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around the pipe. The trench was then backfilled and compacted and the trench for the <br />next section was excavated. <br />Approximately half the 24-inch HDPE pipe was fused at the upper yard, near the <br />new Discharge Vault. The other half of the pipe was fused at the lower yard, near the <br />Storke Portal. This reduced the distance the pipe had to be dragged into position. <br />To make the final connection to the existing pipeline in the PT, it was necessary <br />to install a temporary "bypass" line, fabricated from 16-inch HDPE pipe. It was then <br />possible to cut open the existing discharge line, and connect the bypass section. The <br />bypass line allowed water to continue to be pumped from #5 Shaft while the rest of the <br />new 24-inch HDPE pipeline was installed. The bypass line was installed by drilling a <br />hole through the concrete roof of the PT, and connecting the bypass line to the existing <br />16-inch HDPE pipeline in the PT. Once the 24-inch HDPE pipeline was completed, the <br />bypass line was removed. <br />Extreme care was used in fusing, or welding, fhe HDPE pipe sections. The pipe <br />ends were faced, heated to the proper temperature, and then forced together with the <br />recommended pressure and for the recommended time while cooling occurred. These <br />settings were as per the manufacturer's recommendations. To insure that the joints <br />were made correctly, the project's QA/QC program required that the personnel fusing <br />the pipe joints be factory trained and qualified. In addition, every joint was "data logged" <br />to insure that the proper procedure was used. This process produced a strip chart for <br />each weld, which showed the fusion pressure applied, the time the joint was heated for, <br />and the time the fusion pressure was applied for. The heater temperature was also <br />recorded. This information was also recorded electronically. The fusion time and <br />pressure were calculated for each pipe diameter and SDR change, and was based on <br />the recommendations of the pipe manufacturer. To verify that the fusion equipment was <br />set up correctly, at the beginning of every day, and every time the pipe diameter or SDR <br />changed, a test fusion joint was made and inspected. This occurred before an actual <br />production fusion joint was made. The test fusion joint then had a strip of material cut <br />out, and this test strip was then visually inspected for defects, and bent to see if any <br />L <br />