Comparing the Mag Meter and the NIVUS Pipe Sensor

Some time ago, Water Company Directors invited NIVUS to know how the latter can show savings in AMP 5.

The Story Then Begins…

After seeing the NIVUS pipe sensor, UK Water Company asked, “Could we use your sensor rather than a Mag meter?”, “Yes,” NIVUS replied. “How many £ millions would you like to save by using a proven and efficient solution?”

Engineering and Delivery Managers informed NIVUS about the actual cost of refitting a Mag meter and why they would like to employ NIVUS.

The Measurable Benefits

There are numerous benefits of using the NIVUS solution, such as accuracy, ease of use, time, cost and low carbon footprint. In order to provide a direct comparison to the usual cost and time implications of conventional Mag Meter replacement, water companies usually incur considerable amounts of costs namely over pumping, excavation and associated downtime which often make such projects even more cost prohibitive. Pound for pound, this is a direct cost comparison based upon the actual figures provided to NIVUS.

Data provided by UK Water Company Delivery Managers, and not specific to Anglian Water

Above costs based upon a 300 mm pipe application, but larger savings can be realized on larger applications.

NIVUS Cross Correlation Technology

NIVUS Cross Correlation technology is a patented and innovative ultrasonic flow measurement technique. When reflectors are scanned within the water (minerals, gas bubbles or particles), an ultrasonic impulse is saved as an echo pattern. Additional scans follow milliseconds later. Correlation of all signals allows for the measurement of the flow velocity either in full or partially filled applications and displaying the specific flow profile on the screen.

The NIVUS Pipe Sensor

Fully operational installations and field trials have been running for more than three years with accuracies proven similar to validated alternatives, with zero failures. Velocity measurement accuracy is ±1% which is unparalleled in its field and demonstrates this unit as a realistic alternative to MAG meters.

The meter results are good enough that it will be proposed to be developed into one of the @one Alliance standard products to be used by @one Alliance and Anglian Water.

Peter Caldwell, Jacobs, Part of the @one Alliance working on behalf of Anglian Water

MCERTS Approved

As part of their MCERTS programme Anglian Water has used both the wedge sensor and the insertion flow meter to great effect. Installing the wedge sensor at one of our sites in Bedfordshire proved to be a simple and cost- effective way of measuring flow as an alternative to replacing a weir or installing an electro-magnetic flow meter which would have taken extended periods of time and site disturbance to install.

Oliver Grievson, Flow Compliance & Regulatory Manager, Anglian Water

"The NIVUS solution provided a better solution at a cheaper price with a minimum of site disturbance. Anglian Water has also saved money and hassle in using the Insertion Meter for flow meter verification purposes where a "Time of Flight" meter cannot be used. Both the Wedge and the Insertion Flow Meters have given the Anglian Water MCERTS Programme a valuable alternative to the traditional solutions of using ultrasonic and electro-magnetic flow meters" Grievson added.
 

The Innovation Behind the Product

The Cross Correlation patented technology by NIVUS stands ahead of the competition for accuracy. The pipe sensor (insertion flow meter) has a compact design and serves as a one size sensor for all diameters. It is designed for a low carbon footprint and is perfect for full or partial pipes. NIVUS’ unique extraction tool is developed for easy insertion and removal. It is designed for pipes under pressure and thus allows little or no site disruption in any scenario. When time and cost savings are important as is accuracy of data, the pipe sensor becomes the preferred option for the validation and/or replacement of Mag Meters. Cross Correlation, an ultrasonic measurement principle, received its patented status due to the novel measurement method. The detailed profiling of the entire flow provides the required accuracy, which is made possible with this technique. The transition of each particle is measured to pass the sensor and data is measured in milliseconds, affording a continuous and highly accurate flow profile.

"We saw a potential benefit from using this technology. We worked together to arrange a trial of a NIVUS insertion pipe sensor to directly compare against a new magflow meter. The trial was at Caister WWTW where we developed comparison data for mixed liquor flows to a final settlement tank. The results showed very good correlation. NIVUS were allowed to use this data as part of their application to gain MCERTS approval for their meter – their channel based meter already had MCERTS approval. The data was used to justify the installation of a NIVUS pipe meter as a magflow replacement that arose on a separate project on the works." Said Caldwell.

