NIST Time|NIST Home|About NIST|Contact NIST

HomeAll Years:AuthorKeywordTitle2005-2010:AuthorKeywordTitle

Investigation of the Water Quality and Condition of Pipe in Existing Automatic Sprinkler Systems for the Analysis of Design Options With Residential Sprinkler Systems. Final Report.


pdf icon Investigation of the Water Quality and Condition of Pipe in Existing Automatic Sprinkler Systems for the Analysis of Design Options With Residential Sprinkler Systems. Final Report. (1597 K)
Alleman, J. E.; Milke, J. A.; Hickey, H. E.

NBS GCR 82-399; 92 p. August 1982.

Sponsor:

National Bureau of Standards, Gaithersburg, MD

Available from:

National Technical Information Service
Order number: PB83-100263

Keywords:

corrosion; friction reduction; pipes; potable water; pressure reduction; residential buildings; sprinkler systems; water; residential sprinklers; automatic sprinkler systems

Abstract:

The objectives of this study were 1) to investigate the potential effect of backflow of sprinkler water into potable water; and 2) to investigate the potential severity of the pressure reduction due to tuberculation in pipes in residential sprinkler systems. The first objective was achieved by physical, chemical and biological analyses of water samples extracted from existing automatic sprinkler systems. The latter objective was accomplished by calculating the Hazen-Williams "C" coefficient associated with a measured water flow rate and pressure differential along a sprinkler pipe. Specific sprinkler systems and locations for sampling were selected to provide a wide variety of conditions for the project relative to the study parameters of pipe material, age, size, and network configuration. In particular, this study attempts to compare the quality of water in sprinkler system pipes with that from the potable water supply for the building. The detailed analyses allow relevant and significant comparisons to be conducted to potentially assess the necessity for backflow prevention in residential sprinkler systems. Comparison of the calculated Hazen-Williams coefficient with the coefficient associated with new pipe facilitates an approximation of the degree of tuberculation in the pipe. This result provides information to assess the severity of pressure reduction as a function of time as affected by the tubrculation and thus to address the useful life of the pipe.