A 6″ 600 flange connection was fitted with 316L graphite faced Halo Seal and the B7 studs loaded to 70% of their yield point. The flanges were pressurised to the maximum pressure limit for the flange class with no visible leak detected. Further increase in pressure to 20000 kPa did not result in a loss of tightness; it was only when the pressure reached 27000 kPa that a loss in pressure was identified.
Upon removal of the Halo Seal no visible damage of the graphite sealing faces was observed.
The test indicate that the Halo Seal is capable sealing well beyond the full pressure range of Class 600lb flange. Further evidence of the wide range of applications to which the Halo Seal is suited.