APPLICATION: Various chemicals are injected into a deep water well to prevent corrosion, paraffins, hydrates, and scale. The flow rates for the injection are generally very low and need to be metered precisely to prevent under or over-dosing a well.
PRODUCTS SUPPLIED: • VFF series LF03, LF05, and LF15 • HM turbines HM-007 and HM-009/TC-AC/S-EX
CHALLENGE: As oil exploration goes into deeper and deeper water and deeper reservoirs, new challenges arise that put current technology to the test. The newest development is reservoirs that are reaching pressures of up to 20,000 psi. The chemicals need to be injected at a pressure that will overcome the force of the oil flowing up the umbilical.
SOLUTION: By utilizing different technologies available through the TASI Flow portfolio, we were able to offer a solution for this unique chemical injection challenge.
Positive displacement meters from Litre Meter were used for their ability to measure ultra-low flows and their flexible materials of construction that allows for high tensile strength steels exceeding the 20,000 psi pressure requirement. For the higher flow methanol and LDHI applications, the high pressure HM turbine line from AW was used for their ability to measure very non-lubricating fluids while also achieving the desired pressures.
The hazardous area location of these meters also require that all electrical components be hazardous area certified. Because of the close cooperation in development between AW and Litre Meter, as well as all other TASI Flow brands, we were able to offer a single type of user interface for all the meters. Using Litre Meter’s FlowPod transmitter in conjunction with the AW HUB-40EX pickup added a uniformity to the installation of all the meters on the chemical skid.
RESULTS: This is simply one of the first projects heading to locations with reservoirs up to 20,000 psi. In the near future equipment manufacturers in this segment of the market are going to need to produce technology that can keep up with industry needs. TASI Flow’s continuing innovations and ability to customize will allow them to keep pace with the constant change in the O&G production environment. Sign up for FlowSight, the Litre Meter newsletter.
APPLICATION: Fuel and fuel additives test system for final testing of gasoline pumps at Parker Hannifin Manufacturing Germany GmbH & Co. KG in Mainz-Kastel. The pumps are used by Formula 1 racing teams. Every single gasoline pump is tested and qualified on the test system under completely different operating parameters before they are delivered to the racing customers.
CHALLENGE: A test system of high technical complexity was being designed and modelled for unlimited final testing of gasoline pumps for Formula 1 racing customers. To meet the very high demands for quality, the test must cover the entire performance spectrum and provide the optimum testing conditions for the final test. In the area of flow measurement, the task was to specify a highly accurate sensor for the most varied operating parameters. The flow conditions comprised a large spread in temperature and process pressure. This resulted in a change in the viscosity of the fuel. In the first design, turbine flow meters and TRICOR Coriolis mass flow meters were considered. The solution with turbine flow meters required a cascading of several devices to cover the required flow measurement range. Furthermore, different calibration curves needed to be used in order to meet the accuracy requirements.
SOLUTION: TRICOR Coriolis mass flow meters, by contrast, provide multiple technical advantages for this test bed. Flow meters using the Coriolis principle are significantly more accurate, faster and are almost completely independent from the medium properties like viscosity, temperature and pressure – in contrast to some other flow meters. The TCM 0650 covers the entire testing measurement range. With the TRICOR Coriolis solution, Parker Hannifin can cover the required temperature and process pressure range on the fuel test bed with one device. There are no restrictions in regards to fluid, viscosity or accuracy of measurement. Additional components for a cascading measurement (such as needed with the turbine flow meter option) and the associated added expense are eliminated.
CUSTOMER ADVANTAGE: All requirements are met by the broad measurement range of a single TCM 0650. It reduces not only the purchasing costs but also the costs for having replacement devices. Using analogue output signals and modbus TRU interfaces, mass flow, volume flow, temperature and medium density can be read out at the same time on the local display – remote optional. The TCM 0650 is the optimal solution for Parker Hannifin in order to master this challenging measuring task.
APPLICATION: A bayonet-style heat exchanger is used by this customer to heat and vaporise dry liquid Chlorine, to supply multiple reactors at various flow rates with Chlorine gas, at 54°C (130°F) and 180 psig. Pure liquid Chlorine is fed to the vaporizer from a pressurized railcar. The heat source was low pressure steam. The existing system did not control the liquid level in the vaporizer nor the flow of the liquid Cl2, and the vapourizer’s liquid level was limited by equilibrium.
TRICOR PRODUCT SUPPLIED: TCM-28K Hastelloy Coriolis Mass Flow Meter with Integral Transmitter
CHALLENGE: Chlorine has a high coefficient of thermal expansion. Process upsets or momentary shutdowns sometimes resulted in excessive liquid levels, which rapidly led to undesired pressure excursions. There were also cases of low liquid levels, which led to super-heating of the gas. This problem was compounded by the over-sized tube bundle in the vaporiser.
