Testing of Firewater Distribution Systems

Testing of firewater distribution systems is accomplished to determine if the condition of system is adequate to support a WCCE need for firewater. The condition of piping, leaks, existence of closed valves or sediment, operability of valves and monitors, etc., should be determined annually. 

Typically a network of firewater systems mains is provided in a facility that form loops. These can be segregated into sections or legs and the performance of each can be determined by flow test. Flow tests release quantities of water that are measured and graphed. Performing an initial acceptance baseline test and recording the results from year to year can portray the performance of the firewater system and projections of the useful life of the system can be determined. 

The following is a generic test procedure that may be used to perform a flow performance of fire water distribution systems. 

Determine which fire main is to be analyzed. Within this segment select the hydrants that are the most remote on the system from the source of supply. (Most remote is intended to mean the most remote hydraulically and the selected hydrants may not be the most remote physically). A test hydrant and flow hydrant(s) are identified. The data collected will refer to the test hydrant. The flow hydrant is the next downstream hydrant(s) from the test hydrant. 

It is imperative that the water in the mains is flowing in one direction only during the test (i.e., from the test hydrant to the flow hydrant). In the case of looped and gridiron mains, the water may be flowing in two directions and then issuing from the flow hydrant depending on the particular test being undertaken. 

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