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® Verify there is no free moisture in the weld area. <br /> 5.2.9 Non Destructive Seam Testing <br /> The purpose of nondestructive geomembrane seam testing is to detect discontinuities or holes in <br /> the seams. Nondestructive geomembrane tests include vacuum and air pressure testing. <br /> Nondestructive testing must be performed over the entire length of the seam. <br /> It is the installer's responsibility to perform all nondestructive testing as part of his QC program, <br /> record the results and report the results to the CQA monitor. The CQA monitor's responsibility is <br /> to observe and independently document that the installer's QC testing is in compliance with the <br /> technical specifications and to independently document seam defects and panel defects that the <br /> installer detects. <br /> Nondestructive testing procedures are described below: <br /> Vacuum Testing <br /> For welds tested by vacuum method the weld is placed under suction utilizing a vacuum box <br /> constructed with rigid sides, a transparent top for viewing the seams, a neoprene rubber gasket <br /> attached to the bottom of the rigid sides, a vacuum gauge on the inside, and a valve assembly <br /> attached to a vacuum hose connection. The box is placed over a seam section that has been <br /> thoroughly saturated with a soapy water solution (1 ounce soap to 1 gallon water). The rubber <br /> gasket on the bottom of the box must fit snugly against the soaped seam section of the panel, to <br /> ensure a leak-tight seal. A vacuum pump is energized and the vacuum box pressure reduced to <br /> approximately 5-psi gauge. Any pinholes or non-bonded areas are detected by the appearance of <br /> soap bubbles in the vicinity of the defect. Dwell time is a minimum of 10 seconds. <br /> Air Channel Pressure Testing <br /> Air pressure testing is used to test double seams that have an enclosed air space between them. <br /> Both ends of the air channel must be sealed. A pressure feed device, usually a needle equipped <br /> with a pressure gauge, is inserted into one end of the channel. Air is then pumped into the <br /> ' channel to a minimum specified pressure. A five-minute relaxing period is allowed for the <br /> pressure to stabilize. The air chamber must sustain the pressure as specified in the technical <br /> specifications. Following a passed pressure test, the opposite end of the tested seam must be <br /> punctured to release the air. The pressure gauge must return to zero, if not, a blockage is likely <br /> in the seam channel. When a blockage is detected it must be located and the seam re-tested on <br /> both sides of the blockage. The penetration holes must be repaired after testing. <br /> During nondestructive testing, the CQA monitor must: <br /> ' ® Review technical specifications regarding test procedures and verify all testing is <br /> completed in accordance with the technical specifications. <br /> ® Verify equipment operators are fully trained and qualified to perform their work <br /> ® Verify test equipment meets project technical specifications. <br /> CH CQA Plan 041712 Rev2a.doc 5.8 Construction Quality Assurance Plan <br />