SOLUTION: Since a very small amount of liquid CL2 can lead to serious swings in level, and therefore over-pressure excursions, a highly accurate and repeatable flow meter was required. The customer chose the TRICOR TCM-28K Hastelloy C-22 flow meter. The C-22 alloy features excellent corrosion resistance to Chlorine, and has proven to be superior to C276 for these applications.
RESULT: The new system uses re-circulating hot water as a heat source, rather than steam, and the CL2 liquid level is now controlled via a cascade master and a mass flow control loop.
APPLICATION DESCRIPTION: This lubricant manufacturer now uses two TRICOR Coriolis meters: one measures the individual petrochemical products as they are offloaded into their tank farm, and the second is for batch control as they create products using components from various tanks. The Coriolis meter for batching is used with a Precision Digital Batch Controller and a pneumatic control valve for precise batching.
TRICOR PRODUCT SUPPLIED: TCM-65K Coriolis Mass Flow Meter with Integral Transmitter
CHALLENGE: This customer used multiple hydrocarbon components to create their products, and some components are measured using a manual weight scale. The display was hard to read and the weight scale was unreliable. Additionally, hydrocarbon components were not being measured upon delivery by the customer.
SOLUTION: One 2-inch Coriolis flow meter was placed in the receiving pipeline for measurement of the individual components as they are off-loaded from delivery trucks to the individual storage tanks which provided accurate measurement and billing. Also, by using the batch controller, control valve and Coriolis meter for the batching process, the customer can now dial in the desired amount of individual components and then walk away. These flow meters were also integrated into a local display, a Precision Digital Consolidator which displays values of tank levels and flow rate.
RESULT: The new batching system is set to control the flow rate, totalize the flow, and shut off the flow when the setpoint is reached. The customer is pleased with the accuracy achieved.
We were recently interviewed for a story by our local Chamber of Commerce. This is the result:
Specialist global flow measurement company Litre Meter has come a long way since its conception in 1975.
Set up in the attic of the Wemyss family home – with a calibration rig in the boiler house and a flow lab in the cellar – it was inevitable for a teenage Charles Wemyss to get involved in the family firm established by his father.
Litre Meter provided flow measurement engineering solutions that were ahead of its time and was set up to create one particular product, the Pelton Wheel – designed as a low cost economical meter for flow.
Charles said: “The product line was unusual at the time but now there are far more competitors to it. We still make it and it is still our company logo.”
From age 12 Charles worked in the business in school holidays but despite the cutting edge products and the company’s impressive initial success, he was uninterested in following in his father’s footsteps.
But when his father tragically died in a road traffic accident in 1978, the future of the company lay solely in the hands of Charles and his mother.
And they have done him proud.
Litre Meter has gone from strength to strength and cemented its presence as an international market leader in the flow measurement field, exporting products worldwide.
Now with a 16-strong team and manufacturing and selling from a converted barn in the North Marston countryside, unprecedented sales over the past three years have recently been recognised by Her Majesty the Queen.
Litre Meter was awarded the UK’s highest accolade for sustained business exporting success – The Queen’s Award for International Trade.
Charles, now Litre Meter CEO, tells inbusiness: “We had two very successful years which were recognised in turnover and profit but this was a different recognition altogether. It was barely believable.
“It means as much abroad as it does here as a symbol of achievement. It provides a reassurance for our clients that we are of a certain standard.”
The award recognises continuous achievement, through sustained international trade. Litre Meter were praised for their enviable reputation, excellence in design and manufacturing, investment in British Engineering Excellence and service to the global oil and gas market.
“Our vision has always been to become the most respected specialist flowmeter measurement company in the world and this award reflects our continued commitment to that goal,” said Charles. “My father would have been immensely proud.”
In 2013 and 2014 Litre Meter enjoyed its most successful period ever, winning more orders in two years than in the previous six years combined.
This was driven by an increasing presence in the oil and gas sector, which has led to a substantial increase in export business. Over 65% of Litre Meter’s sales are exports.
Charles said: “There are some solutions we’ve got that no one else can do in the world so there’s no competition. We can do much lower flow rates and much higher pressures than most people and that means we can keep pushing those boundaries and keep innovating – that keeps us competitive.
“Our big market – where we sell more than half of our equipment – goes offshore to the oil and gas industries and they need those higher pressures and lower flows.”
But it hasn’t all been plain sailing in recent years, there have been many challenges along the way.
Charles recalled: “The most difficult time was the recession in early 2009. It was very tough. We had put together an ambitious plan and presented it to the staff in the January. We called it 5 x 14 – to triple our turnover in five years. Two months later we had to reduce all staff to a three day week. The drop in the oil price really affected us then.
“We did get to 5 by 14 – we had £5 million worth of orders in one year.”
A key development that has led to this stupendous success was the manufacture of the Viscous Fluids Flow Meter (VFF), which was originally designed in the mid-80s.
