Theory 094/Energy & Environment /Energy infrastructure
Hydrogen Leakage Is a Seal Ratio
Leakage is discussed in terms of pressure. The seals may set the rate.
Hydrogen leakage from pipelines is set by the ratio of operating pressure to seal tolerance rather than by pressure alone, so a high-pressure line with tight seals can leak less than a low-pressure one with poor sealing.
01The evidence
Leakage rates in gas infrastructure vary widely at similar pressures, and the variation tracks joint quality and seal type.
02The tension
Leak estimation uses pressure and pipe length, which predicts from the driving force and ignores the sealing that sets the leak path.
03The mechanism
Leakage occurs at joints, valves and seals rather than through intact pipe. The rate depends on the pressure difference across the seal and on the clearance the seal allows.
That makes the ratio the determinant, and predicts leakage should track seal quality better than line pressure.
04What this is not
Those models predict from driving force and length. This predicts from sealing, which explains variation at equal pressure.
05Predictions
- P1Leakage should track the pressure-to-tolerance ratio.
- P2Tight seals should beat low pressure.
- P3Seal quality should predict better than pressure.
06Refutation
Leakage tracking pressure at controlled sealing would restore the pressure-length model.
07What it changes
It would change infrastructure specifications for hydrogen.