English to French Tech/Engineering Engineering (general) compresseur centrifuge

Voici des extraits où ce terme apparaît. Ce principe n'est pas clair pour moi.
If the compressor unit is equipped with an isolation purge buffer between the seals and the bearings, buffer gas must be applied prior to and during operation of the lube oil console to avoid flooding the seal will lube oil, and subsequent seal failure

If conditions exist during shutdown where either buffer gas or process gas can reach saturation conditions, ensure that a dry start-up gas is available for buffering the seals.

Dry gas seal buffer gas should be supplied to compressor skid in a clean and dry form. If gas is expected to be wet, suitable separators need to be installed upstream of the buffer system. Prior to connection of supply piping to the buffer system, lines should be blown down to remove contaminants.

Merci !