Determining The Difference In Pressure Between Two Pipes Using The Manometer

Apparatus

• Plastic tubing• Meter stick• Liquid mercury• Two pipes of different energy potential• Pressure gauge meter

A Differential Manometer is used to measure the difference in pressures between two points in a pipe, or in two different pipes.

In its simplest form, a differential manometer consists of a U-tube, containing a heavy liquid, whose two ends are connected to the points, whose difference in pressure is required to be found out.

X

h1 h2

A

B

h3ɣ1

ɣ2

ɣ3

Let,h=Difference of the center of A, from the mercury level on the right limb

Procedure

• Fill some amount of mercury inside the plastic tubing.• Insert one end of the plastic tubing to the

piezometer cock of one pipe, and the other end to the piezometer cock of another pipe.• Open slowly the gate. The pipe with the higher

potential will push the mercury inside the plastic tubing towards the other pipe with lower potential. The surfaces of the liquids will keep on moving until the system is in equilibrium.

• Mark on the side of the manometer stand in level with the liquid surface. This can be done by using plastic leveling hose.• Measure the difference in elevation between the

center lines of the two pipes, the heights of the pipes from the reference and the vertical distance between surfaces of liquid and mercury.• Observe and record he readings of the pressure

gauge meter.• Make a partial sketch of the pipe system and label

the distances and dimensions.

A differential manometer is connected to two pipes as shown in Figure. The pipe A is containing carbon tetrachloride sp.gr. = 1.594 and the pipe B is contain an oil of sp.gr. = 0.8. Find the difference in pressure between the two pipes.

25.16cm