CALIBRATION OF ORIFICEMETER

 

CALIBRATION OF ORIFICEMETER

 

AIM: To determine the co-efficient of discharge Cd of Orifice meter

 

EQUIPMENTS AND COMPONENTS:

Orifice filled with a pipe of known diameter, manometer, collecting tank, stop watch.

 

THEORY:

            Orifice is a simple device to measure the flow in a pipe by reducing the flow passage in one section. The pressure difference is created between two sections. The measurement of pressure difference between two sections determine Cd of the Orifice.

            Since the diameter at passage of Orifice is less than that of pipe as the time reaches maximum value the pressure becomes less or pressure tap is provided at this section another pressure tap is provided at a distance of 0.9 to 1.1 times the diameter of pipe from Orifice plate where the pressure is maximum. From the collecting tank we can measure the actual discharge using the formulae.

PROCEDURE:

1.      Diameter of pipe and Orifice are noted down

2.      Air in the manometer pipe is removed by allowing it to pass through the pipe.

3.      The inlet and outlet values are brought to required position.

4.      For a constant discharge the readings of manometer are noted down.

5.      The above procedure is repeated for difference values of discharge.

6.      The graph of Qact v/s H is plotted, value of Cd is calculated