Fw: LMNO Engineering Newsletter - water hammer

From: <Paul>
Date: Mon Jun 23 2003 - 21:45:00 EDT

> LMNO Engineering, Research, and Software, Ltd.
> The fluid flow calculations website: http://www.LMNOeng.com
> 7860 Angel Ridge Rd. Athens, OH 45701 USA (740) 592-1890
> LMNO@LMNOeng.com
>
> Newsletter. Vol. 5, No. 6. June 23, 2003
>
> Water Hammer (hydraulic transient)
> http://www.LMNOeng.com/WaterHammer/WaterHammer.htm
>
> Water hammer (also known as hydraulic transient) is the increase or
decrease in pressure in a pipeline due to rapidly changing a valve or pump setting. The effects can be devastating. Pressure can rise well over twice the steady state pressure in a pipeline due to a rapid valve closure causing a pipe to burst. Water can suddenly vaporize due to opening a valve too quickly. Vaporization occurs when the pressure in the pipe drops to the vapor pressure of water. This can result in severe erosion of pipe surfaces.
>
> Valve operation procedures usually indicate minimum closure (or opening)
times to avoid effects of water hammer. The equations governing water hammer rely on the wave speed of water, mass conservation, and momentum conservation. Wave speed is a function of liquid and pipe properties, including pipe diameter and wall thickness.
>
> Our water hammer calculation computes the maximum and minimum pressures in
each pipe in a pipeline as well as the time and location at which they occur. It is not limited to water; other liquids can be used. The calculation simulates water hammer in a pipeline flowing full, bounded upstream by a large reservoir and bounded downstream by a valve which discharges to the atmosphere. The reservoir is assumed to be large enough to absorb changes in pressure and remain at the same elevation during the transient.
>
> Thank you for your interest in the LMNO Engineering newsletter,
> Ken Edwards, Ph.D., P.E. (Owner/Engineer/Programmer)
> LMNO Engineering, Research, and Software, Ltd.
> http://www.LMNOeng.com LMNO@LMNOeng.com
>
> LMNO Engineering's previous newsletters can be viewed at
http://www.LMNOeng.com/Newsletters/newsletter5.htm
>
>
> You received this free newsletter because you requested it at our website.
If you no longer wish to receive it, send a message stating "Discontinue Newsletter" to LMNO@LMNOeng.com.
>
> (c) 2003 LMNO Engineering, Research, and Software, Ltd.
Received on Mon Jun 23 21:45:00 2003

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