Question

The pressure at section (2) shown in the figure is not to fall below 50 psi when the flowrate from the tank varies from 0 to 1.0 cfs and the branch line is shut off. Determine the minimum height h of the water tank (note: minor losses need to be considered). 10 ft h All pipe is 6-in.-diameter plastic (€/D = 0), flanged fittings 6 ft Branch line (2) Main 1 line 2000 ft 1000 ft with 10 90-degree elbows and 10 unions

Answer 1

The energy equation between section © & @ Pi + viz t zi Pz + V2 + Z2 + f Į V2 + EKLV? 2g 29 Y 29 ఆ 10+h+6 Zi- Pico i Vi=0; 22=0 ; the Values, we 1 Substituting e get 0+o(10thre) * * 6+16 - fx +[2+ f £ + [ku] 29 79 V2 16 1 ho pe + [1 + foto + Eku] I z r flow rate Q: VA D= 6 ft Q= 1 ft3/s 12 2 1.VXIX ( 1 V = 5.094 ft/s ft/s at 60°F V = 1.21 x10-5 number Reynold's 5.094 la) 12 Re - VO 1:21 x 10-5 Re = 210495.86 cs Scanned with CamScanner

VON at Re = 210495.86 and $ .o fuo.0155 from moody's 'S chart the minor losse Considering :: EKL- (Kuentrance + (к) тее + 15 CKL)elbony 0.5 +0.2 + 15 x 0.3 5.2 U² -16 ho Pz + [1+ f g + Eku] kele :: Y ha 60 x 144 + 62-4 1 + 0.0155 X Ch + 6 [1 +0.0 +600+ 900) +5.21 x (6/12) 16 5.0942 2x32.2 ] h= 0.012462h + 143.72 .: h= 145.534 ft CS Scanned with CamScanner