Posts Tagged ‘Differential pressure’

ABB wins new framework with Thames Water

December 7, 2015

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ABB Measurement & Analytics in the UK has won a new multi-million pound framework agreement with Thames Water to supply its biggest ever offering of instrumentation equipment.

The framework will see ABB offering an expanded range of products to its previous supply of pressure instrumentation and electromagnetic flowmeters, with the addition of clamp-on ultrasonic flowmeters and borehole level transmitters sourced through its established partnerships with Katronic and Impress Sensors.

As well as the equipment from Katronic and Impress, ABB will also be supplying thermal mass and swirl flowmeters for use in applications including gas and biogas lines at Thames Water’s sewage treatment and thermal hydrolysis plants (THP) process digesters.

ABB has been a supplier to Thames Water for over 20 years, supplying battery and mains electromagnetic and coriolis flowmeters and gauge, absolute and differential pressure transmitters for use across the company’s distribution network and treatment works. The decision to keep us on board for these products and to award us the extended framework demonstrates Thames Water’s confidence in our ability to offer first class levels of service and product performance.

As the largest water and wastewater service provider in England, with over 13 million customers in London and the surrounding counties, Thames Water has set itself key targets in line with the outcomes focused approach set by Ofwat for AMP6. These include ensuring the continued performance of its water distribution network, minimising interruptions to supply caused by factors such as pressure problems and leakage, and ensuring the continued quality of the potable water supply.

By providing accurate data on conditions from around Thames Water’s distribution network, ABB’s equipment will play a key role in meeting these targets.

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Top Tips for selecting Flowmeters

December 17, 2009

Tony Hoyle, Flow Products Manager, ABB Limited, gives his top tips for selecting the best all round flow system for an application.

 1.    Don’t choose on cost alone

When it comes to selecting a flowmeter, cheapest doesn’t mean best! Though the cheapest might save money upfront, it may potentially cause problems later down the line. 

Ultimately, the most cost-effective installation will be the one where the supplier can offer good technical back-up, independently traceable test facilities, a long and established track record and a reputation for high-reliability products based on sound research and development.

2. Know your flow

A key thing to remember when selecting a flowmeter is that every liquid or gas behaves differently when flowing through the pipeline.

Profiling the flow of a liquid or gas through the pipeline can help to select which flowmeter is most able to cope with the conditions of the application.

 The flow profile of a fluid varies according to whether it is Newtonian or non-Newtonian. Newtonian fluids include homogenised or skimmed milk, water, sugar solutions and some mineral oils. They tend to ‘stick’ to the pipe walls, resulting in the liquid moving more slowly at the sides of the pipe than in the middle.

Non-Newtonian fluids, such as paints, shampoos and yoghurt are harder to predict. The flow of these fluids varies as viscosity changes either with time or due to a change in resistance caused by the collision of two different velocities as the fluid sticks to the pipe walls.

To select the best flowmeter, it’s useful to calculate the Reynolds number of the application. This figure is the ratio of momentum against viscosity and can be calculated by using the minimum and maximum fluid flow and viscosity figures of the application. Once you’ve worked out the Reynolds values, they can then be matched against a flowmeter’s Reynolds range to help pick the one that is best able to meet the demands of the application. 

 3.    Opt for the widest turndown

Turndown is the ratio of the maximum and minimum flow rates a flowmeter can measure within its specified accuracy range. The turndown of a flowmeter is important because it is virtually impossible to know in advance the exact range of flows to be measured. Selecting a flowmeter that offers the widest possible turndown ensures that it can cover all anticipated flow variations.

4.    Pay attention to installation

When selecting a flowmeter, think about where and how the device will be installed, as this can affect both accuracy and efficiency.

Obstructions in the pipeline such as joints, bends or valves in close proximity to the meter can all cause distortions in flow profile, affecting flowmeter accuracy and repeatability. To ensure best results, flowmeters should be installed in locations where there are several straight-lengths of unobstructed pipeline both upstream and downstream of the meter.

5. Pick the flowmeter that offers the best accuracy for the application

It’s important to find out which types of flowmeters are most suited to the application.

6. Complying with the law

Customer and regulatory standards have seen a move towards sustainable and ‘greener’ technologies with certified and approved technologies becoming legislative criteria.

The introduction of MCerts/ EPR is a significant extension of this. The latest step in the legislation is the obligation for all industrial and water treatment companies with a requirement in their EPR permit /consent for discharging effluent to a watercourse or the sea to self-monitor their effluent flows.

Introduced as part of a move to improve the measurement and control of discharge and waste levels from both water utility and industrial companies, the self-monitoring obligation requires operators to comply with the Environment Agency’s MCerts certification scheme.

Under this scheme, companies should be able to demonstrate that they are using the Best Available Technique (BAT) to protect the environment. Where the self-monitoring of effluent flow is concerned, operators are subject to a ±8% uncertainty target for the measurement of total daily volume of effluent discharged. This covers not just the equipment used, but also other factors such as correct fitting and the training of relevant personnel to ensure that an installation is correctly set up, operated and maintained. 

In practice this means that, if there are instruments or systems using a particular technology that have passed all the necessary tests and received an MCerts compliance certificate, operators must use them for new and refurbished installations.

Failure to comply can be construed as a failure of a basic duty of care, potentially leading to fines or even imprisonment in serious circumstances, so it pays to keep up to date.

 7. Ensuring continued accuracy

To ensure your installed flowmeters are continuing to deliver optimum measurements, it is advisable to periodically check their accuracy throughout their service life where possible.

ABB offers a range of in-situ verification services for its electromagnetic flowmeters aimed at ensuring their continued accuracy throughout their lifecycle.

8. Use the same supplier for all your flowmetering equipment

A flowmeter is often only as good as the equipment that sits alongside it. Although there are many suppliers offering ancillary flow equipment, the best way to ensure a completely matched system where all components are fully compatible is to specify everything from a single reputable supplier.

9. Helping you to make the right choice

ABB has a wealth of information to help you choose the best flowmeter for your process. The Flowmeter Selection Wallchart provides an informative explanation of the different flow measurements products available and their suitability for certain processes and environments.

ABB has also launched a series of podcast tutorials, covering all of the key flowmetering technologies, explaining how they work and how to choose the right instrument for a particular application.