Transient flows in long pipes and conduits conveying water are caused when valves are shut suddenly, or pumps started or shut down quickly. Transient flows can contain large amounts of momentum and kinetic energy, dissipated through heat, damping and elasticity in the pipe walls and surrounding material, or through the generation of cracks and leaks. In practice, many pipes are designed using codes developed for the transmission of steady flows. Testing the design against transient operation is done as a separate exercise; often there is no communication between those conducting the two design checks. The position is further complicated by the lack of EU standards relating to pressure transients. Where transients are mentioned, the hydraulic behaviour of the whole system is ignored.
1. To review and categorise the rules relating to safe design and operation of pipelines from Europe, Scandinavia, USA, Canada and the former USSR;
2. To categorise piping systems into classes and select critical causes of transients;
3. To specify parameters by component for good and baddesign;
4. To specify ground rules for a new EU standard combining transients and steady flow conditions;
5. To specify a methodology for complementing other standards covering transients and leakage in pipelines conveying other liquids.
Work programme: The programme is divided into 6 Work Packages (WPs),which are inter-related but autonomous sets of tasks, with specific objectives and milestones. WP1 is concerned with reviewing all available standards; WP2will collate existing data and develop a suitable common database; WP3 will collect and analyse new experimental data; WP4will analyse published leakage data and collect new leakage data from a specially constructed rig; WP5investigates the interactions between the transients and pipeline flexibility; and WP6 classifies commercially available software and runs a series of software benchmarking tests using the data collected in the other project WPs.
State of progress The majority of the milestones due in the first year have been achieved, enthusiasm for the project remains high and a good working relationship has been developed. The inter-dependence of the WPs has generated a team approach and an understanding of the contribution and responsibility of each partner. Main reviews are completed and the need for additional data identified. New rigs are either built up or being commissioned. The project is on schedule and all partners are committed to making it succeed. 04
Funding SchemeCSC - Cost-sharing contracts
MK12 5QP Milton Keynes
2600 AA Delft
2600 MH Delft
NE1 7RU Newcastle Upon Tyne