Author(s): Kristofer Kiste
Linked Author(s):
Keywords: Water Hammer Water and wastewater utilities Knowledge Sweden
Abstract: 1. Introduction and methodology Water hammer is a hydraulic phenomenon occurring in pipe systems when performing operations that change the flow conditions. Thus, valve manipulation or sudden pump changes create pressure waves that propagate in the pipe system. If these waves are of significant magnitude, pipes may burst due to severe over- or under-pressures. Consideration of water hammer events must therefore be given during design stages to avoid pipe damage or failure. A survey conducted in 1980 (Jonsson, 1980) demonstrated that the Swedish water sector broadly lacks knowledge about water hammer, although incidents regularly occurred in Swedish pipe networks. Also, the quantification of water hammer effects was rarely performed since they were judged to be too complicated. The purpose of this study was to follow up on Jonsson (1980) to determine if the current situation has improved in Sweden or if it resembles that of the 1980s. The methodology for the study was based on quantitative research using several different surveys and interviews. One survey was sent to water utilities to assess their proactive and reactive water hammer management, organizational knowledge of the matter, and whether there were leaks or incidents suspected to be caused by water hammer. One survey was sent to the major consulting firms in Sweden to assess the extent of knowledge in the business, both in terms of expertise and general knowledge among utility engineers. One survey was designed for the six major Swedish universities to assess educational opportunities related to the water hammer phenomenon. In addition, interviews were held with four expert hydraulic engineers with extensive experience. 2. Results The study shows that knowledge in Sweden about water hammer is still insufficient in the water and wastewater sector. When designing new piping systems, water hammer assessments are more of an exception than a rule, while most utilities report leaks caused by water hammer. The general knowledge among consultants is low, and water hammer risks are not always addressed in projects involving pressurized networks as a large amount of the utility engineers employed at the consultant firms do not possess sufficient knowledge to assess the possibility of water hammer. The results from the survey sent to academia reported that no university offers individual courses on water hammer, and only three refer to the topic during limited lectures and exercises. At an industrial level, no training programs are given on the topic, implying that people already working in the industry, lack the possibility to learn more about the phenomenon. 3. Key Message A general increase in knowledge is needed throughout the sector to reduce the number of leaks and to ensure a safe work environment for operational staff. Suggestions are made for better collaboration between universities and utilities to ensure the knowledge among utility engineers. An overarching collaboration should be initiated to formulate a methodology for addressing water hammer, so that utilities and consultants have an accessible tool to determine whether simpler water hammer assessments are adequate or if advanced calculations are required. An update of the Swedish industry standard VAV P58 (1988) is also recommended to include a work tool for evaluating water hammer risks.
Year: 2025