What is the difference between "traditional" and "new technology"
In studying flowmeter markets, we found most flowmeters fell into one of two
groups: the “traditional,” that have been around and studied for 50+ years,
and the “new-technology” flowmeters introduced in the second half of the 20th century. We later added
an “emerging technology” category for flowmeters developed in the past 20 years.
technology flowmeters share the following characteristics:
technology flowmeters include differential pressure, positive
displacement, turbine, open channel, and variable area. Despite the
inherent advantages of many new-technology meters, end-user demand for
traditional meter types remains strong.
group, these meters were introduced before the end of World War II.
are less the focus of new product development than new-technology meters.
performance, including criteria such as accuracy, is not at the same level
as the performance of
generally have higher maintenance requirements than new-technology
are slow to incorporate recent advances in communication protocols, such
as HART, Foundation
Fieldbus, and Profibus.
New-technology flowmeters are defined by the following characteristics:
technology was introduced after the end of World War II.
technological ad-vances that avoid some of the problems in earlier
They receive more
focus in terms of new product development than older technologies.
including criteria such as accuracy, is at a higher level than that of
5 . They
are quicker to incorporate recent advances in communication protocols such
as HART, Foundation
Fieldbus, and Profibus than traditional technology
Generally, flowmeters that
fit in the "new technology" category include Coriolis, magnetic,
ultrasonic, vortex, and thermal.
I: Flow Trend Watch. A Look at Recent Developments in New-Technology
Flowmeters - Flow
Control, May 2013
II: Trend Watch. A Look at Recent Developments in Traditional Technology
Control, June 2013
Which types of flowmeters are
most typically used for gas flow measurement?
The main types of flowmeters used for gas flow measurement include:
- Differential Pressure
- Positive Displacement, and
Part 2: The Role of Oil & Natural Gas - Digging Down on the Pros and Cons of Each and Every Possible Solution - Flow Control, February 2013
What is the status of vortex flowmeters? Have there been any technological improvements over the last several years?
One perennial problem with vortex flowmeters has been susceptibility to vibration error.
Vibrations in the line can cause a vortex flowmeter to falsely generate a vortex signal, or to incorrectly read an existing vortex.
Suppliers have responded by implementing software and electronics, including digital signal processing, that have reduced the
susceptibility of vortex meters to interference from vibration.
Another important product enhancement is the introduction of reducer vortex meters. Reducer vortex flowmeters have a reduced
diameter in the center of the pipe, where the bluff body generates vortices. This reduced diameter results in a speeded up flowstream
where the pipe narrows. The introduction of reducer vortex models has simplified vortex flowmeter installation and has improved the ability of
vortex flowmeters to provide accurate measurement at low flowrates.
The growing availability of multivariable vortex flowmeters is also helping boost sales of vortex flowmeters. Sierra Instruments
(www.sierrainstruments.com) introduced the first multivariable vortex flowmeter in 1997. This flowmeter included an RTD temperature
sensor and a pressure transducer. By using information
from these sensors, together with detection of vortices generated, the flowmeter can output volumetric flow, temperature, pressure,
fluid density, and mass flow. Multivariable flowmeters measure more than one process variable, and typically use this information
to compute mass flow. This makes the flowmeter measurement more accurate in changing temperature and pressure conditions.
Vortex Flowmeters - Positioned Well for More Widespread Use Going Forward - Flow Control, December 2012
We've always installed turbine meters. What product enhancements are offered for these traditional meters?
Turbine meter suppliers have made technology improvements to enhance reliability. Many of these improvements have involved
making the moving parts—a traditional source of concern regarding maintenance and repair—more reliable. By making the ball bearings
out of more durable material, such as newly developed ceramics and synthetic sapphires, turbine suppliers have been able to add
significantly to the life of the bearings. This is important, since some customers select new-technology meters over turbine meters simply
because turbine meters have moving parts that are subject to wear.
