Ever wondered why a flow meter is required? How it helps? And what's the right process of flow meter installation?

There is an alarming concern that traditional freshwater sources are under stress and competing uses are emergent around the world. Furthermore, climate change impacts advance additional concerns, threatening the security of water supply in the world. This could hinder economic growth, spur massive migration flows, and spark conflict development. To mitigate these issues, an efficient distribution and usage of water is crucial. But before that the precise monitoring of water consumption through the usage of modern, non-defective, water meters is essential to improve efficiency of water distribution and evaluate the effectiveness of demand management strategies.

Smart meters can promote behavioural changes and water conservation by improving information and providing feedback about water consumption to households. Traditional devices for measuring flow include mechanical, electromagnetic, turbine and vortex flow meters. Compared to these devices ultrasonic flow meters have wider dynamic range, higher accuracy, better reliability, require lower maintenance, and do not contain any moving parts.

A number of factors influence maintenance requirements and the life expectancy of flow meters. The major factor, of course, is matching the right instrument to the particular application. Poorly selected devices invariably will cause problems at an early date. Flow meters with no moving parts usually will require less attention than units with moving parts. But all flow meters eventually require some maintenance.

Also Read: Flowmeters With Telemetry

The common causes in which the accuracy of the flowmeter are compromised are only due to incorrect installation, and all pressure based flowmeter are no exceptions to this phenomenon. Here, overall overview is mentioned about the accurate installation of flow meter.

• Ratio of orifice bore diameter to pipe diameter
• Firm support structure to avoid vibrations
• Appropriate sensing tap finish
• Necessary upstream and downstream straight-pipe lengths
• Design and operation of the calibration facilities
• Meter location in relation to the pipe
• Proper plumbing work

Tips To Install A Flow Meter For Best Accuracy

Tip 1: Install the air relief valve in a way to avoid bubbles

A sudden pressure drop in the flow line causes gas to come out of the liquid solution. This is referred to as ‘cavitation’. Items prone to gasification are valves and sharp changes in diameter. Thus, it is important to install the piping in a way to avoid the generation of bubbles. As, entrained air pockets in the pipes can cause excessive head loss and flow reductions, if air is not effectively released. Therefore air release valve is used in the pipeline to free the entrapped air, thus maximising the exiting outflow of water and at the same time ensuring the pipe is not subject to vacuum conditions. Therefore air valve is installed at the particular location to avoid inaccuracies in flowmeter readings.

Tip 2: Check the flow meter positioning

Flow meter installation placement can greatly affect meter performance and accuracy. In order to obtain the maximum operational efficiency, it should be mounted in a position, where it receives the maximum flow, even in the no flow condition.

Tip 3: Flow meter installation with straight length of pipe

Swirl and eddies are large scale disturbances, which are generated due to turbulences in the pipeline. These disturbances causes the problems for pressure based flow element (relying on linear acceleration). The internal processors of the flowmeter, assumes that velocity profile is uniform and symmetrical along the centreline of the pipe. Also in order to avoid the anomalies in the data (partial flow condition), straight length of the pipe is provided.

The minimum straight pipe length provided at u/s and d/s location allows the flow sufficient time and distance to approach stability.

The length of the pipe depends on the pipe diameter and technically provided as per the user installation guidelines.

Tip 4: Elimination of swirl, and developing uniform velocity profile

In some location, where straight run up length are impossible to achieve, another arrangement exists for “training” the uniform velocity profiling in pipeline. Flow conditioners are such arrangements, the purpose of flow conditioners is to act as a buffer between the flow meter and u/s pipeline arrangement. Flow conditioner are responsible for removing the eddies and developing the uniform velocity profile in the flow (necessary for accurate determination).

Also Read: Battery Operated V/S Main Operated Flowmeter1.