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Velocity 3.97 fps <br />Velocity Head 0.24 ft <br />Entrance Loss -protruding - .8 VH 0.00 ft <br />Exit Loss 0.24 ft <br />Hazen Williams C -PVC 130 <br />Friction Loss per 100 ft 1.0674 ft <br />Friction Loss 6.74 ft <br />Total Loss 6.99 ft <br />No Entrance loss <br />for 631' <br />Much less than 22', Reach 2 will not Flow full <br />unless siphon action self starts and reduces <br />water surface in the mine. <br />Conclusion: The apparent capacity of Reach 2 is high. Reach 2 will not flow full, The flowing water will tend <br />to drag the air above the water along the pipe thereby creating a reduced, subatmospheric pressure in the <br />pipe. This reduced pressure may cause the water surface to contact the top of the pipe at intervals. A <br />pulsating Flow capable of damaging the system may result. To avoid this scenario S&G recommends that a <br />vent be added to the high point of the system to provide replacement air and establish atmospheric pressure. <br />Alternatively without a vent, siphoning may start and would eventually reduce the water surface to below the <br />intake causing a break in the siphon followed by filling the mine. Reach 1 will Flow full but will take a <br />minimum water surface of 4768.27' in the mine to provide a capacity of 350 gpm except if siphoning self <br />starts. If siphoning self starts the water surface in the mine will alternately drain to 4755 then fill to 4768.27 <br />resulting in a regular 13.27-foot variation of the water surface. The recommended vent would prevent this <br />reciprocating action. <br />