The top packer is used as a seal when grouting or carrying out water pressure tests in fissured rocks. The packer is placed just below the surface and is tightened against the wall of the hole by a mechanically expanding rubber sleeve.
The central stem is hollow and allows water or grout to be pumped into the borehole, or for various borehole monitoring functions.
The packer operates simply by turning the handle on the top nut and so compressing a length of highly elastic rubber tube between two steel plates. The rubber should be pre-tensioned to be just smaller than the borehole diameter and finally tightened by turning the handle once the packer is positioned.
These packers are custom-manufactured in a variety of diameters to customer requirements and are normally available within 7 days from receipt of order. The customer should specify the diameter of the borehole, length of stem and length of rubber section as required.