Project Overview: As part of a maintenance project, the conductive/defective isolating joints (IJ) in the Wallbach and Lostorf areas were replaced. This measure was necessary because the existing insulating joints had become conductive and therefore had to be replaced to ensure operational safety.

Work Performed:

1. Insulation of the section: The affected section of approximately 13 km in Wallbach and approximately 15 km in Lostorf was isolated by closing the line valves. This allowed the work to be carried out safely without affecting the rest of the network.
2. Pressure Relief and Gas Removal: After insulation, the gas from the section was pumped until a residual pressure of 0.2 barg was reached. The remaining gas was burned off by flaring.
3. Inertization and Purging: To ensure complete gas-free conditions, a nitrogen cushion was introduced into the depressurized line. The line was then flushed with air until gas-free conditions were confirmed.
4. Replacement of Isolating Joints: The defective isolating joint was precisely cut out and lifted out of the line with a crane. The new isolating joint was inserted into the line by using a crane and welded in place.
5. Recommissioning: In the next step, the empty pipe section was first filled with a nitrogen cushion and then slowly filled with gas. After pressure equalization, the line valve was opened, and the section was recommissioned.

Conclusion: The work was successfully completed, and the affected sections are now fully operational. The replacement of the isolating joints has significantly improved operational safety in this area. A big thank you goes to everyone who contributed to the successful completion of this project.