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DETAILS OF EXTRUSION WELDING SYSTEM I. Introduction The Hot Wedge Welding System is the primary seaming system for FML installation and the Extrusion Welding System is utilized for repairs and detail work. The extrusion Welding System produces a seam quality equal to the Hot Wedge Weld and has the advantage that all welds aze applied on top of the FML which allows its use at "T" intersections and in itregulaz seam azeas such as pipe boots. When tested in peel, the numerical values for weld strength of an extrusion weld will be slightly lower than for hot wedge weld (see Pazagraph 3.3.8.6, page 16 of this manual). The lower value is the result of the weld bead on top of the liner changing the geometry of the test and not an indication of inferior weld quality. II. FivIL Preparation A. FivIL prepazation is the same as described for the hot wedge weld on Page 2 of Appendix B. III. Equipment Preparation A. ,~, working and properly functioning small electric generator must be available within close proximity of the seaming region and with adequate extension cords to complete the entire seam. The generator must be rubber tired, or place on a smooth plate such that it is completely stable so that no damage can occur to the FML. Fuel (gasoline or diesel) for the generator must be stored off the FML. B. The extrusion welder is a completely self contained system which requires no adjustments after it has been initially set up for a particulaz FN1L thickness. C. An initial inspection of the extrusion welder should be made before the first heat up to corm that the electrical cords, insulation and covers aze in good condition. D. The welding machine should be connected to a proper power supply and heated to the correct welding temperature for the FML to be seamed. E. After the unit has reached correct operating temperature, clean, dry welding rod should be inserted and the unit operated for several minutes to Si