Other product enhancements that are available today include the new “dual-rotor design” being promoted by
Cox Instruments (http://www.cox-instruments.com/) and other
manufacturers. The dual-rotor design increases the effective operating range of turbine meters in the
smaller line sizes. This innovation specifies that the two rotors turn in opposite direction, with the first rotor being upstream
from the second and acting as a flow conditioner. Flow is then directed back to the second rotor. The rotors are hydraulically
connected, and will continue to turn as the flow decreases even at very low flowrates. This innovation has enhanced turbine
flowmeters’ suitability in low-flow applications. Other recently introduced
improvements include bi-directional flow, self-lubrication, and significantly reduced pressure drop.
Turbine Flowmeters - Technology Upgrades Enhance Turbine Flowmeter Reliability - Flow Control, December 2012
What is the main application for an insertion-mounted ultrasonic meter?
Ultrasonic meters can also be differentiated by mounting type, of which there are three commonly applied to ultrasonic meters:
- Inline (spool piece)
Insertion flowmeters are widely used for flare and stack gas monitoring, as well as for measuring exhaust emissions. Insertion
meters are a good choice in these applications because the stacks and chimneys are often too large in diameter to make an
inline meter practical. Insertion ultrasonic flowmeters compete with averaging Pitot tubes and thermal meters in these applications.
They can also be hot-tapped or cold-tapped into a pipe to make a measurement when meter cost is a consideration and
high accuracy is not required.
Ultrasonic Flowmeters - Measurement Methods & Mounting Options Support a Range of Applications - Flow Control, December 2012
What type of flowmeter is the most accurate?
Coriolis flowmeters remain the most accurate flowmeter, and they are highly reliable with little need for maintenance. Coriolis meters do not place any obstruction in the flowstream, although bent-tube meters can slow down flow velocity. Straight-tube meters have been developed to address this effect and to suit the needs of sanitary applications, which pose an issue for bent-tube meters, which can accumulate material building at their bending points.
Part I: Flow Trend Watch. A Look at Recent Developments in New-Technology Flowmeters - Flow Control, May 2013
is the "paradigm case" method of selecting flowmeters?
"paradigm case" method is a step-by-step method which helps you
to analyze your flowmeter choices, taking into account factors such as
operating principles, advantages, and limitations of each technology. The
steps are as follows:
type of flowmeter is based on a physical principle that correlates flow
with some set of conditions. This
principle determines the paradigm case application for this type of
flowmeter. When selecting a flowmeter, begin by selecting the types of
flowmeters whose paradigm
case applications are
closest to your own.
a list of application
relate to the flow measurement you wish to make.
These conditions may include type of fluid (liquid, steam, gas,
slurry), type of measurement (volumetric or mass flow), pipe size, process
pressure, process temperature, condition of fluid (clean or dirty), flow
profile considerations, fluid viscosity, fluid density, Reynolds number
constraints, range, and others. From
those types of flowmeters selected in Step 1, select those that best meet
these application criteria.
a list of performance
apply to the flowmeter you wish to select. These include reliability,
accuracy, repeatability, range, and others.
From those types of flowmeters selected in step 2, select the ones
that meet these performance criteria.
a list of cost criteria
apply to your flowmeter selection. These
include initial cost, cost of ownership, installation cost, maintenance
cost, and others. From the
types of flowmeters chosen in step 3, select the types that meet your cost
a list of supplier criteria
govern your selection of a flowmeter supplier.
These include type of flowmeter, company location, service,
responsiveness, training, internal requirements, and others.
From the types of flowmeters listed in step 4, select the suppliers
that meet your criteria.
the final step, review the meters that are left as a result of step 4 and
the suppliers listed as a result of step 5.
Review the application, performance, and cost conditions for the
remaining flowmeter types, and select the one that best meets all these
conditions. Now select the best supplier for this flowmeter from those
suppliers listed as a result of step 5.
Learn More: Each
of our research reports discusses in detail the applications,
performances, approximated costs and suppliers of each flowmeter
technology. Please see www.FlowResearch.com
for information on available reports.