VENTURIMETER TEST RIG

VENTURIMETER TEST RIG

Introduction

A VENTURI METER is a device that is used for measuring the rate of flow of fluid through aย pipeline. The basic principle on which a Venturi Meter works is that by reducing the cross โ€“ย sectional area of the flow passage, a pressure difference is created between the inlet and throatย & the measurement of the pressure difference enables the determination of the dischargeย through the pipe.

A Venturi Meter consists of,

An inlet section followed by a convergent cone,

A cylindrical throat,

A gradually divergent cone.

The inlet section of the Venturi Meter is of the same diameter as that of the pipe, which is followedย by a convergent one. The convergent cone is a short pipe, which tapers from the original size of theย pipe to that of the throat of the Venturi Meter. The throat of the Venturi Meter is a short parallelย side tube having its cross โ€“ sectional area smaller than that of the pipe. The divergent cone of the

Venturi Meter is a gradually diverging pipe with its cross โ€“ sectional area increasing from that ofย the throat to the original size of the pipe. At the inlet and the throat, of the Venturi Meter, pressureย taps are provided through pressure rings.

General Description:

The apparatus consists ofย 

(1) Venturimeterย 

(2) Piping systemย 

(3) supply pump setย 

(4) Measuring tank

(5) Differential manometerย 

(6) Sump

Constructional Specification:

Flow Meters: Consists of Venturimeter of size 25 mm provided for experiments.ย 

The meterย has the adequate cocks also with them


Piping System: Consists of a set of G.I. piping of size 25 mm with sufficient upstream and downย stream lengths provided with separate control valves and mounted on a suitable stand. Separateย upstream and down stream pressure feed pipes are provided for the measurement of pressureย heads with control valves situated on a common Pipe for easy operation.

Supply Pump Set: Is rigidly fixed on sump. The mono block pump with motor, operating onย single phase 220/240 volts 50 Hz AC supply.

Measuring Tank: Measuring tank with gauge glass and scale arrangement for quick andย easy measurement.

Differential Manometer: Differential manometer with 1 mm scale graduations toย measure the differential head produced by the flow meter.

Sump: Sump to store sufficient water for independent circulation through the unit forย experimentation and arranged within the floor space of the main unit.

Before commissioning:

Check whether all the joints are leak proof and water tight.

Fill the manometer to about half the height with mercury

Close all the cocks, pressure feed pipes and manometer to prevent damage and overย loading of the manometer.

Check the gauge glass and meter scale assembly of the measuring tank and see that it is fixedย water height and vertically.

Check proper electrical connections to the switch, which is internally connected to the motor.

Experiments:

The apparatus is primarily designed for conducting experiments on the coefficient ofย discharge of flow meters. Each flow meter can be connected to the manometer through theย pressure feed opening and the corresponding cocks.

While taking readings, close all the cocks in the pressure feed pipes except the two (Downstreamย and upstream) cocks which directly connect the manometer to the required flowย meter, for which the differential head is to be measured. (Make sure while taking reading thatย the manometer is properly primed. Priming is the operation of filling the manometer upperย part and the connecting pipes with water and venting the air from the pipes).

First open the inlet gate valve of the apparatus. Adjust the control valve kept at the exit end ofย the apparatus to a desired flow rate and maintain the flow steadily.

The actual discharge is measured with the help of the measuring tank. The differential headย produced by the flow meter can be found from the manometer for any flow rate.


Leave a Comment