Tests for BP give top rating to Supagraf Premier valve packing
June 27th 2008

Tests in Germany to TA-Luft VDI 2440 emission control requirements show that gas leakage past a set of Supagraf Premier valve packings would not even fill a golf ball in a year.

The tests were carried out by the Amtec laboratory for BP Refining & Petrochemicals, operator of the Ruhr Oel Gelsenkirchen refinery. Targets of the investigation were to confirm TA-Luft leakage rates less than 10-4 mbar.l/(s.m) at sealing system temperatures below 250°C, and less than 10-2 mbar.l/(s.m) at above 250°C, for a set of 56mm OD rings.

The test cycle involved 1000 vertical valve stem movements of 40mm — without live loading on the packing — while sealing helium at 25bar for 24 hours. Leakage measurements after 24 hours at 240°C showed 7.0 x 10-6 mbar.l/(s.m). This is less gas than will fill a golf ball in a year at ambient pressure.

After 24 hours at 400°C the leakage rate was 2.3 x 10-5 mbar.l/(s.m). This is less gas than will fill a tennis ball in a year at ambient pressure. "These results demonstrate that Supagraf Premier very easily surpasses TA-Luft requirements for a high grade valve packing," stated James Walker’s business development manager Brian Milford.

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