Install Water Control Devices Once packers are removed, they must be thoroughly flushed with water until all grout is cleared and water is clear. Pay particular attention to the ball valves. Ensure there is no grout build-up around the packers and the pipes. Use lubricant in the ball valve to ensure it is free moving. Use grease on threads and around seals to maintain service life. With inflatable packers, it is a good idea to place a small amount of light oil down inside the inflation tube, as this will help to prolong the life of the seals. Once cleaned, inspect the packers and fittings. Use good housekeeping practice to store packers in a manner that ensures they are secure and ready to use for the next grouting rounds. Also ensure their storage location does not interfere with ongoing work flows and poses no risk of trips or falls. Hooks mounted on the walls, to keep packers together and off the ground, is good practice. 2.2.4. Inflatable Packer Inflatable packers are primarily used when collar conditions are of non-uniform size and in weak rock, however they can also be used to stem low volume or low flow water bearing holes. If the ground is in soft rock or there are many fractures, the longer length of rubber on an inflatable packer will give a better seal than the short rubber on a mechanical packer. An inflatable packer also allows you to deploy the packer at any length along the bore hole and grout specific zones as required. They are installed by hand, using an injection pipe to push to the required hole depth. They maintain pressure after inflation via two non-return valves and a rubber pipe sleave; one at the inlet end and one at the outlet end. The outlet end also has a pressure burst disk, which allows the packer to inflate fully in the borehole, before the resin begins flowing through the outlet end. To set the packer in the hole, material is pumped into the inflatable reservoir, which expands to the borehole diameter. Once this diameter is reached, the pressure will continue to increase until the burst disk is breached, allowing the material to flow through the outlet valve. The non return valves and rubber pipe sleave will prevent the packer from deflating during the injection process and once the hole has been completed. Figure: Common Inflatable packers for 48mm and 64mm holes. ▪ Always be aware that when “cracking” a ball valve on a packer to check whether grout has set, there is a high risk of the pressurised release of air/water/grout. ▪ NEVER stand directly behind or in line with a potential pressurised release. Always “crack” the valve very slowly and cautiously. ▪ Ensure other personnel are not at risk of a pressurised release. Inlet Outlet with pressure burst disk
RkJQdWJsaXNoZXIy MjE2NDg3