Faster installation, longer service intervals and zero leaks
Case
Energy / Utilities
By replacing a large, fragile graphite gasket with a robust kammprofile gasket in an optimal design, Gas Storage Denmark avoids leaks and is now back in operation within half a working day when maintenance is performed. That's 75 percent faster than before.
Application
Heat exchanger
Flange assembly
Energy supply
Natural gas
Process plants
The challenge
Far more often than necessary, Gas Storage Denmark experienced leaks from a glycol heater that separates condensate from the natural gas distributed from two national underground gas storage facilities. Leaks from this secondary system are not critical to safety or the gas supply task, but they do lead to a lot of unnecessary and time-consuming maintenance work. Replacing the previous seal was a laborious job that required quite a few people: Graphite gaskets with a diameter of 1.4 meters are quite unstable and easily damaged.
The solution
The glycol heater (a heat exchanger) operates at low pressure and low temperatures up to 200°C. In addition to the size of the gasket, which was difficult to handle, it was obvious that a different type of seal should do the job better. The product expert from Betech recommended an application-specific cam profile (a grooved metal gasket) coated with Sigma® 500, a high-end PTFE grade from Flexitallic®.
No fewer than 52 flange bolts make it difficult to install the bolts through standard circular bolt holes in the gasket. Therefore, the new cam profile is designed with oval holes to make installation easier. The technical support also included other critical parts of the sealing system: all bolts, nuts and washers were replaced with new ones and the flanges were refurbished to ensure flat, parallel surfaces.
Finally, the correct torque and tightening method was reviewed with the maintenance team.
Added value for the customer
Leaks have stopped and the service interval has been extended considerably after refurbishing the flanges, replacing bolts and using a type of gasket that is more suitable for the application. In addition, an intelligent gasket design makes handling and installation much easier and significantly reduces downtime. Maintenance work can now be completed in a third of the time it used to take.