AWWA DSS62067

Negative pressures and transient pressures may affect water quality and structuralintegrity of distribution mains. A change in the flow rate in a full distribution main willcause a change in the pressure within that distribution main, either positive or negative.Positive transient pressures exceeding the structural strength of the distribution main willcause damage in the form of rupture or, as is more frequently the case, in the form oflatent damage that results in failure at a later date. Negative pressures may cause damagein the form of structural collapse of flexible distribution main materials, andwaterhammer, and may lead to the intrusion of contaminated groundwater into the watermain. Advances indigital data processing systems have significantly improved our ability to continuouslymonitor and record negative pressures and even the very-short waterhammer event.These improvements have facilitated monitoring for transient pressures under a widevariety of circumstances. Early detection of damaging transient pressure events is nowmore practicable, thus permitting the reduction of damage to distribution mains resultingfrom these events. This paper briefly describes the causes of transient pressures andimprovements in tools available to detect transient pressures. It concludes withsuggestions to civil engineers and distribution main owners regarding what can be done toreduce damages from transient pressures. Includes 4 references, figures.

Product Details

Edition:

Vol. - No.

Published:

09/01/2005

Number of Pages:

9

File Size:

1 file , 640 KB