The necessity to carefully manage water supplies has led to the introduction of water abstraction controls across many parts of the globe. These controls may apply to applications where water is being drawn and distributed for purposes such as drinking water, industrial usage or irrigation.
Using ABB’s WaterMaster electromagnetic flowmeter to measure water abstraction. Image Credit: ABB Measurement & Analytics
Abstraction controls can deliver two major benefits: Firstly, limiting the amount of water that can be drawn from a singular source helps to limit any associated environmental damage, such as depletion or, where water is drawn from a watercourse, harm to aquatic life.
Secondly, carefully measuring the amount of water that is extracted facilitates better management and conservation of existing stocks.
The Application
Water can be drawn from a variety of sources, including reservoirs, rivers, streams and underground aquifers. Where abstraction controls are in place, users will typically hold a license to draw a particular quantity of water from a specific location over a set period of time and for a distinct purpose.
Therefore, it is necessary to quantify and record the amount of water abstracted in some way to make sure that consumption remains within the prescribed limit.
Purposes of abstraction controls:
- Improved management of water resources, including effects of abstraction on the environment
- To check that the abstractor is adhering to the terms of their abstraction license
- To facilitate accurate calculation of annual charges
- To acquire a clear overview of how much water is available for other uses after the licensed abstraction amount
- To help deliver an informed assessment of overall demands, which can then be communicated to the government or other supervisory authorities for action
There are a variety of flowmeters suitable for measuring water abstraction, including mechanical, ultrasonic and electromagnetic technologies. Selecting the right flowmeter for the task in hand depends on a number of factors, including the accuracy and repeatability desired as well as the characteristics of the installation.
For instance, when abstracting water from a river or stream, the presence of pebbles and sediment can quickly damage and even completely destroy a mechanical meter. When abstracting water, the salinity of the water can lead to rapid wear out a stainless steel flowmeter, which necessitates careful consideration of the materials of construction.
The Challenge
As the metered values can be applied to bill the abstractor and to evaluate the overall quantity of water available, it is critical that any flowmeter in use has the capacity to offer the levels of accuracy and repeatability required.
Moreover, it must also be able to withstand the rigors of the application, specifically where there is the presence of high levels of sediment or other non-ideal conditions.
With moving parts that are prone to wear and tear, mechanical meters can suffer rapidly reduced accuracy, leading to either under or over-registration of flows.
Additionally, the fact that mechanical meters must be periodically recalibrated, tested and repaired means that they have to be taken out of the application, meaning users must replace the meter with a temporary device or pause abstraction until the meter is reinstalled back into the line.
Ultrasonic flowmeters demonstrate some issues which make them unsuitable for water abstraction applications. In particular, transit time meters can struggle to handle flows with high levels of particulate matter, which necessitates the use of a filter or strainer.
Both transit time and Doppler meters can also be impacted by velocity profile distortions, requiring from 10 to 40 upstream diameters, depending on the intensity of the disturbance.
Also, the turndown of ultrasonic meters is limited to a range of 20:1 to 40:1. Ultrasonic meters can also present complications in installation and set up procedures, especially where absolute precision is required.
A Solution
Electromagnetic flowmeters present ways to overcome these drawbacks. Compared to other flowmeter types, electromagnetic flowmeters offer much better accuracy and repeatability across their service life, with an uncertainty of ±1 % reading or better.
As electromagnetic flowmeters do not have moving parts, they do not experience problems with wear and tear, reducing maintenance and meaning additional upstream strainers to filter sediment are not required.
A choice of flow primary linings grants additional protection against flows with high sediment and allows users to choose from a variety of materials, such as ceramic linings for particularly abrasive flows.
Electromagnetic flowmeters have the capacity to better handle distorted velocity profiles which leads to a reduction in the amount of piping upstream and downstream the meter needs to do.
Recommended arrangement for an abstraction measurement installation. Image Credit: ABB Measurement & Analytics
What can ABB Offer?
ABB’s WaterMaster and AquaMaster electromagnetic flowmeters can deliver the optimal solution for water abstraction applications. Both flowmeter ranges offer a whole host of sophisticated features and functionality for water measurement techniques.
One of the main features of the WaterMaster is its pioneering octagonal sensor design. By enhancing the flow profile, the octagonal design reduces the upstream and downstream pipe lengths from the point of installation, significantly reducing the cost of placing the meters into new or existing pipelines.
The WaterMaster also comes equipped with onboard verification capability, called VeriMaster, which assures operators of the performance of the meter through consistent self-checking. When paired with ABB’s VeriMaster software tool, it allows operators to print off a verification certificate for regulatory compliance.
All WaterMaster sensors are available in sizes from 10 to 2400 mm (3/8 to 96 in) and are constructed to be rugged and robust to ensure a long, maintenance-free service life even under the most exacting conditions encountered in water and wastewater applications.
The sensors are completely submersible (IP68, NEMA 6P) as an inherent feature, allowing for installation in chambers and metering pits that are prone to flooding. All sizes of the WaterMaster are buriable and easy to install.
WaterMaster is proven to be reliably robust, with unparalleled diagnostic capabilities offering the right information to allow processes to stay up and running. Warning systems and alarms are verified in accordance with NAMUR NE107.
Available in sizes from 10 to 600 mm (3/8 to 24 in), the AquaMaster can be installed everywhere and anywhere, making it the complete network management flowmeter for abstraction and distribution applications.
The meter sensor can be submerged, buried or mounted in a chamber, while the transmitter can be separately installed at ground level up to 200 meters away. This is great for when the sensor needs to be buried under a road or highway.
The AquaMaster has a renewable energy option, meaning it can be installed in the most remote of locations. Adding to the existing battery and mains-powered versions, it can be connected to sources as small as a 5 Watt solar panel or a 60 Watt wind turbine generator.
The AquaMaster is also well-suited to installations with space restrictions requiring zero pipe diameters upstream and downstream.
The meter’s reduced bore sensor means the flow profile is conditioned in the measuring section, which flattens any distortions that could influence either upstream or downstream measurement, as demonstrated via OIML R49 and MID testing.
With no moving parts susceptible to wear and tear, the AquaMaster offers a true fit and forget flow metering solution, with no meter maintenance requirements. Its sophisticated sensor design also means flow pressure loss is minimized as there are no obstructions.
All data that the AquaMaster collects is stored in an integrated data logger, which acquires data on both flow and pressure every 15 minutes. This data can be sent automatically via SMS on a daily basis to a receiver of the customer’s choice.
ABB’s WaterMaster electromagnetic flowmeter offers the ideal solution for water abstraction applications. Image Credit: ABB Measurement & Analytics
Working with both the WaterMaster and AquaMaster flowmeters has been streamlined by the use of ABB’s universal Human Machine Interface (HMI), which has now been implemented across its range of instrumentation products.
Based on Windows™ technology, the HMI makes operation, maintenance and training much easier, thereby reducing the cost of ownership and offering a steady and consistent user experience.
Both flowmeter ranges are also in accordance with OIML R49 type ‘P’ requirements to guarantee the greatest accuracy and long-term performance.
All ABB flow meters have been developed and manufactured in line with international quality procedures (ISO 9001) and are calibrated on nationally-traceable calibration rigs to give the end-user assurance and confidence in both quality and performance.
This information has been sourced, reviewed and adapted from materials provided by ABB Measurement & Analytics.
For more information on this source, please visit ABB Measurement & Analytics.