NIVUS Unique Extraction Tool

The NIVUS Unique Extraction Tool can be easily maintained. It is specifically developed for pipes under pressure, enabling easy insertion and extraction of the pipe sensor without having to shut down the flow.

Case Study

Caister WWTW Anglian Water

To cut into an existing main and fit the latest Mag meter with two valves.

• Over pump
• Excavation of site
• Plant stoppages
• Crane
• 4 workmen
• Days of site disruption
• Total cost £ 52,000

The NIVUS Solution

To drill and tap into an existing main under pressure.

• Strap and fit NIVUS pipe sensor
• 2 workmen half a day
• Total cost £ 9,200

Any site preparation costs not included above.

An @one Alliance briefing note and poster were developed and publicized at a sustainability in design drop in session in September 2012 and were seen / discussed by approximately 100 designers and project personnel. @one Alliance projects for Anglian Water have purchased 10 NIVUS meters in tandem with this development.
 

Peter Caldwell, Jacobs, Part of the @one Alliance working on behalf of Anglian Water

Development and Design

The NIVUS meter was in development for a year and was later introduced in the market in 2008. It was mainly targeted to challenge the Mag Meter market. The meter was initially launched into the German Market and then into the UK Market two years later. It also won the official MCERTS status in 2012, and today it is increasingly being recognized as the preferred solution for the validation and/or replacement of Mag Meters in the UK.

Life cycle costs related to Mag Meter installation and maintenance is relatively expensive. By listening to market requirements, NIVUS identified the potential for a removable and more cost-effective flow measurement device for full and partially full pipes that can match the applications and accuracy of a Mag Meter. The compact design and the robust stainless steel outer casing of the flow measurement device are far easier to handle, especially in confined spaces and suited for diameters ranging from 80 mm.

Located at the very tip, the sensor is the only part to sit in the flow and thus reduces any debris or ragging failures with the added benefit of being self-cleaning. The sensor can be installed to any pipe material, and based on application, can be located at almost any circumference point for an accurate and complete reading.

Based on the NIVUS patented Cross Correlation principle, the pipe sensor does not require calibration. Since it is truly versatile, it can provide flow velocity and/or level accuracy whether mounted, for example, on a boat system for open channel monitoring and a pipe insertion meter.

NIVUS has designed the pipe sensor such that it can be easily connected to the lower priced NFP transmitter, for smaller applications. It also reduces the solution costs. Ease of installation marks the biggest impact of NIVUS product; the comparative installation costs are typically 75% cheaper, which literally saves thousands for the Water Industry. A NIVUS pipe sensor can be fitted in just a matter of hours without causing any interruption to the flow, while the Mag Meters are associated with days of site disruption.

Comparing unit prices of the NIVUS pipe sensor versus the Mag Meter, at 300DN for instance, pound for pound the sensor is slightly higher than a Mag meter at this size. However, the considerable costs saved on a fast and easy installation mean the NIVUS pipe sensor is always the more cost-effective solution on the whole, and provides a far cheaper alternative in terms of labor and material on larger applications.

The sensor is available in standard length sizes of 20/30/40 cm. When access space is limited, extendable rods can be fitted for insertion/removal of sensor using a guide tube. Moreover, NIVUS has made maintenance relatively simple and has developed an advanced extraction tool that allows easy removal and insertion of the sensor for pipes under pressure. Therefore, the process does not have to be interrupted.

The NIVUS pipe sensors are designed to last for a long time. They are easy to use, cost effective, easy to maintain and deliver the reliability and accuracy required by Water Companies. Last but not the least, comparable studies have shown that carbon footprint can be reduced by as much as 80% by using NIVUS pipe sensors over the more conventional Mag Meters.

This information has been sourced, reviewed and adapted from materials provided by NIVUS GmbH.

For more information on this source, please visit NIVUS GmbH.