“That’s the product that lifted us and took us to where we are now,” said Charles, who fully took over at the helm of Litre Meter 12 years ago. “It was the right product at the right time. We spent many years refining the product to match the customer’s need, coupled with a worldwide expansion in the market we designed it for and the two things came together quite nicely.”
Litre Meter was sold in 2011 to a large conglomerate, but Charles still sees it as a family firm.
“My proudest achievement is keeping all these guys employed for such a long time. We might now be owned by an enormous American privately owned group but we are still 16 people in a field in North Marston.
“The success we’ve had – and what you don’t realise when you’re in the middle of it – was a big team effort.”
Charles accepted The Queen’s Award for Enterprise from Her Majesty at Buckingham Palace this summer.
ON YOUR CAREER: “I studied mechanical engineering at Sheffield. I graduated in the June/July and was working here at Litre Meter by the September.
“My tutor at Sheffield was head of the flow measurement lab but I had no interest in flow at all. It was the last thing I wanted to do. But I was sick of cleaning the hospital (straight after university) so I rang the MD of Litre Meter and he had just fired his chief engineer.”
DESCRIBE YOUR COMPANY: “We sell and manufacture flow meters and we vary our designs to meet customer requirements. A lot of the jobs are customised, bespoke, made to measure.”
JOINING THE CHAMBER: Litre Meter save money every year by using our International Trade team for export documents. “The service is first class,” said Charles.
We were thrilled to welcome Alexander Boswell, Vice Lord-Lieutenant of Buckinghamshire to our factory last month. He brought with him not only an engraved bowl but also our official scroll. The bowl is engraved with the logo of the Queen’s Award and the official title which is: Queen’s Award for Enterprise- International Trade 2016. We were grateful for a precise speech and official presentation and then Charles Wemyss our CEO said a few words followed by photographs. We were joined by Val Letheren, the Chairman of Buckinghamshire County Council and Jenny Bloom, Chairman of Aylesbury Vale District Council. Many thanks to Joe Bradshaw Assistant Clerk to the Buckinghamshire Lieutenancy who organised all the VIPs so well. The bowl was handed to Alexander Boswell by the Aylesbury Sea Cadet of the Year.
We’re often asked how we managed to achieve such a striking increase in our export sales. Having worked through it we should know this. Looking back we narrowed the factors down to 5:
Firstly, we have a great product, that we keep developing. We target that 25% of our turnover comes from developments in the previous three years. For example, the LF05 size, was introduced in 2012 and soon became our most popular size. More recently, the refreshed VFF range with FlowPod display will be even more desirable.
Secondly, we have built up a terrific sales team, both in-house and with our distribution network abroad particularly in the US and South Korea. Our own Chris Ringer has swung many orders. His skill with the Shah Deniz 2 project was exemplary and 135 meters totalled £1.4m all told through 2 separate customers, aided by our great product and flexibility.
Thirdly, we made a big step forward on Chevron Jack St Malo in 2011/12 which laid the groundwork for meeting the ever increasing engineering challenges.
Fourthly, the Deepwater Horizon accident set new standards and introduced more caution to specifications.
Lastly, economic climate including oil price. That’s stability coupled with historic higher oil prices.
There were just 150 winners in the UK this year, whittled down from an extensive entry list of 600 or more.
DMF (Dimethylformamide, N,N-Dimethylmethanamide, (CH3)2NC(O)H) is a clear liquid organic solvent used in a number of industrial processes, particularly in the manufacture of polyurethane products, pesticides, electrical equipment, pharmaceuticals, and synthetic leathers and fibres. The Tricor coriolis meter proved itself on this technically challenging application using standard equipment.
Pressure: >4 bar
Density: 995 kg/m3
Viscosity: 2 cSt
Flow range: up to 20,000 kg/h / 50,000 kg/h for loading and unloading
Flow range: up to 12,000 kg/h / 25,000 kg/h for product supply for a PU coating agent into the reactor.
TRICOR PRODUCT SUPPLIED:
TCM 028K Coriolis Mass Flow Meters (28,000 kg/hr max)
TCM 065K Coriolis Mass Flow Meters (65,000 kg/hr max)
Charles Wemyss lists 10 reasons why you should – and should not – calibrate your flowmeter
We use the word flowmeter to describe a device that measures the flow of a fluid. Mostly we’re considering gases or liquids in a closed pipe or conduit and we need either the instantaneous flow rate or the total amount of fluid that has passed. There are many varieties of techniques dependent on the fluid being measured and dependent on the flow rate, pressure, viscosity and more. The flowmeters range from miniature positive displacement devices to large electromagnetic or ultrasonic units used for pipes over 3m diameter. The way we garner confidence in the displayed value is through calibration.
