Metal O-Rings and and some Spring Energized C-Rings made from austenitic stainless steels, are not precipitation hardenable.
Heat treatment is mostly not required for Spring Energised C Rings and Metal O Rings. However some demanding applications in Oil and Gas evironment do require heat treatment to prevent material embrittlement.
HTMS Futom recommends to heat treat all non spring energised Metal C Rings. High performance HTMS Futom metal seals will perform better in the heat treated condition.
Metal C-Ring for Internal Pressure (CI) and External Pressure (CE) are designed for high pressure (system pressure energised). They require low bolting load and have good spring back.