A description is given of the procedure followed in protecting the pipe of buried pipe-type cables. The first step in protecting such pipes was to see that a ½-inch thick coating of somastic was applied. After the pipes had been coated and installed, a 500 volt megger was used to determine whether or not the required 10 megohms per square foot of pipe surface resistance had been attained. When irregularities were detected in a section, an interrupted direct current was applied between the ground and pipe and a ground survey was made.
A discussion is given of factors involved in the field application of somastic to pipe welds. It was found that cracking could be minimized by keeping the temperature in the mechanical mixer between 300 and 350 F.
A corrosion problem was created when several hundred gallons of cleaning fluid were lost in the ground adjacent to a manhole in the cable line area. It was decided this solvent could be kept out by treating the concrete walls of the manhole with a Thiokol Latex solution. In addition a Thiokol base material was used as a coating for the somastic-coated pipe in the saturated area. When the pipe was inspected six years later it was found there had been no disintegration of the covering. 5.4.5
