M-Seals: Solving a Critical Subsea Sealing Challenge

In subsea applications, sealing failure is not an option. When a leading ball valve manufacturer faced persistent leakage issues on valves specified for submarine use, they needed a fast, reliable solution without compromising performance.

The valves’ soft seat seals, manufactured in virgin PEEK, were unable to meet stringent leak-tightness requirements. The only way to achieve compliance was to nearly double the applied torque on the ball, which was an unacceptable approach that risked damaging the valves and preventing them from being placed into service.

As an existing supplier of PTFE lip seals, M Seals was asked to investigate.

Our engineering team conducted an on-site assessment, observing testing under real conditions. The issue was confirmed: sealing performance only improved under excessive torque.

A strip-down inspection revealed a likely root cause. While the material specification was appropriate, the surface finish of the seat seals was suboptimal, potentially creating micro leak paths at the sealing interface.

After obtaining the original drawings while onsite, M Seals was able to recreate the components in our CAD/CAM system within 24 hours. New seat seals were manufactured in Virgin PEEK and a specialist lubricated PEEK grade.

Using in-house tooling and special machining techniques, M Seals achieved a significantly improved surface finish, followed by a superfinishing process to eliminate microscopic imperfections.

Replacement sample seat seals were delivered within two days, assembled into the ball valve and immediately tested.

The virgin PEEK seals exceeded both leakage and torque requirements, delivering improvements of 50% and 10% respectively. The lubricated PEEK variant matched the 50% sealing improvement while achieving a substantial 33% reduction in required torque.

Exceeding the original specifications by such margins represented a significant achievement, enabling the customer to deliver their valves on schedule while eliminating a critical performance risk.

This project highlights the importance of combining material expertise with precision manufacturing and hands-on engineering insight. By focusing on root cause analysis and delivering rapid, high-quality solutions, M Seals helps customers overcome complex sealing challenges quickly and effectively.

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