Most flowmeters are supplied by the manufacturer with a ‘laboratory’ calibration. In other words, they have been tested in close to ideal conditions. Depending on the meter type, once installed in your process, that original calibration may be valid – or it may not be.
There are a number of key reasons why it should be calibrated:
* To reflect the new, current conditions
* Because some component has a wear factor
* There is an accumulation of dirt or setting product, affecting the sensor
* Because the calibration frequency states it has to be
* Because the results don’t feel right compared to the rest of the process
* The process is producing poor quality product yet the flowmeter seems stable.
The best calibration is that which is performed in situ. Many of the variables are tuned out. The fluid is the same, as is the installation attitude, straight lengths, etc. That’s the precise reason why you should re-calibrate; it gives you that confidence in the device. If in situ is not possible, for example, when the fluid is hazardous or at high pressure then it has to be uninstalled and calibrated elsewhere.
Why shouldn’t it be calibrated?
Clean versus dirty is the first argument for not calibrating your flowmeter. If it comes out of the line dirty and is sent away for calibration then you’d normally expect to ship it clean. The test lab calibrates it in the clean state. However, as soon as you re-install it the process might be depositing dirt back on it. It has been calibrated for a perfect installation and is almost immediately imperfect. In this scenario, calibration is pointless.
Next, it’s hard to compare installation to installation. All calibration laboratories pride themselves on making adequate provisions for calibration, especially good installation practice. If they’re testing a turbine meter, for example, then they should have a long length of correctly sized piping before the meter – and a length after, too. This eliminates swirl, if it’s long enough, to generate a flat flow profile and present optimum conditions to the meter. Most labs have this setup for horizontal installation – so if you have a vertical install, then watch out. Likewise, if you don’t have a long length of correctly sized pipe, or perhaps a connector that necks the diameter down a few percent, then don’t bother. The results they give you will be meaningless.
Next you should ask whether it is the right fluid. Unless your process is running clean water or, maybe a calibration fluid, then your average lab will not be able to calibrate with the same fluid. For some flowmeter types this may not be important. For example, if you fluid is a weak acid with a viscosity of 1.2cP and the meter is an electromag, then the calibration with water will be perfectly valid. Contrarily, if you have 10cP process fluid and it’s a turbine meter then it could be very important that the test fluid is in the 9 to 11cP range to adequately represent the effect of viscosity on meter performance at lower flows.
Traceability is next on the list. If you have been able to clear the hurdles above then it’s important you pick a lab that has the right traceability for you. If your process demands an indication of flow within +/- 4% then there’s little point on getting a UKAS-accredited laboratory with an uncertainty level of 0.22%.
We’re regularly asked ‘how often should it be calibrated?’ Recalibration periods of flowmeters are based on industry standards. In industrial applications, depending on the industry, periods of six to 12 months are recommended. We advise the user to seek out data relating to the process, other components within the process and the usage of the meter. If the measurement is critical then the recalibration should be more frequent than a non-critical, rarely used device. In the absence of any other data we advise an annual check and to vary the future calibration periods depending on results.
If it has remained unused then no recalibration may be necessary, depending on the meter type. It is wise to check that no fluid has settled in the meter that might alter the way the meter works or even cause corrosion. In the event of any doubt then the manufacturer is always your best source of advice.
We are delighted to celebrate being one of the select businesses recognised as winners of the 2016 Queen’s Award for Enterprise – the UK’s highest accolade for business success.
Our award was received for Enterprise in International Trade and was in recognition of achieving significant year-on-year growth of export sales from 2013 to 2015. In turn, this helped us achieve record increases in turnover and profits resulting in a Compound Annual Growth Rate of 48%.
CEO Charles Wemyss: ‘As a very specialist company working on an international basis from the middle of a field in Buckinghamshire it is an outstanding achievement to be recognised at the highest levels for our success.’
Litre Meter was established as a family business in 1975 by the current CEOs father, where it moved to Buckinghamshire in 1978. Today, Litre Meter is recognised as the world’s premier Flow Measurement Specialist, employing home grown talent in a converted barn in North Marston. Our highly engineered products are used in various industries throughout the globe, such as the Oil & Gas sector, where they can be installed on platforms in some of the deepest seas and most arduous environments. We pride ourselves in using local suppliers for our materials, where possible and are proud to be an active part of the UK’s engineering heritage.
Notes for Readers
249 Queen’s Awards (QA) have been announced in 2016 for outstanding business achievement in the fields of International Trade, Innovation and Sustainable Development. Winners of The Queen’s Awards can expect an invitation to attend a special reception at Buckingham Palace.
QA winners can also use The Queen’s Award Emblem in advertising, marketing and on packaging for a period of five years as a symbol of their quality and success.
The awards are made annually by HM The Queen and are only given for the highest levels of excellence demonstrated in each category.
To find out more about next year’s awards visit the Queen’s Award website.
Litre Meter, based near Buckingham, UK, was established in 1975 and specialises in the custom design and manufacture of instruments for measuring and controlling fluids.
