Concept Water Hammer

Why Concept Water Hammer? We have a range of hydraulic concepts but as a poor cousin of hydrology it is often regarded as an exercise in Bernoulli and little else. Water hammer seldom gets suitable treatment which is neglectful, since in physical structures dynamic loads are not regarded lightly as most building codes will show. Expert systems for water hammer are proliferating and are indeed powerful. They tend to be machines which are activated by the press of a button and where the driver’s features are not visible, intrinsic rather than transparent. It would seem essential to have simple analytical techniques or some clear guidelines to provide a way of developing an overview, even approximate, which lends confidence to the sophisticated solution. There is a need, yet to be satisfied, to specify the dynamic limits of low pressures beside the maximum allowable over pressure for pipe plate thickness. There is a need, yet to be satisfied, to integrate dynamic (water hammer) analysis with the design of an optimum pipe size for a pumping associated system (see Sharp [1]) There is a need, to give priority to management of systems which are at risk due to water hammer, not now, but in years hence, when custom dictates that capacities increase and indeed gravity systems become pumping systems. In truth, optimum (least cost) systems often result when pumping is integrated rather than via a simple gravity flow system. In the same way as an earthquake vulnerability triggers the design approach in a structural analysis problem, so should Concept water hammer, where there is the possibility of air intrusion or 2 phase flow, demanding stringent guidelines for analysis. Is it good management to allow significant air ingress through anti-vacuum valves when the consequences of purging or restart have not been evaluated? When there are competitive water supply authorities having common or associated flow systems, Concept Water Hammer will need to show the degree of liability of one authority to another in the management of their distinct but associated systems. When a mechanical device with specification regarding water hammer is freely available Concept Water Hammer will emphasise the fact that such devices have characteristics that are not unique because they become defined as they are incorporated in a system, that is they are system specific. Examples of valve use and pumping with optimum rules and the limits of accuracy that can be obtained will be discussed. Uncertainties can be assisted by sensitivity analyses in forming a background for Concept Water Hammer.