TRYCKSLAG I VA-ANLÄGGNINGAR / Waterhammer in Water and Sewage Pressure Pipes
Any change in water flow rate in pipes, regardless of the rate or magnitude of change, requires that the water be accelerated or decelerated from its initial flow velocity. A force is required to change the velocity of he flow and this force occurs as a hydraulic pressure transient in the pipe. The most common cases where waterhammer occurs are when valves close and open fast and at pump shutdowns, especially at uncontrolled power failures. In the article design criteria are formulated to avoid column separation and to get control of other dangerous pressure transients. Different forms of protective equipment are discussed. The use of computor calculation models are good tools when judging the risk of waterhammer. “Complete abstract not presented.”