The company has particular expertise with offshore and sub-sea flow measurement and has supplied flowmeters for these applications throughout the world. The company’s VFF flowmeter was developed specifically for the petrochemical industry.
Litre Meter also pioneered the development of the Pelton wheel flowmeter, an accurate and versatile technology that has since been used across many industries to measure a variety of low viscosity liquids at both low and high flow rates.
Since 2011 Litre Meter has been part of the TASI Group of companies which includes AW-Lake, KEM and TRICOR.
Whilst exhibiting at the Aberdeen Exhibition Centre in 2015 we were asked by Offshore Europe TV to explain what our meters were and how innovation kept Litre Meter thriving. This is the off-the-cuff response by our CEO, Charles Wemyss:
When specifying flowmeters how does size affect meter selection?
Can you specify the available pipe length? Some installations are very limited on installation length and meter selection can be pivotal. Assume that the number straight lengths before and after the meter (but, see below) isn’t relevant for the moment and all meters are available: If there’s only 1 diameter of straight pipe then the PD meter is probably the Number 1 choice. There’s likely very little room so larger meters like the Coriolis, which is a ‘bulky’ technology, are too long, even if they, too, need no straight lengths: that’s not strictly true but that’s another story entirely.
Width: Does the unit have to fit in a narrow space? Perhaps there’s a wall one side -the meter can’t overhang that side, but is it then facing the right way?
Does the installation space enable the unit to be provided with a local display – which is facing the right way? or will it need to be a remote mounted version?
Is there access for maintenance? Is that all important termination panel just in front of you or is it tucked beyond a stem in a dingy corner of the installation. How good are you at holding a mirror?
If it’s remote mounted – how far away can the display be? ie. what’s limit on the length of cable?
If it’s remote mounted – is that panel mount, wall mount or post mount? Any special mounting considerations like weight, panel size, panel thickness?
Height If it’s not a length or width then height might be an issue. Perhaps the meter can be/ needs to be installed upside down? Maybe there’s a bunch of pipe in close proximity.
Are there weight limitations? On vehicle and aerospace installations the weight can be an overriding factor in meter selection. Are there weight reduction regimes? Changing the connection type or reducing a flow meter size or changing to a lightweight material can have significant effects on weight. A threaded turbine meter can be a tenth of the weight of a flanged coriolis.
Does the meter type require straight lengths before (and after) the meter? Some meters are better than others. Some are much worse than others. A turbine meter needs a minimum 10 lengths before the meter and 5 lengths after. Orifice plates are meant to have more before depending on prior pipe configuration to ensure swirl is minimised.
What comes before the straight lengths? If its two bends in 2 different planes then that’s a great recipe for swirl. Up to 100 lengths of pipe after that will be required to eliminate the swirl.
What methods can reduce pipe lengths? One valid suggestion is to use flow straighteners or plates. These can be as little as 1 diameter long, but with a pressure loss, knock out some flow profile imperfections. They aren’t necessarily commercially available nor cheap. Perhaps, have a look at another measurement technique?
Do you know your fluid? Is it what you think it is? Is it from a known source?
Viscosity, varies with temperature. Is flow measurement going to be affected by viscosity change due to temperature anyway? Might be if the temperature range is large and it’s a Variable Area meter… Will the fluid be changed through the life of the system, introducing different viscosities; meter choice is important here. Viscosity change over time. due to volatility of light compounds it’s likely, especially if exposed to the atmosphere, that viscosity will increase over time. Possibly if water is leaking into the flow stream or condensation in the process that the viscosity will decrease. Viscosity changes due to pressure. These are known but fairly small changes compared with temperature effects. Viscosity can double between atmospheric pressure and 2,500bar. Specific Gravity, Density. These are often quoted in Material Safety Data Sheets (MSDS). For some flowmeters it’s irrelevant, especially if the measurement principle is volumetric; for others, like VA it’s fundamental. And remember density changes with temperature. In general, if you want a mass flow rate or total then use a mass flowmeter (and vice versa). Thixotropic? A shear sensitive liquid can be tricky for some measurement principles. To preserve the fluid at normal viscosity the rate may have to radically reduced. Typical thixotropic liquids encountered are paints. When stirred they change from a ‘gel’ to a more free flowing liquid. Corrosion issues: chemical compatibility. Perhaps the first property that is investigated in meter selection is the chemical nature of the fluid being measured. Is it going to corrode any of the components or will it react with the materials and change some dimensions or shape? If a table found on the internet indicates that polypropylene is ‘compatible’ with fluid X will it be suitable for some close fitting parts where just a 1% expansion will stop the meter going round. 1% may indicate, to some people, that it is compatible. Build up, formation. Slow or fast deposition on the inside of the pipe and other, more sensitive parts, inside a flowmeter may affect the internal diameter used for rate calculations on velocity based devices or the weight of a rotating part or simply stop a part meshing or rotating. Solids content and solids size. Generally expressed as a percentage, the amount of particulate and the size of that particulate will govern the metering method. And it may not be obviously so. Some of the latest paints have small amounts of additive to give the paint a special quality. These will block a tightly toleranced PD meter or it’s bearings. Filter size. Is it filtered? Is the filter mesh in the filter bowl or has it been removed because it keeps clogging up?! What level of filtration, NAS class, mesh size, is designed in and what level has been achieved. Is it well filtered but then stored in an open container? Lubricity. This parameter is frequently ignored and frequently not known. It can have an effect on some flowmeters. Homogeneous? It’s usually taken for granted that fluids are homogenous i.e. the same consistency at any point. A typical non-homogeneity is air entrainment, perhaps a few bubbles or a stream of bubbles. In extremis, this might be slugs of air passing through. Most flowmeters can’t cope with this phenomena but some make a decent estimation and more than a few will recover after the air passes. Anodic acceleration of corrosion. This problem occurs when the fluid acts in concert with two dissimilar materials in the pipeline – for example, the flowmeter body and the pipework. The measured fluid acts as an electrolyte, depositing or removing material depending whether the materials act as anodes or cathodes. In some instances another wetted part may see accelerated corrosion.
