INSTALLATION QUALITY-ASSURANCE GUIDE FOR SOLMAX-GSE S CONDUCTIVE LINER These instructions present some general guidelines for installing and surveying Solmax-GSE s smooth edged conductive backed geomembranes for leaks. How to identify the conductive side: It is the outside surface of the roll. It is the opposite side of the printing line. Use a multi-meter to verify the continuity. Put the 2 wires on the same face. If there is continuity, this side is conductive. Use the spark tester: put the grounding pad and the electrode on the same face, away from the edges. If the alarm goes on, the conductive face is on top. General attributes of Solmax-GSE s conductive backed geomembranes 1. A co-extruded conductive surface: A layer of electrically conductive skin is coextruded with the geomembrane during the manufacturing process. Hence, one surface of the geomembrane is always electrically conductive, making it possible to use the geomembrane for leak detection and liner integrity surveys without the need for an external conductive underlay or subgrade beneath the geomembrane 2. Nonconductive smooth edges: Solmax-GSE s conductive backed geomembranes now have smooth edges that are nonconductive. The nonconductive smooth edges will reduce the hassles with installing conductive backed geomembranes, improve the overall efficiency of the welding process and improve leak location surveys with conductive backed geomembranes by eliminating the issue of false positives along the welded seams. INSTALLATION 1. Install the geomembrane with the conductive face down. Extra care must be taken when unrolling to ensure that conductive surface is facing down. On a patch, or a piece of geomembrane left on site, label each side visibly marking the conductive and non conductive sides. At the corners, do not flip (turn up side down). 1
2. Seams should be performed as per standard industry practices: No specific welding machine is needed. Special welding machines have been specified with some conductive geomembranes to scrape off conductive material from the seams during welding for good quality welds and to break conductivity across the welded seams. Solmax-GSE s conductive geomembranes now come with non conductive smooth edges, as such they can be welded without the need for a special welding machine to scrape off conductive material. Double channel hot wedge and extrusion fillet seams can be performed. Calibration of the welding machine should be done with the conductive layer facing down, using standard calibration procedures. Seam testing for leaks should be done in accordance with industry practices, such as ASTM D4437 not using the spark test. 3. It is possible to perform leak location surveys such as the water puddle (ASTM D7002) and dipole survey (ASTM D7007) on Solmax-GSE s conductive backed geomembranes. Tests have been realised with a third party consultant. Should you require more details, please feel free to contact Solmax-GSE. GETTING STARTED WITH THE HOLIDAY DETECTOR EQUIPMENT: Tinker & Rasor (contact your sales representative for more information.) Grounding pad Holiday detector Narrow rubber electrode Wide rubber electrode Wide brush electrode Accessories might change according to your application. 2 Rev. 11.17
There is a high risk of electrical shock. Make sure to use the spark tester properly. These instructions do not address all the safety concerns with the use of the holiday detector. Please read the operating manual carefully. Wear safety shoes/boots. Assemble the equipment as per manufacturer instructions. Make sure no connection is loose. Make sure the device is in good working condition. Do not use a broken device. Only one person at the time should operate the holiday detector. Do not use if there is water on the geomembrane. When the holiday detector is ON: Do not walk on the grounding pad. Do not touch the electrode. CALIBRATION AND ADJUSTMENT OF THE HOLIDAY DETECTOR STEP 1. Cut a piece of geomembrane of at least 3 m x roll width, and lay it flat on the ground with the conductive layer facing down. STEP 2. Make a pin hole with a diameter of not less than 1 mm in the geomembrane, at least one meter away from any edge. STEP 3. Lay the grounding pad on the geomembrane piece (intimate contact is important). STEP 4. Mount the wide electrode. STEP 5. Turn on the spark tester and put the spark tester on the high voltage scale. STEP 6. Adjust the voltage to 35 kv with the screwdriver provided by Tinker&Rasor. ON/OFF adjustment button Hight voltage scale Voltage adjustment 3
