Experimental investigation of air pockets in pumping pipeline systems

Abstract

Air in pipelines may cause insignificant to severe operational difficulties. If air pockets remain at high points of pumping pipelines, they can cause problems such as a reduction of the effective pipe cross-section, resulting in an increase of head losses. Air pockets can amplify the maximum peak pressures during transients and cause pipe failure. To study large air pockets located at high points in pumping pipelines, experimental investigations were conducted to corroborate that the flow underneath a large air pocket under pressurized flow conditions can be considered similar to gradually varied open channel flow. The hydraulic grade line at pressurized flow conditions was measured with and without air pockets in the test section of the experimental apparatus to verify its effect on the head losses.