Problem 10.68 Water at 20°C flows through the 20-mm-diameter galvanized iron pipe such that it discharges at C from the fully opened gate valve B at 0.003 m³/s. P=998.3 kg/m³ and = 1.00 (106) m²/s. Use 1.11 1 the equation == -1.8 log 6.9 3.7 Re 3 m 1 m 1 m B 20 mm 1 m '05m Part A Determine the required pressure at A. Include the minor losses of the four elbows and gate valve.