A pipe contains petrol of specific gravity 0.8. The flow is upwards from the point to ‘A’ as shown in Fig. Q.(2c). A differential mercury manometer is connected at the two ‘B’ points and of the pipe which are 0.3m apart. Find the deflection in mercury ‘A’ ‘B’ column if the pressure difference between two points is 18kN/m2 (July 2013,July 2014, jan 2015) Ans: Given (pA- pB) = 18 kN/m2, (ZB - ZA) = 0.3m, Sp.Gr Petrol = 0.8, Sp.Gr. Mercury = 13.6 Equating the pressure about X-X on both limbs of U-tube manometer (p = w×Sp.Gr×H)  (x   0.8  9.81   0.3 0.8  9.81  0.8  9.81 13.6  9.81 pA y) pB y x (pA pB) = 18 = 15.6456 + 125.86 x – x = 0.125m
A pipe contains petrol of specific gravity 0.8. The flow is upwards from the point ‘A’ to ‘B’ as shown in Fig. Q.(2c). A differential mercury manometer is connected at the two points ‘A’ and ‘B’ of the pipe which are 0.3m apart. Find the deflection in mercury column if the pressure difference between two points is 18kN/m2 (July 2013,July 2014, jan 2015) Ans: Given (pA- pB) = 18 kN/m2, (ZB - ZA) = 0.3m, Sp.Gr Petrol = 0.8, Sp.Gr. Mercury = 13.6 Equating the pressure about X-X on both limbs of U-tube manometer (p = w×Sp.Gr×H) pA  (x  y)  0.8  9.81  pB  0.3 0.8  9.81 y  0.8  9.81 x 13.6  9.81 (pA – pB) = 18 = 15.6456 + 125.86 x x = 0.125m
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