All in all, consult the specialists. www.litremeter.com
Flow gauge, flow indicator, liquid meter, flow meter – they’re all the same thing; depending on the industry they may have different names, but their function remains the same: to measure flow.
In the simplest of terms, a flow meter is a device which is used to measure the quantity and/or flow rate of a gas or liquid as it moves through a pipe. Some flow meters measure the amount of fluid that passes through the pipe in a given time, while others measure the total amount of fluid or gas that has passed through the flow meter. Sign up for FlowSight, the Litre Meter newsletter.
How do flow meters work?
Flow meters consist of three parts: a primary device, a transducer, and a transmitter. As the fluid passes through the primary device, the transducer senses it; the raw signal from the transducer is then sent to the transmitter and turned into a usable flow signal.
Mathematically speaking, a flow meter typically uses the following equations:
Q = A · v – Where the volume of fluid passing through a flow meter is equal to the cross-sectional area of the pipe (A) multiplied by the average velocity of the fluid (v).
W = r · Q – Where the mass flow of fluid passing through a flow meter (A) is equal to the fluid density (r) multiplied by the volume of the fluid (Q).
Different types of flow meter
There are a number of different types of flow meter available, each one suited to a different purpose, but always with the same goal of measuring the flow of a fluid or gas through a pipe.
Positivedisplacement flow meters: As the only meters to measure the actual volume, positive displacement meters work by repeatedly filling and discharging fluids from a chamber. Also known as volumetric flow meters, or rotary piston meters due to the way in which they operate.
Inferential flow meters: These types of meters don’t measure volume, mass, or velocity. Instead they measure the flow of a fluid by inferring its value from other measured parameters such as differential pressure.
Velocity flow meters: The flow of fluid through the pipe is measured by the velocity of the flowing stream in order to determine the volume of the flow.
Mass flow meters: A mass flow meter, also known as an inertial flow meter, measures the flow rate of the mass of fluid as it travels past a fixed point during a specified unit of time.
What type of flow meter do I need?
There is no one-size-fits-all solution when it comes to flow meters. It largely depends on the industry you’re in, and what the flow meter will be used for. Here at Litre Meter we’re the flow meter experts, so we can help you to choose which type will work best for your needs, but here are a few questions to ask yourself before looking into purchasing a flow meter for your company:
What gas or liquid do I want to measure?
What level of accuracy do I require?
What is the temperature and viscosity of the fluid?
Does the fluid flow continuously or intermittently?
Will the meter be mounted in a safe or hazardous location?
What are the minimum and maximum flow rates?
What is the maximum pressure at the location?
What level of pressure drop is allowable?
Is the fluid compatible with the materials used in the flow meter?
Each type of flow meter has a different set of applications and constraints, so the best way to choose the right one is to use the application of the equipment, rather than the technology, to guide you in your choice. Once you know the answers to some or all of these questions speak to us and we can help you to determine which flow meter will best suit your needs.
At Litre Meter, we want to make sure that you get the most for your money when it comes to buying a flowmeter, so we’ve put together our top tips for selecting the right device for you…
Made to quantify the rate that liquid or gas moves through it, flowmeters are required by test and measurement professionals to provide results in a wide variety of applications where accuracy is critical. This includes measurements for familiar household things like heating, ventilating and air conditioning to aerospace and agriculture.
Type of flowmeter
There are different types of flowmeter to suit different purposes and applications. By simply profiling the gas or liquid it is measuring, it’s possible to discover how it behaves when flowing through a pipe. You can then narrow down the choice of device to best cope with the conditions of the application. If you’re unsure about how to do this, get in touch with a professional and they’ll be able to help.
