DEKOMTE has developed an innovative solution to address persistent issues with the 7F Flex Seal in gas turbine systems. Traditionally, the connection between the gas turbine (GT) exhaust diffuser and the cold, internally lined trough section leading to the Heat Recovery Steam Generator (HRSG) inlet duct utilized an Inconel leaf seal system. This design depended on the flexibility and interference fit of overlapping Inconel plates clamped between the GT diffuser flange and the trough’s cold casing flange. Over time, these leaf seals are prone to leakage and distortion due to continuous flexing, which can compromise the integrity of adjacent equipment. DEKOMTE offered an innovative, integrated solution that gave clearance and reduced heat radiation, to protect the lubricating oil and instrumentation supplies. Learn more about this case study here.

To overcome these challenges, DEKOMTE introduced a solution based on our proven W frame concept, successfully implemented in over 500 GT exhaust systems. This design minimizes temperature gradients, thereby reducing fatigue stress from the hot flange to the fabric clamping area. The integration of the frame flow plate system with the trough results in a fully flexible, cycling solution that maintains gas tightness over extended periods.

A key feature of this approach is the multi-part internal insulation system, combined with a formed fabric solution and external convectors. This configuration effectively manages temperature through the connecting flange, enhancing the system’s flexibility and durability.

DEKOMTE’s experienced technical team can complete the retrofit process in under two weeks. This includes removing the existing seal, performing necessary repairs, and installing the new expansion joint, ensuring minimal downtime for the plant.