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.
Investigation of the Water Quality and Condition of Pipe
in Existing Automatic Sprinkler Systems for the Analysis
of Design Options With Residential Sprinkler Systems.
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
corrosion; friction reduction; pipes; potable water;
pressure reduction; residential buildings; sprinkler
systems; water; residential sprinklers; automatic
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.