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Forward Landfill WMU FU-23 <br />02778 13 HDPE GEOMEMBRANE <br />C. Seam Welding Personnel. 1. Provide at least one welder (master welder) who has experience welding over 5 million square feet of geomembrane using the same type of welding apparatus in use at site. 2. Qualify personnel performing welding operations by experience and by successfully passing field welding tests performed on site. 3. Master welder will provide direct supervision over other welders. <br />D. Seam Welding Equipment. 1. Extrusion welder: equipped with gauges showing temperatures in extruder apparatus and at nozzle. Temperature at nozzle may be measured by external temperature gauges. 2. Hot wedge welder: Automated variable speed vehicular mounted devices equipped with devices adjusting and giving temperatures at wedge. Pressure controlled by spring, pneumatic, or other system that allows for variation in sheet thickness. Rigid frame fixed position equipment is not acceptable. 3. Maintain adequate quality of welding apparatus in order to avoid delaying the project. 4. Use power source capable of providing constant voltage under combined line load. <br />E. General welding procedures: 1. Do not commence welding until trial weld test sample, made with the equipment to be used passes trial weld test. 2. Clean geomembrane surface of grease, moisture, dust, dirt, debris, and other foreign material. 3. Overlap panels a minimum 3 inches for extrusion and 4 inches for hot wedge welding. 4. Do not use solvents or adhesives unless product is approved in writing by the DESIGN ENGINEER. 5. Provide adequate material on weld to allow peel testing of both sides of double wedge weld. 6. Extend welding to the outside edge of all panels. 7. If required, provide a firm substratum by using a flat board, a conveyor belt, or similar hard surface directly under the weld overlap to achieve firm support. 8. Provide adequate illumination if welding operations are carried out at night, and night operations are approved by the OWNER. 9. Cut fish mouths or wrinkles along the ridge of the wrinkle in order to achieve a flap overlap. Extrusion weld the cut fish mouths or wrinkles where the overlap is more than 3 inches. When there is less than 3 inches overlap, patch with an oval or round patch extending a minimum of 6 inches beyond the cut in all directions. 10. Log every 2 hours: a. Temperature directly on the geomembrane surface being welded. b. Extrudate temperatures in barrel and at nozzle (extrusion welder). c. Operating temperature of hot wedge (hot wedge welder) and any pressure adjustments made. d. Preheat temperature. e. Speed of hot wedge welder in feet per minute.