HEAVY DUTY HIGH PRESSURE METAL EXPANSION JOINT FOR A PETROCHEMICAL REFINERY IN QATAR
Customized Axial Stainless Steel Expansion Joint
CLIENT REQUIREMENT
A leading client for a petrochemical refinery in Qatar wanted us to design and manufacture metal expansion joints.
The metal expansion joints were required to accommodate thermal growth in a boiler exhaust duct system operating at 400 °C and 18 bar(g), spanning the section between the Boiler Steam Drum Outlet and the Economizer Inlet. The client had experienced chronic failure of the previously installed stainless steel expansion joints — with an MTBF of less than twelve months — resulting in significant unplanned downtime.
The stainless steel expansion joint is located between the Boiler Outlet Header and the Economizer Inlet Duct and is one of the most thermally and mechanically demanding positions in the flue gas circuit.
The duct transitions from the boiler pressure part into the heat recovery section and must accommodate the differential thermal expansion between the high-alloy boiler pressure parts and the carbon steel duct structure as well as the vibration transmitted from the boiler burners and FD fan and any minor misalignment.
Temperature
Pressure
Inner Media
Bellow Nominal Diameter
External Environment
STAINLESS STEEL EXPANSION JOINT MANUFACTURED BY US
Based on the initial inspection and detailed visual examination, the stainless steel expansion joint exhibited multiple failure modes :
After evaluating the contributing failure mechanisms, OCELFLEX implemented a redesign of the metal expansion joint to improve durability and extend its service life.
Testing and Quality Assurance
Pneumatic Testing
Hydrostatic Testing
Through a systematic redesign process compliant with EJMA (Expansion Joint Manufacturers Association) Standards, Ocelflex delivered a solution that has now operated without failure for over 28 months since commissioning.
