Differential Pressure Flow Metering for the Chemical Processing Industry White Paper

Flow measurement is a critical aspect of plant operation in the Chemical Processing Industry (CPI). Users choosing equipment to meter the flow of liquid or gas processes must consider a wide range of factors to arrive at an optimal solution Experience has shown there are significant differences between meter technologies, with each type of device having its own advantages and disadvantages for processing facilities

Common Differential Flow Metering Methods:

• Venturi
• Cone Meter
• Wedge Meter
• Averaging Pitot Tube

In modern chemical plants, personnel need to make faster and better decisions by capturing, managing and analyzing the right data at the right time These facilities rely heavily on flow processes, and thus accurate and reliable measurement techniques are vital to the efficiency and safety of their operations.

Badger Meter, a premier manufacturer of industrial flow meters, has authored an excellent white paper explaining the use of differential pressure flow metering in the chemical processing industry. You can get the white paper at this link.

For more information, visit Thompson Equipment Company (TECO) at https://teco-inc.com or call 800-528-8997 for immediate service.

Remanufactured Flowmeters, Instrumentation & Valves

TECO has the experience, trained technicians, and facilities to remanufacture your equipment to meet or exceed all OEM specifications and performance standards. Send us your old flowmeter, process instrument, or valve and we'll send it back to you as good as new.

Thompson Equipment Company
https://teco-inc.com
800-528-8997

Magnetic Flowmeters for Fracing

Fracing illustration (USGS)

Hydraulic fracturing, or fracing, is the process of exploiting small fissures or cracks in rock layers deep under the earths surface, and increasing their number and size for the purpose of freeing up trapped natural gas. The process includes drilling horizontally in the bedrock and then forcing "frac fluid" into those cracks under very high pressure. The fracturing fluid is made up of water, a special type of sand (referred to as the proppant) and a mixture of chemicals.

Flow measurement is very important in fracing and requires instrumentation with long life and high accuracy.  Frac fluid is a very nasty slurry and it's flow measurement is challenging. Flow instruments are exposed to high pressures, erosive materials and corrosive chemicals.

Frac sand is very erosive and the high pressure and corrosive chemicals complicate things exponentially. Any flowmeter used in fracing applications must not only be rugged enough to withstand these harsh conditions, but the flowmeter must also provide the accuracy required for reliable data reporting to supervisory agencies. Cost-effectively meeting accuracy and longevity requirements for these applications can be frustrating.

Magnetic flowmeters have always appealed to the fracing industry because of their unfettered flow path, availability of sizes and level of accuracy. Their downfall is their longevity. Standard, off-the-shelf magnetic flowmeters don't last in this environment and can't be considered an economically viable choice.

An excellent solution that provides all the the virtues of magnetic flowmeters, and overcomes the longevity and economics issues, are specialized magnetic flowmeters. Referred to as "severe service flowmeters" or "slurry flowmeters", they are designed with components matched specifically to withstand the mechanical and chemical abuse they will see.

Magnetic flowmeters, specialized for fracing, provide all of a "magmeters" desirable features with these critical enhancements:

1. A ceramic sleeved liner made of magnesia partially stabilized zirconia. This ceramic can handle the abrasion and chemical attack with very little degradation.
2. Highly polished, ultra-smooth Tungsten electrodes. The Tungsten provides outstanding wear resistance while the high-polish reduces electrical noise introduced in the electrode circuitry.
3. Special coatings, or paints, to provide exterior protection.

By specifying magnetic flowmeters, specialized for fracing, not only do operators save money through increased uptime and decreased health, safety and environmental risk, but also through reduced costs related to flowmeter purchase and repair.

For more information on fracing magnetic flowmeters, contact Thompson Equipment Company (TECO) by calling 800-528-8997 or visit https://teco-inc.com. 

Magnetic Flow Meters for Abrasive Service

Magnetic flow meters (magmeters) apply Faraday’s Law of Electromagnetic Induction to measure flow. They are specifically designed for conductive fluids like water, acids, caustic liquids, and slurries.

Magnetic flowmeters differ in materials, size, corrosion resistance, pressure and temperature performance. Properly applying magnetic flow meters for abrasive and/or erosive slurry measurement is one of the most challenging applications for plant engineers and maintenance managers to address. The proper combination of design components is critical.

If you have a challenging flow measurement application that involves abrasive or erosive media, contact TECO for assistance. A short conversation with one of our application engineers will save you a great deal of time and money.

