By replacing a large, fragile and insufficient graphite gasket with a robust kammprofile in optimum design, Gas Storage Denmark prevents leakages and is now up running again within half a workday when maintenance is needed: 75 percent faster than formerly.
More often than necessary, Gas Storage Denmark experienced leakages in a glycol heater application dehydrating the natural gas when distributed from the two national underground storage facilities. Leakages in such a secondary system are not critical neither to the safety nor the gas supply services, but they cause time consuming maintenance work. Changing the previous gasket was an unhandy job that involved not a few men; a graphite gasket with a diameter of 1.4 meters is quite floppy and easily becomes damaged.
The glycol heater (heat exchanger) works with low pressure and low temperatures up to 200 °C. Besides the unmanageable width, it was obvious that another type of gasket could perform better. The product expert from Betech recommended a customised kammprofile (a serrated metal gasket) with Sigma® 500 facing, a high-end PTFE quality provided by Flexitallic®. No less than 52 flange bolts make it difficult to fit the bolts in ordinary circular holes, why the new gasket was designed with wider oval holes. The technical support embraced other critical parts of the sealing system: All bolts, hex nuts and washers were replaced by new and the flanges were repaired to obtain parallel and even surfaces. Finally, correct bolt mounting and tension of flanges were walked through.
First, repair of flanges, replacement of bolts and a more appropriate type of gasket improves quality of the entire sealing system and extends service life. Furthermore, an intelligent gasket design makes handling and installation quite easier and gives considerably reductions in down time. Maintenance jobs are now quite faster and easier to manage.