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B. Seam Layout. <br />1. Orient seams parallel to line of a maximum slope, i.e., orient down not across <br />slope. <br />2. Minimize number of field seams in corners, odd -shaped geometric locations <br />and outside corners. <br />3. Keep horizontal seams (seams running approximately parallel to slope <br />contours) at least 5 feet away from toe or crest of slope, unless approved by <br />DESIGN ENGINEER. No horizontal seams shall be allowed on the slope. <br />4. Use seam numbering system compatible with panel number system. <br />5. Shingle panels on all slopes and grades as directed by QA/QC <br />CONSULTANT. <br />6. Longitudinal seams shall not be allowed in the LCRS trenches. <br />C. Seam Welding Personnel. <br />I . Provide at least one welder (master welder) who has experience welding over <br />5 million square feet of geomembrane using the same type of welding <br />apparatus in use at site. <br />2. Qualify personnel performing welding operations by experience and by <br />successfully passing field welding tests performed on site. <br />3. Master welder will provide direct supervision over other welders. <br />D. Seam Welding Equipment. <br />1. Extrusion. welder: equipped with gauges showing temperatures in extruder <br />apparatus and at nozzle. Temperature at nozzle may be measured by external <br />temperature gauges. <br />® 2. Hot wedge welder: Automated variable speed vehicular mounted devices <br />equipped with devices adjusting and giving temperatures at wedge. Pressure <br />controlled by spring, pneumatic, or other system that allows for variation in <br />sheet thickness. Rigid frame fixed position equipment is not acceptable. <br />3. Maintain adequate quality of welding apparatus in order to avoid delaying the <br />project. <br />4. Use power source capable of providing constant voltage under combined line <br />load. <br />E. General welding procedures: <br />1. <br />Do not commence welding until trial weld test sample, made with the <br />equipment to be used passes trial weld test. <br />2. <br />Clean geomembrane surface of grease, moisture, dust, dirt, debris, and other <br />foreign material. <br />3. <br />Overlap panels a minimum 3 inches for extrusion and 4 inches for hot wedge <br />welding. <br />4. <br />Do not use solvents or adhesives unless product is approved in writing by the <br />DESIGN ENGINEER. <br />5. <br />Provide adequate material on weld to allow peel testing of both sides of <br />double wedge weld. <br />6. <br />Extend welding to the outside edge of all panels. <br />7. <br />If required, provide a firm substrata by using a flat board, a conveyor belt, or <br />similar hard surface directly under the weld overlap to achieve firm support. <br />Forward Landfill WMU FU -14 HIGH DENSITY POLYETHYLENE <br />i02778 14 (HDPE) GEOMEMBRANE <br />