Thompson Equipment Company
http://www.teco-inc.com
800-528-8997

Happy New Year from Thompson Equipment Company

Magnetic Flow Meters with Specialized Construction Still the Best Bet for Dredging Applications

Electromagnetic flow meters commonly measure slurry mixture flow on cutter suction dredgers and trailing suction hopper dredgers. These type of flow meters use exposed electrodes and non-conductive flow tubes. Ordinary magnetic flow meter flow tubes  are not designed to withstand the abrasive conditions prevalent in dredging. Standard magnetic flow meter electrodes  are prone to wear, breakage, and polarization requiring frequent re-adjustment. Standard electrode seals may also deteriorate and cause leaks and false readings.

As an alternative, non-invasive (non-wetted) flow meters, such as clamp-on or Doppler ultrasonic flow meters, have long been proposed because of their  ease of installation and maintenance savings. However, testing of clamp-on or Doppler ultrasonic flow meters has never panned out in dredging applications. While there has been limited success on smaller sized diameters, there are few, if any, large diameter dredging pipe application success stories.

Dredging engineers always seek the simplest and most accurate method of measuring slurry flow. Considering this, there is convincing evidence that the use of customized electromagnetic flow meters, specifically designed to stand up to the rigors of dredging, look to be the best overall option.

Dredging flow meter.
(TECO)

Dredging-specific flow meters provide wear solutions that can extend the life of equipment and keep systems at maximum operational levels. Some users report life span up to 10 years.

The dredging modifications include custom engineered ceramic brick or polyurethane liners, 3/4" stainless steel inlet and outlet protectors, independently sealed electrode wells, and field accessible Hastelloy B electrodes.

Thompson Equipment (TECO), a manufacturer of severe service magnetic flow meters located in New Orleans, will "remanufacture" any make or model of electromagnetic flow meter for dredging service. They have decades of experience servicing and remanufacturing instrumentation, and are leaders in building severe service flow meters.

Electromagnetic flow meters have always been appealing for dredging applications in terms of accuracy, resolution, and response time. Their performance problems, caused by the direct and continuous flow of abrasive slurries, are mitigated through specialized construction.  By applying electromagnetic flow meters specifically designed for the application, dredging engineers now achieve excellent reliability, long life and significant reduction in maintenance and operational costs.

Selecting the Proper Flow Meter: Other Considerations

You Get What You Pay For

Engineers and maintenance personnel who purchase flow meters should remember that accurate instruments cost more based on their features and capabilities. It is always better to search for the type of flow meter best suited to a specific application before sacrificing features in favor of lower cost.

Flow meter specifiers should also take the time to examine long-term ownership costs. It may turn out that flow meters with low purchase prices may be very expensive to maintain. On the other hand, a flow meter with a high purchase price may require little or no service, and therefore lower cost of ownership over time. Lower purchase prices do not always represent the best long term, installed value.

Know Your Process

Users need to closely evaluate their overall process conditions, which include flow rates, pressure and temperature, and operating ranges. Be cautious of lower priced alternatives whose operating parameters don't fully support the requirements of the application.

All flow meters are affected to some extent by the process media and the way they are installed. As a result, their real-time performance will often be different from the controlled reference conditions under which they calibrated. There are some general rules that can be applied to flow meters to assist in reducing uncertainty:

• For the lowest uncertainty of measurement, positive displacement meters are generally the best option. 
• Electromagnetic meters provide for the widest flow range and turbine meters are usually the best choice for the highest short-term repeatability.
• Despite their high initial cost, Coriolis meters are ideal for measuring particularly viscous substances and anywhere that the measurement of mass rather than volume is required.

General Selection Concepts:

• In general, flow meters with few or no moving parts require less time and attention than more complex flow meters. 
• Meters constructed with multiple moving parts may malfunction because of dirt, grit or grime present in the process fluid.
• Flow meters with impulse lines can also plug or corrode.
• Flow meters with flow dividers and pipe bends sometimes suffer from abrasive media wear and blockages.
• Swings in ambient temperature may affect the internal dimensions of the flow meter and could require temperature compensation.

Calibration/Recalibration

The need for recalibration of flow meters is generally a function of how well the instrument is paired to its particular application. Should the application be critical, the flow meter accuracy should be checked at frequent, regular intervals. In some instances, mostly non-critical applications, recalibration may not be necessary for a period of years, becuase the application operating parameters never change.

Keep in mind though, that no matter what flow meter technology is chosen, overall system accuracy can never exceed the accuracy of the equipment used to perform the flow meter calibration. With that said, the most precise flow calibration systems on the market employ a positive displacement design. This type of calibrator, directly traceable to the National Institute of Standards and Technology (NIST) via water draw validation, provides total accuracy of at least 0.05 percent.

For more information on flow meter selection, installation, calibration, service, and replacement contact Thompson Equipment Company (TECO). Call them at 800-528-8997 or visit their web site at https://teco-inc.com.