Column Separation
Column separation is a phenomenon that can occur during a water-hammer event. If the pressure in a pipeline drops rapidly to the vapor pressure of the liquid, the liquid vaporises and a "bubble" of vapor forms in the pipeline. This is most likely to occur at specific locations such as closed ends, high points or knees (changes in pipe slope). When the pressure later increases above the vapor pressure of the liquid, the vapor in the bubble returns to a liquid state, which leaves a vacuum in the space formerly occupied by the vapor. The liquid either side of the vacuum is then accelerated into this space by the pressure difference. The collision of the two columns of liquid, (or of one liquid column if at a closed end,) results in Cavitation and causes a large and nearly instantaneous rise in pressure. This pressure rise can damage hydraulic machinery, individual pipes and supporting structures. Many repetitions of cavity formation and collapse may occur in a single water-hammer event.
Read more about this topic: Water Hammer
Famous quotes containing the words column and/or separation:
“I got it: Man Without Head Kills Rich Jeweler. What an eight- column spread thatd be on the front page. Why thats the greatest story since Lindbergh flew to Paris. Oh boy, if only it was true.”
—P. J. Wolfson, John L. Balderston (18991954)
“A separation situation is different for adults than it is for children. When we were very young children, a physical separation was interpreted as a violation of our inalienable rights....As we grew older, the withdrawal of love, whether that meant being misunderstood, mislabeled or slighted, became the separation situation we responded to.”
—Roger Gould (20th century)