Question

Problem 14.43 Water at T = 25°C is drawn from an underground detention tank and discharged into a drain using a 9-in-long pipe and pump (Figure 1). The pipe has a diameter of 100 mm and a friction factor of f = 0.02. The atmospheric pressure is 101.3 kPa. The velocity through the pipe is 4 m/s and h = 5 m. Neglect minor losses. Part A Determine the available NPSH. Express your answer using three significant figures. IVO AQ vec ? (NPSH) Avail = m Submit Request Answer Figure < 1 of 1 Part B (NPSH) red B D 65% 70% 175 6-in. dia. 75% 80% 150 5.5-in. dia. C 86%80% A 125 5-in. dia. Head (ft) 100 w = 1750 rpm 75% 70% -65% 25 bhp 20 bhp 18 bhp 75 50 10 bhp 25

Answer 1

ANSWER:

​​​​​​The answer is as shown in the below handwritten notes:

= 0.1m = 10103 kPa Υ Y Problem 14.43 Answer: - Given data. The fluid is water Length of the pipe (1)=9m. Diameter of pipe (D) - 100 mm Friction factory ()=0.02 he atmospheric pressuse = 101.3 X/02/m7 velocity through the pipe: 4 m/s h=5m. T=25°c Neglect the minor losses Porta- -Avalilable NP.SH:- Pa pv APSH = .-hinha where, Pa = atmospheric pressure = lol.3 kpa = 101.38103 N/m2 V = weight of water 9810 N/m3. PV = vapouer pressure of water at 25°c. Pu= 3.165 kPa = 3-165 x103 ir h = - 5 m he Head loss due to friction f Luz 290 he 0002 x 964² = 1.46 79. m 2x9-81 Xool APSH = 101.3 4/03 3.165X/03 - 5-1-4679 - 10.3263 0.3226 - 5-1-4679 TNPSH 3.536 .9810 9810 m

Parts Required NPSH : Discharge a = Arléax velocity = (0:1*4 30-3142 Q = 497.952 gal/min El milse = from the pump performance curve related to Flow Q. The required Npsit is. 19 ft. The grequired NPSH = 5.791 m NPSH = 5.79 in 15850:3 gallim 1