Analysis on pressure-falling phenomenon caused by air chamber in pressured water supply pipe

Abstract

Air tends to accumulate at the vertex or the inflexion place of the pipeline in pressured water supply system. Air chambers will lead to the pressure losing. Research of the air chambers influence will contribute to a more complete and accurate hydraulic calculation. This paper analyzed the pressure-falling phenomenon caused by air chamber in quantificational, deduced two calculation formulas for pressure loss in static state and dynamic state, and discussed application of the formulas in especial states. The research indicate that the water head loss equals height difference between the front and back end of an air chamber, and it is a solution of a quartic equation of one variable in steady-state flow.