Seal for pump having an internal gas pump

摘要

Pump apparatus having a wear end and a pump end is provided with a seal-pump for preventing liquid being pumped from entering the wear end. An internal pump 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. A seal is provided on a stationary ring of the internal pump which prevents fluid being pumped from contacting working portions of the internal pump.