A gasification reactor comprising a gasifier with a tubular gastight wall arranged within a pressure vessel. The gasification reactor comprises one or more pressure responsive devices comprising a sleeve with a cooled section extending outwardly from an opening in the gastight wall. The pressure responsive devices can, e.g., include a pressure measurement device and/or a pressure equalizer. Method of using a pressure responsive device with such a gasifier, wherein a heat sluice is used formed by a sleeve with a cooled section extending outwardly from an opening in the gastight wall.