Question

A pressure gage at elevation 4.8m on the side of a storage tank containing oil reads 34.7 kPa. Another gage at elevation 2.2m reads 57.5kPa. Compute the specificweight, density, and specific gravity of the oil?

Answer 1

Given data:

Elevation of gage -1,

Pressure read by gage -1,

Elevation of gage -2,

Pressure read by gage -2,

Here the pressure is increasing with the decrease of elevation, thus the elevations are measured with reference to bottom. But pressures need to be measured from the surface. Hence let us consider the elevation from surface as ‘x’ for gage -1 and as (x + 2.6) for the gage -2 as the difference between the given elevation is 2.6 m

Now pressure are given by

The pressure difference is given by

Thus the specific weight of the liquid is

The density of the liquid is given by

Thus the density of fluid is

The specific gravity of the liquid is given by the ratio of specific weight of liquid to specific weight of water

Thus the specific weight of liquid is