Expansion Joint Replacement Procedure

The expansion joint replacement procedure mainly includes five steps: shutdown and pressure relief, removal of the old part, cleaning and inspection, installation of the new part, and testing and commissioning. Strict adherence to procedures is required to ensure safety and sealing.

Shutdown and System Isolation

Close upstream and downstream valves to cut off the media supply and ensure the pipeline system is completely shut down.

Empty the media (water, steam, gas, etc.) from the pipeline and confirm the pressure is zero using a pressure gauge.

High-temperature systems must be allowed to cool naturally to below 60°C to prevent burns or thermal stress damage during disassembly.

Implement the lockout/lock-on (LOTO) tag to prevent accidental equipment startup.

Removing the Old Expansion Joint

Loosen connecting bolts or cut welds:

Flange Connections: Use a torque wrench to gradually loosen the bolts in a diagonal sequence to avoid uneven stress and deformation of the flange.

Welded Connections: Cut the welds using an angle grinder or gas cutter, taking care to protect surrounding pipelines from damage.

Carefully remove the old expansion joint, avoiding direct contact with the bellows using a pry bar and preventing damage to the flange face.

After removal, immediately cover the pipe opening with a plastic cap or wooden board to prevent foreign objects from entering.

Cleaning and Interface Inspection

Thoroughly clean the flange sealing surface, using a wire brush and scraper to remove rust, old gasket residue, and oil stains.

Inspect the condition of the pipe interfaces: Check for deformation, corrosion, cracks, or misalignment; if damage is found, repair or replace the corresponding pipe section.

Measure the alignment to ensure that the new expansion joint can be coaxially aligned during installation, avoiding eccentric stress.