Method of monitoring of pressure and moisture content in the hollow of a decommissioned pipeline and device for implementation thereof

A method of monitoring pressure and moisture content in a hollow of a decommissioned pipeline comprising:

• installing an indicating cartridge on a decommissioned pipeline filled with gas so that a circulation of gas between a hollow of the decommissioned pipeline and an interior cavity of the indicating cartridge is provided, wherein the indicating cartridge is formed from a transparent material and is filled in the interior cavity thereof with a silica gel, the transparent material of the indicating cartridge allowing for visual inspection of a color of the silica gel;
• connecting a pressure gauge to the indicating cartridge;
• purging the indicating cartridge of gas from the hollow of the decommissioned pipeline;
• within preset time intervals, recording a value of a steady state pressure in the hollow of the decommissioned pipeline from the pressure gauge, wherein the preset intervals comprise daily during a first ten days of monitoring and every fifteen days after the first ten days of monitoring;
• when the recorded steady state pressure deviates from a specified value by a predetermined threshold, concluding that the hollow of the decommissioned pipeline is depressurized and determining a gas moisture content change in the hollow of the decommissioned pipeline by a corresponding change in the color of silica gel in the indicating and;
• when the color of the silica gel in the indicating cartridge has changed to a color outside a specified colorimetric scale limit, concluding that a moisture content in the hollow of the decommissioned pipeline exceeds a predetermined allowable moisture level.