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Water Distribution System Hydraulic Model Calibration and System Evaluation Report <br /> Chapter 5 – Water Distribution System Field Testing <br /> December 2019 <br /> <br /> <br />P05049-2019-000 Page 15 <br /> <br />CHAPTER 5 WATER DISTRIBUTION SYSTEM FIELD TESTING <br />Field data collected for calibration of the water distribution system model included water <br />storage levels, fire hydrant flow tests, and extended pressure tests. During performance of field <br />testing, background data was collected by the SCADA system and included data such as water <br />storage levels, high service pumping rates, discharge pressure, etc. Fire hydrant flow tests were <br />conducted at 24 locations throughout the distribution system. Extended pressure tests were <br />performed at 8 key locations within the distribution system to assist in estimating distribution <br />system pipe roughness coefficients (C-factors). The tasks and protocol followed for performing <br />these field tests are described in further detail in the following sections. <br />5.1 Fire Hydrant Flow Tests <br />One of the most common places to monitor the system and control the testing process is through <br />fire hydrant flow tests. Flow tests performed at fire hydrants provide valuable insight into the <br />calibration of pipe roughness and system demands. Fire hydrant flow tests were conducted at <br />24 locations throughout the City. The hydrant flow testing was performed from June 18th <br />through June 20th, 2019. Appendix A contains a map indicating the location of each fire hydrant <br />test as well as field data sheets showing detailed locations of each fire flow test and data <br />recorded during each test. <br />Two or more hydrants are required to perform a fire hydrant flow test. One hydrant is identified <br />as the pressure hydrant where all pressure measurements are taken, and the other(s) as the <br />flowed hydrant(s), where all flow measurements are taken. When the flowed hydrant(s) is <br />closed, referred to as static condition, the pressure at the pressure hydrant is called the static <br />pressure. When one or more flowed hydrants are open, referred to as the flowed condition, the <br />pressure at the pressure hydrant is called the residual pressure. If one hydrant did not create a <br />large enough drop in pressure, additional hydrants are opened to generate larger flows and <br />associated headlosses. <br />A Telog® Hydrant Pressure Recorder (HPR) was used to record the static and residual pressures <br />at the pressure hydrant. The flow was recorded at the flowed hydrants using a Pollard hydrant <br />diffuser and an HPR. The hydrant diffuser incorporates a pitot gauge connected to a threaded <br />fitting. An HPR is threaded onto the diffuser to record the pressure head. The pitot gauge <br />converts the velocity head associated with the discharge from the fire hydrant into pressure head <br />that is recorded by the HPR. The HPRs were set to sample and record pressure data at 1 second <br />intervals for the fire hydrant flow tests. The pressure head recorded by the HPR is converted <br />into a hydrant discharge rate through the use of an orifice relationship equation. Figure 5-1 <br />shows the diffuser, HPR, and data collector used during the fire hydrant flow tests. Figure 5-2 <br />shows the operation of a flowed hydrant.