HTMS recommends to heat treat all non spring energised Metal C Rings. High performance HTMS metal seals will perform better in the heat treated condition.

Heat treatment of super alloys such as Inconel X750 ^®, Inconel 718 ^®, Haynes 214 ^®, will increase the yield strength of the material. This influences directly the seal performances, because of increasing seating load and a better spring back.

The increased seating load will press the soft plating better into the surface irregularities, thereby creating a better seal.

The higher spring back means that the intimate contact between the seal and the mating surface is maintained longer in case of flange deflection. Such flange deflection can be a result of high temperatures, high pressures and/or a combination thereof.

Heat treatment is mostly not required for Spring Energised C Rings and Metal O Rings. However some demanding applications in Oil and Gas environment do require heat treatment to prevent material embrittlement. (Heat treatment according to NACE).

Annealing and heat treatment also improves the seals' resistance against fatigue under cyclic loads. Structural integrity will be maintained for an extended period of time.

HTMS offers age hardening, annealing and solution and precipitation heat treatment. Metal O-Rings and some Spring Energized C-Rings made from austenitic stainless steels, are not precipitation hardenable. These seals can only be supplied in the work hardened condition.

For demanding applications and for temperatures above 400°C, HTMS advises to use high alloy steels only.

Heat Treatment Code Table