STEP 7. Adjust the sensitivity to detect the hole and to avoid false alarms. Always walk at normal speed when doing the calibration Once in a while, it is normal to have a false alarm a. Adjust the sensitivity in order to have a lot of false alarms b. Reduce the sensitivity and walk c. Note the number of false alarms d. Repeat steps b. and c. until there are almost no false alarms e. Once adjusted, move the electrode swiftly or run. It should provoke a false alarm. If it doesn t, it means the sensitivity is too low. Go back to step a. STEP 8. Walk on the pin hole. The alarm should be triggered and the spark should be visible. NOTE: Each time the spark tester is started, make sure to verify the voltage (35 kv) and adjust if necessary. When the spark tester is off for more than 5 minutes, it goes back automatically to low voltage scale. Listening to the electricity noise (not alarm) is another indication of the voltage. The lower the voltage, the lower the noise. If the voltage is too low even after adjustment: Make sure the equipment is fully charged. Verify that the charger is giving the right voltage. Verify the voltage of the battery. If it is lower than the manufacturer specification, it should be replaced immediately. NOTE: Electromagnetic field may affect the hole detection survey. The voltage and/or the sensitivity of the holiday detector may need to be adjusted in specific areas (example: near high voltage power lines). 4
SURVEYING THE WELDED CONDUCTIVE BACKED GEOMEMBRANE PANEL FOR LEAKS BY SPARK TESTING AS PER ASTM D7240 STEP 1. Connect the wide brush electrode to the holiday detector. STEP 2. Lay the grounding pad on the geomembrane (intimate contact) and hold the electrode. Ensure that the grounding pad and the electrode are within the limits of a panel s seams. If the soil/ under layer is conductive, it may connect the panels together, and the system may work even if the grounding pad and the electrode are not on the same panel. However, it is not recommended to make that assumption, as the conductivity of soils varies a lot. STEP 3. Walk the whole surface of each panel. Make sure that the electrode is touching the geomembrane on the full width. A hole in the hollow of a wrinkle cannot be detected if the electrode is not in direct contact with the geomembrane in that hollow. Even if the length of the electrical arc can reach up to 2 inches, we cannot assume that a hole will be detected 2 inches away from the electrode. Marking of the pin hole The wide brush electrode is too far from the pin hole It is easier to perform the spark test when there are no wrinkles. It is suggested to monitor the environmental conditions and choose the appropriate moment to perform the test. For this reason, it is recommended to do the spark test in the morning, when there is no more morning dew. When you need to move the grounding pad, stop walking. It will reduce the chances to of having false alarms. Each time, make sure it is in intimate contact with the geomembrane. Dust or debris may generate false alarms. It is easier to perform the spark test on a clean geomembrane. It is recommended to verify the cleanliness of the brush electrode periodically. 5 Patches can be inspected using the spark test, with the exception of the extrusions.
STEP 4. If the holiday detector beeps/sparks, find the defect under the electrode. Going backward and forward, changing the angle of the electrode will help locating the hole. While doing this, if the alarm did not trigger again, it was a false alarm. NOTE: To avoid false positive signals, do not cross the seams with the electrode. TESTING OF THE GEOMEMBRANE BELOW THE WELDING FLAP STEP 1. Testing beneath the flaps of welded seams should be completed in accordance with industry practices for non conductive backed geomembranes. The spark tester cannot be used for testing beneath the flaps since the the edges of the geomembrane are nonconductive Seam ADDITIONAL NOTES: The non conductive smooth edges are 6 inches wide. Hence, when welding two sheets of the geomembranes together, if the sheets are not aligned perfectly, the overlap may be too big. The excess overlap may have to be trimmed off to weld the two geomembrane pieces properly. Extra care should be taken not to trim off too much material when trimming the overlap. Trimming off more than 6 inches of overlap will remove the non conductive smooth edge completely, and welding will commence into conductive material. If the welding machine has been calibrated using non-conductive with non-conductive, when overlap greater than 6 inches is cut off from the edges, there may not be sufficient welding pressure to squeeze out all the conductive material and the welds might be deficient. It is therefore recommended to calibrate the welding equipment at the start for conductive on non-conductive. It is also important to note that smooth conductive backed geomembranes also have the smooth non conductive edges, as such, the notes above will apply to both smooth and textured conductive backed geomembranes. 6