When an LNG client turned to KLINGER Australia for help with a subsea project, it quickly became a global effort. Project Engineering Manager Nick Evans spearheaded this initiative and joined forces with Technical Lead Scott Whelan of KLINGER UK: at DN1050 (42”) Class 1500#, this gasket would be the largest high pressure class Sentry model to date at over 1.1 meters (43.3 inches) in diameter.
Specialized processes
When manufacturing large diameter gaskets, the process often differs from the usual methods for standard sizes. Holes in this gasket would be too deep to use regular drilling, requiring the team to shift to electrical discharge machining (EDM). This process creates an arc using electrodes and dielectric liquid, and is particularly effective on hard metals. Other specialized processes included a custom fixture built to hold the ring in place for EDM, as well as a second fixture built to weld the rings together.
Of course, designing and building these giant gaskets was only the beginning. Next, KLINGER had to safely deliver them to the job site. Because these custom gaskets are so labor intensive, they are shipped in pairs, to ensure that a spare is ready should any problems occur. They must stay flat, level, and still during their journey across the sea. Special jigs are used to mount the gaskets for the trip, protecting their shape and sealing surfaces.
Large gasket development
With this project completed successfully, KLINGER has refined the logistics of large gasket development, reducing delivery to a highly competitive time frame.
Installation and testing took a total of only 4 hours, with the customer saving an estimated 44 hours of downtime when compared to pressuring the full system using conventional methods. The subsea Pig Launcher Receiver (PLR) was deployed to a depth of 280 meters. With skilled subject matter experts and custom facilities now in place, the project scope will only continue to increase. Current resources support the production of Sentry gaskets up to DN1500/60 in, though the team isn’t ruling out even larger efforts in the future. Nick remarks, “We keep pushing the boundaries with Sentry."