There are a number of different uses for flowmeters, and as we’ve just mentioned, whatever you intend to use it for will affect your range of choice. You must consider temperatures needed, the turndown ratio, whether or not it has to be user-friendly for the workplace, and the type of liquid or gas that it is measuring the rate of. For example, if fluid containing traces of silt or sediment is flowing through the pipeline, we’d suggest that you use an ultrasonic Doppler flowmeter.
It’s really important to take into account the materials involved in the process you intend to carry out with the flowmeter. Some materials are not compatible and this can have an effect on both the fluid or gas quality and the flowmeter’s durability. Check each material separately against a reputable chemical compatibility table, and checking your selection with the manufacturer of the fluid is also a wise idea to avoid any potential problems or issues.
Whilst buying a cheaper device may tempt you by saving you money initially, it could actually end up costing you more in the long run. Don’t let short-term savings sway you and think about it practically; a higher priced flowmeter can be more cost-effective in its quality, its back-up and its durability.
Talking of durability, before purchasing the device, you should find out how long it typically lasts. Ask the supplier about its failure rate or the type of application you need it for. This may have an impact on the price, but by evaluating the total life cost of it, you will most likely find it to be worthwhile.
It’s also important to think of the installation before selecting your flowmeter. Consider exactly where and how it will be installed as this can hugely affect its accuracy and efficiency. You must think about the type of meter and whether it’s affected by any obstructions in the pipeline like joints, bends or valves as these could cause distortions to the flow. This is all worth doing because if the device is installed correctly in a suitable application, it will be more accurate and will ultimately save you money.
If you need help in selecting the best flow meter for the job, our Litre Meter team will be happy to help. Simply get in touch via our Contact Form or give us a call on 01296 670200.
Meeting the requirements of safety standards including safety integrity levels (SIL), pressure equipment directive (PED), positive material identification (PMI), ISO17025 and the control of major accident hazards (COMAH) can help to avoid the potential failure of a critical component which could lead, in the worst case, to a catastrophic failure of a process and loss of life.
There has been increased focus on safety issues in the offshore and process sectors over recent years. We want to make sure that our manufacturing focus is on safety in relation to both the environment and industry trends.
Issues surrounding the environment and hydrocarbon releases, asset aging and life extension drive the focus on safety. We want to be able to help in the process of recognising hazards and reducing risk as well as help engineers to take ownership of risk and asset integrity through proving assertions about the functionality and construction of instruments.
Asset integrity management ensures that the people, systems, processes and resources that deliver integrity are in place, in use and will perform on demand over the asset’s lifecycle.
Being able to prove assertions about the manufacture and functionality of equipment are vital in this process.
That’s why we are seeking the views of design engineers, industry leaders and decision makers across industry.
To take our survey – and perhaps you could win a Kindle – visit http://tinyurl.com/LM-Process or http://tinyurl.com/LM-oil-and-gas and spend just a few minutes answering the questions.
Litre Meter was founded 40 years ago as a manufacturer of industrial flowmeters. Today, the company still manufactures flowmeters, but with a slight shift in focus – more than 80% of its products are designed specifically for the harsh conditions of the offshore oil and gas industry.
The shift towards offshore supplying happened largely due to Litre Meter’s ability to engineer new products, as many offshore oil and gas rigs require custom-built flow measurement solutions for chemical injection; however, the ability to engineer new products has sometimes been a setback for Litre Meter, as the majority of orders would often require custom engineering despite the company’s extensive catalogue of standard products.
Litre Meter defines its company by the strapline, ‘Specialist flow measurement engineering’, representing four of its unique and client-oriented company principles:
Specialist: Litre Meter is a specialist manufacturing company, focusing solely on products for measuring flow, rather than level or pressure.
Flow: its products drill down into the finer flow details, such as flow rate and flow total.
Measurement: its products measure flow accurately – they are not flow switches or flow indicators.
Engineering: although it offers a catalogue of standard products, Litre Meter can engineer bespoke solutions for unique challenges.
The VFF series
Litre Meter’s shift in focus began a little over 25 years ago, when it first adapted a standard industrial flowmeter for use on a North Sea oil rig. The popularity and success of this custom device led to the eventual production of their flagship range: the Viscous Fluids Flowmeter (VFF) series.
The VFF series is hugely popular and very adaptable, but its standard range has still been largely overshadowed by a flood of custom orders – until recently. One of the innovations for the 2015 range of VFFs included a new by-product: the FlowPod. The device itself is two-wire and fully HART compatible, with stainless steel housing. It opens up the popular VFF series to an even wider range of low-flow applications, and gives even the most obscure requirements near-instant access to Litre Meter’s innovative engineering without the need for custom designs.
