Abstract: A seal gas pressure booster system for use with a gas compressor, particularly of the type used for boosting pressure in gas transmission, process or utility industries and which contains pressure about the shaft/casing interface with the use of dry gas seals. Seal supply gas is supplied from the discharge side of the compressor. During normal operation, sufficient head across the compressor exists to supply the necessary flow of seal supply gas against the restrictions provided by the filters, interconnections and components in the seal gas supply system. During startup, or during modes of operation where sufficient head across the compressor does not exist, the pressure booster system increases the pressure of a stream of compressor discharge gas to provide the necessary pressure differential to supply the dry gas seal with a continuous flow of clean, filtered gas.