3. Possible explanations a) The gas is breaking through the liquid seals. b) Stacking of the liquid flowing across the bubble cap trays, forcing the gas through only a section of the tray. 4. Suggested liquid seal improvement’s a) Increase the seal pan outlet weir from 80 mm to 110 mm by adding a strip of steel. The strip should only be welded to the existing outlet weir and mounted flush with the absorber wall. The modification can be done from the PS3 distributor without removing it. b) Reduce the bubble cap 5 seal pan weep hole to diam. 5 mm. c) Inspect the leak tightness of all bubble caps outlet weirs (17 trays). The gap between the weir and the vessel wall should be seal welded. If the gap is not welded and is larger than 2 mm then strips of steel must be welded to the outlet weir to seal it.