HX seal ring DNVGL type approval


The series of TPC HX seal rings has now obtained a type approval by DNVGL to their offshore rules covering the size range from ½» to 48″ (DN15 to DN1200). The certificate can be found online:

The solution is as simple as it is brilliant, based on small adjustment of the standard IX ring groove described in Norsok L-005 and ISO 27509. The Norsok flange IX seal ring standard has sealing grooves with an angle on one side only, with a sealing capacity for internal pressure. This one-sided contact, makes the seal vulnerable for warping during assembly. The TPC HX seal ring has two supported sides which means warping is no longer possible. This is created by simply making an identical angle on the opposite side of the seal groove.

The seal ring has a symmetrical cross-section with an upper and a lower groove and also a “waist” formed by the outer handling groove and an identical groove on the inside which is beneficial to prevent misalignment and makes the ring more flexible. The HX seal has four seal lips, all self- energized. The inner lips are pressure assisted from external pressure and the outer lips are pressure assisted from internal pressure.

Due to the drastically increased robustness in the HX design compared with standard IX, this is not only the perfect solution for deep water applications. Subsea diver assisted assembly operations is one example where the high robustness in the HX design is contribution to a safe operation and a first time leak free joint. Other demanding applications can be the use at extreme temperatures, where the large change in strength, stiffness and thermal expansion in flanges, seal and bolting in going from assembly temperature to operational temperature, calls for a robust and reliable seal design.

The TPC HX sealing solution has successfully been used by many major companies in different sizes and materials, such as;

Shell Nyhamna for onshore process piping, TechnipFMC for flexible risers and subsea spools, NewSubseaTechnology for subsea drilling system, NOV APL for offshore offloading hoses, Siemens for subsea electrical equipment canister, McDermott for offshore riser and Aker Solutions for subsea equipment.

If you interested to know more about the TPC HX seal ring and/ or TPC Compact Flanges, then please feel free to contact us. We would love to come and present our solutions for you.