Pump with axial dry gas seal.

摘要

Pump apparatus (10) having a wear end (12) and a pump end (14) is provided with means for preventing liquid being pumped from entering the wear end. An internal pump (50,52) is positioned between the wear end and the pump end of sealless pumps to direct small quantities of gas from the wear end to the pump end at a pressure which prevents liquid in the pump end to pass into the wear end.