Examples of Flexitallic innovative solutions to complex sealing problems
Our Sigma® and Thermiculite® grades, in particular, are used throughout this sector in applications such as towers and tower trays, vessel and railcar manways, heat exchangers, valves, pumps, centrifuges, mixers/reactors, light-duty flanges, and stainless steel flanges.
Flexitallic offers a wide range of innovative products and supporting services for applications within the chemical industry.
|Flexitallic were asked to recommend a product to seal gaseous elemental bromine, an extremely toxic and corrosive chemical. Sigma® 500 at 6.4 mm thick was used to replace a complicated 12mm thick multi-layered PTFE envelope gasket. The size of the bolted connection, with a diameter in excess of 2.2 meters, required that the internal sections of the envelope gasket were dovetailed. As a result gasket handling and installation was both difficult and time consuming and in some instances resulted in seal failure due to envelope misalignment or cracking. The application was made even more difficult as one flange was glass lined the other being made of a titanium alloy; in such situations available gasket stress is severely compromised. A Flexitallic Sigma® 500 gasket was designed using Flexitallic's proprietary Sigma® welding technology resulting in a robust homogeneous, single piece gasket with outstanding handling characteristics, low stress sealing capability and unparallel levels of creep and chemical resistance. Now in successful use for many years; this is just one of many examples of the versatility of the Sigma® range of materials.|
Nitric Acid Plant
|A nitric acid production unit on a Fertiliser plant was experiencing failures of graphite based gaskets on an application of NOx gas at 870°C. This is severely oxidising environment and the gaskets were failing after only three months service life. FlexItallic application engineers were called to find a solution and recommended Thermiculite® 835 filled CGI spiral wound gaskets. Heat treated Inconel 750 windings were used to accommodate the severe thermal cycling experienced in the process. The solution not only extended the service life of the flanges but also eliminated the need to re-torque the gaskets. As a consequence the efficiency of the plant was improved and the gasket inventory was reduced significantly.|