Patent ID: 6969229

Claim:
A sealing system for a centrifugal compressor for processing lethal gases comprising: a compressor casing, a first annular chamber connected to a discharge line terminating in a low pressure outlet collector, sealing means being interposed between the compressor casing and an end flange of the casing including an inner lip seal and an outer lip seal, a second annular chamber between said inner lip seal and said outer lip seal, a third annular chamber upstream of said annular chamber, said third annular chamber being located between an inner ring gasket and an outer ring gasket, a first inert gas line for supplying pressurized inert gas to said third annular chamber, a second inert gas line having a shut-off valve therein for supplying pressurized inert gas to said first and second chambers in response to opening said shut off valve, a first line interconnecting said second annular chamber and a first pressure gauge, a second line connected to said discharge line and interconnecting said first annular chamber and a second pressure gauge, said discharge line being connected upstream of said second line to said first line by a third line having a shut off valve, a control unit for controlling the compressor and connected to said first and second pressure gauges, said control unit being responsive to a rapid rise of pressure detected by said first pressure gauge to cause the compressor to shut down and responsive to a rapid rise of pressure detected by said second pressure gauge to cause the compressor to be shut down.