Research and instance analysis on joint water hammer protection of long-distance water supply system

In the hydraulic transition process of remote and up-and-down water supply project, vaporization and column separation easily occur, which may cause water hammer damage to the pipeline. In this paper, the principle and boundary conditions of air valve and one-way surge tank were analyzed. The numerical simulation of hydraulic transition process was conducted on the calculation model of gas-liquid two-phase water hammer, with a project application given as example. By using the joint protection of air valve and one-way surge tank, together with the protection strategy of two-stage valve closing, the pressure of pump-stopping water hummer was controlled effectively.