Flow metering Technology to Help Conserve Water in Arid Climates

Advanced flow meter technology allows for more efficient water demand management

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Advanced flow meter technology allows for more efficient water demand management

By Tim Door

As one of the driest areas in the world, the Middle East is facing massive pressure to manage and conserve its water supplies to meet rapidly escalating demand. Modern flow metering technology can play a significant role in meeting these challenges and is already helping some parts of the Middle East to transform their water network efficiency.

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ABB AquaMaster S electromagnetic flow meter
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With 5% of the world’s population, but just a 1% share of global freshwater resources, Middle East countries face massive issues when it comes to water provision and management. Recent studies by organizations, including The World Bank, have highlighted that many parts of the region are already withdrawing 100% or more of their renewable water resources, with predictions estimating a steady escalating demand for water from 170 billion cubic meters (m3) in 2000, to 228 billion m3 by 2025.

Based on this figure, it’s estimated the regional average water availability for the Middle East and North Africa (MENA) region will be just over 500 m3 per person per year, in stark contrast to the world average of 7,000 m3. Alarmingly, countries such as Jordan and Yemen already have less than this, with a typical average of just 200 m3.

Despite this, existing policies in the region still tend to be directed at increasing supply rather than prioritizing demand management. Investment in outdated networks also is hampered by inadequate cost recovery, with few
mechanisms in place for operators to recoup their costs from end users.

Where managing existing water supplies is concerned, the solutions tend to fall into three main categories, namely improving operator performance, decentralizing responsibility for water networks to the local level or managing water resources more effectively. With many Middle East countries having a serious issue with leaking water networks, there’s also the need to identify both how much water is being lost and where and when these leaks are occurring.

To reach a situation where any of these can be achieved, it’s necessary to first be able to accurately match the amount of water being supplied with the amounts consumed by end users.

Several of the region’s countries have already started to embark on massive investment programmes to bring their water networks up to date. Often, these programmes involve replacement of mechanical flow metering equipment with the latest electronic flow metering technology, which offers a greater level of sophistication for revenue metering and leakage
monitoring.

Why Electronic Meters?

Electronic flow meters have been around in various guises for some time. Yet with the exception of the magmeter – or meters with magnetic flow sensors, they’ve generally been slow to be adopted by the water industry, due mainly to a comparatively higher purchase cost than mechanical metering equipment.

Simple to operate and with a low price tag, mechanical meters have long been seen as an attractive flow metering option. Although apparently more economical in the short term, these meters suffer from serious drawbacks that can lead to operators incurring added costs further down the line.

Foremost amongst these is the steady deterioration in accuracy caused by wearing of mechanical components. Whilst a loss of accuracy of a few percentage points may not appear significant, the potential loss of revenue this represents is becoming of increasing interest as water companies look for ways to achieve more precise flow measurement and improve profitability.

The meter’s total cost of ownership is important to consider when assessing its value. This includes not just the cost of maintaining the meter but of the associated disruption if it’s removed from the line and of sending someone to manually collect information from several meters at a time. This can add up to a significant expenditure over the life of a meter.

Where long term costs are concerned, the arguments in favor of electronic meters are compelling. In most cases, payback on the installation of an electronic flow meter could actually be achieved in a matter of days, as demonstrated by the following example.

Let’s assume we have a mechanical 6” flow meter that’s accurate to within ±2%. This flow meter is installed in line with an average flow rate of 110 m3 per hour, which equates to an annual usage of 963,600 m3. Assuming a cost just for water in Emirati dirham (AED), the United Arab Emirates currency, of AED 4 (US$1.09) per m3, over the course of one year, the inaccuracy of the meter would be losing the operator around AED 57,816.00 (US$15,746) of revenue. Based on this estimate, payback could be achieved within three months.

There also are other areas where an electronic meter can achieve savings. There are no mechanical moving parts that can be subjected to wear and will need to be replaced. This not only ensures the meter’s accuracy is constant throughout its service life, but eliminates the cost, time and disruption associated with removing it from the line for maintenance.

Developments in remote communications technology also mean it’s now no longer necessary for staff to be deployed to read meters or check on their status. Incorporating global system for mobile (GSM) communications technology into flow meters can provide operators with instant access to real-time data and also historical flow data logged by the meter.

Using in-situ calibration equipment, flow meters buried underground or installed in underground chambers can now also be tested from the surface via a laptop computer, enabling easy and cost effective performance checks without interrupting the continuity of water supply. This equipment can also be used to provide a diagnostic health check on the entire flow meter system together with an early warning of any deterioration likely to lead to system failure.

Proof of Benefits

Installations in Kuwait, Jordan and Qatar are providing proof of how installing electronic flow meters can help to transform network efficiency.

In Kuwait, electronic flow meters have been supplied to the Kuwait Ministry of Electricity and Water (MEW) to replace orifice plate meters installed for over 20 years. The flow meters can ensure high accuracy even at extremely low flow rates, are cheap to install and using the GSM communications function, will enable the Ministry to remotely access metering data on a daily basis. Previously, this data had to be collected manually every four weeks from each of MEW’s 400 key metering locations.

MEW’s original scheme of installing a SCADA network to remotely collect data from each flow meter was impractical, due to the cost of installing cabling over such a wide area and because of the lack of available power sources to supply the network. A substantially reduced cost of ownership and a 45% reduction in installation costs with the future option of GSM communications made ABB’s AquaMaster electromagnetic flow meter an obvious choice for this long term project.

A further 22 units supplied to the Amman Water Company in Jordan helped to solve a problem with water hammer, which had rendered useless many previously installed mechanical flow meters. Jordan’s water supply network is frequently shut down for several days at a time to help conserve water. Previously, whenever the supply was restored, residual water in the pipeline was propelled at pressures up to 40 bar g, severely damaging the moving parts of many mechanical flow meters installed throughout the network. Electronic flow meters have overcome this problem. With no mechanical parts, they can handle any sudden surges that occur whenever the water supply is restored.

ABB has also supplied some 600 AquaMasters to the national utility company of another Middle East country. Its strategic plan is to manage its water distribution network more effectively, by comparing readings taken by flow meters strategically positioned throughout its distribution network with those from customers’ water meters to detect leaks more effectively and minimize water loss.

Conclusion

Accurate flow metering is just one of the many water supply and management challenges facing Middle Eastern countries. The ability to derive greatly enhanced measurement accuracy and levels of information, however, makes adopting modern flow metering technology an invaluable starting point for designing strategies to tackle many of these problems.


Author’s Note:

Tim Door is flow product manager for ABB Limited. ABB is a leader in power and automation technologies that enable utility and industry customers to improve performance while lowering environmental impact. The ABB Group of companies operates in about 100 countries and employs roughly 110,000 people. Contact: moreinstrumentation@gb.abb.com or visit
www.abb.com/instrumentation

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