The mainline grouting process begins by air-testing joints to determine grouting requirements. If a joint fails an air-test, a packer containing the grout is inserted into the line through the manhole. After centering on the joint, the packer is inflated, and grout is injected through the joint connection. The grout creates a hard, impermeable gel around the outside of the pipe. The packer is then deflated, and pulled back for camera inspection, then scraping the remaining gel ring leaving 100% flow capacity in the pipe.