Introducing the FlowPod
Litre Meter decided quite early on that the FlowPod would be its only supporting instrument, and it has completely transformed the way the VFF range can be used.
Designed as Exi and Exd from the outset, the FlowPod was built in an enclosure small enough to be mounted directly onto the meter body, and gives Litre Meter an innovative method of incorporating extra functionality like reverse flow and redundancy measurement.
For Litre Meter, introducing the FlowPod to the VFF range was a great way to combine multiple design elements, gathered over 30 years of experience, to make an impressive and useful meter with a focus on utility plus weight and size reduction.
The 2015 VFF range includes more than 800 end-user drawings, representing more than 115,000 meter combinations and covering almost every conceivable possibility. While previously, around 80% of Litre Meter’s sales were for custom products, the introduction of the FlowPod means that only 5–10% of meters will now need any extra engineering at all. Most customers can simply access instant PDFs of general arrangement drawings, parts-list drawings and lifting diagrams, together with STEP files, as part of their Litre Meter quotation.
For Litre Meter, this means a faster sales cycle and more revenue; for the customer, it means much faster quotation, production and manufacturing times. 2015 has already been a big year for Litre Meter, and by raising its game and producing a range of meters without equals, it has truly cemented itself as a top-tier supplier of flowmeter technology to the chemical injection industry.
We recently re-designed our popular VFF (Viscous Fluid Flowmeter) range of positive displacement flowmeters. The innovations in VFF technology make it ideal for bespoke flow measurement.
Innovations include a new compact size and design with reduced weight using high strength material specifications for high pressure applications. The new range of meters is suitable for low and high viscosity liquids at pressure ratings from 414 bar right up to 4,000 bar (60,000 psi). The range covers the measurement of fluids from 0.3 centistokes (cSt) to 100,000 cSt and flow rates of 0.0008 l/hr to 16,200 l/hr.
We have over 40 years’ experience in successfully designing and manufacturing bespoke flowmeters for extreme environments for the most demanding industries and applications.
The VFF series has been distilled into one series to meet the specific requirements of chemical injection flowmetering. The new 2015 VFF range uses the same ultra-reliable rotary/oscillating piston technology that Litre Meter has developed and refined over the past 30 years. With one moving part the flow meter is a robust and low maintenance component within a chemical injection system.
The VFF range has a wide of standard options so we can quickly respond to fulfill most chemical injection enquiries. A full drawing package is available detailing every option in either PDF or STEP formats.
Specifying the right meter for a system is now even easier to specify with a new VFF meter software, a step-by-step builder that takes the user through all the meter options available. When the meter has been selected the user can search the Litre Meter database of over 400 general arrangements and parts listing drawings. For more details the user can browse 3D STEP files for the correct meter to download and insert into the skid assembly.
Meters are constructed from 316L stainless steel, Duplex Super Duplex, titanium and 6Mo. Other materials are available on request. Standard connections include NPT, Autoclave, ANSI flanges, Grayloc hubs, Galperti hubs and Techlok hubs. Two wire Exia and 2/4 wire Exd versions are available and 4-20mA, HART7 communications is standard with new pickup sensor capabilities.
Other innovations in the 2015 VFF range include a new rotatable and positionable Exd approved display union, new sensing options with increased reliability, reverse flow detection and increased resolution.
We are excited about the new range. The new compact and lightweight design has been developed specifically for integration within chemical injection skids. Its footprint is further reduced because positive displacement flowmeters don’t require straight lengths of pipe in the system before or after the meter.
We have also responded to industry demands with regard to lifting requirements for offshore by adding lifting eyes manufactured from certified forged material to every meter that weighs 16 kg or more.
We have launched new sensor solutions to complement our revamped range of VFF flowmeters.
Our reed sensor package has been improved and now comes in a 316 stainless steel enclosure which is easy to install within the VFF range. The sensor comes complete with two reed switches that can be set for reverse flow detection or redundancy.
The sensor is tested to one billion pulses and environmentally tested in accordance with BS EN 13628-6: 2006. It is temperature rated to -20 to +80°C and it is available with the two or four wire Flowpod – the new explosion proof flow indication display unit for Litre Meter positive displacement flowmeters.
The non-wetted part has an M6 connector and the sensor is compact and designed for use at high pressures.
The new optional field sensor package comes in the same robust 316 stainless steel housing in order to make the sensors interchangeable with one another. The field sensor enables the output resolution of the VFF meter to be increased by a factor of twelve and it can still detect reverse flow.
As part of part of the TASI group of companies Litre Meter now has new representation in Singapore. A new KEM/TASI Flow office in Singapore has been established with Claus Weihermueller appointed as regional manager of KEM/TASI Flow Asia Pacific & Middle East Operations. Claus has spent the past15 years working in the field of flow metering and has been living and working in Singapore for eightyears. He will promote and further expand the KEM/TASI business in the region, including Litre Meter.