Transit Time Differential Ultrasonic Flow Measurement - How It Works

Ultrasonic flow meter, transducer and control unit
Courtesy Flexim

The measure of flow is a pervasive task in fluid process control. There are several differing technologies employed for measuring fluid flow, each with its own set of performance and application attributes that might make it the advantageous choice for a particular operation.

Ultrasonic flow measurement uses several methods for determining the average velocity of a fluid. One of those methods employs the difference in the transit times of ultrasonic pulses travelling with the flow direction and against the flow direction. The flow velocity of the media will offset the transit times between the flow and counterflow measurements. The measured difference in transit times can be used to determine average flow velocity and, with additional processing, mass flow.

Ultrasonic flow meters are accurate and provide repeatable results, making them suitable for custody transfer operations, as well as many other process control applications. Little maintenance is required and the units have no moving parts. Measurement instruments are available with in-line or clamp-on mounting, providing a high level of installation and application flexibility.

The short video below provides a clear explanation of how transit time difference measurement works. Share your flow measurement challenges and requirements with a product application expert, combining your process knowledge with their product expertise to develop effective solutions.

 

Use Nitrogen? How About Generating Your Own Supply?

Nitrogen is used extensively throughout industry

Nitrogen is utilized by industrial customers more than any other gas. In addition to being a part of every living thing on the planet, nitrogen is also the major component of atmospheric air at around 78% concentration.  It is incorporated as part of many compounds used to make a wide range of products. Nitrogen is also used as a cooling medium and as a means to isolate flammable or reactive compounds from oxygen.

There are several methods employed to generate or provide nitrogen, each with certain aspects making them advantageous to a certain range of applications. Convenience, reliability of supply, space, cost, energy consumption, purity, and a host of other factors can weigh on the decision for nitrogen supply.

Parker Balston, a globally recognized manufacturer of gas process equipment, authored a white paper making a case for considering in-house nitrogen generation for industrial processes. The article describes the three prevalent methods for producing highly purified nitrogen gas and compares their impact on the environment, as well as their suitability for users large and small.

The article, included below, is short and very informative, definitely worth reading. When considering your options for nitrogen supply, consider in-house production as a worthy alternative to the delivery of pressurized gas bottles. Share your requirements and challenges with a product application specialist, combining your process knowledge with their product expertise to develop an effective solution.

Comparison of Alternate Methods for Generating Nitrogen for Industrial Processing from Classic Controls, Inc.

Product Integrates Multiple Generator Condition Monitoring Functions in a Customized Unit

Multiple generator monitoring functions consolidated
in a single integrated console.
Courtesy E/One Utility Systems

Electric power generation involves enormous investment in fixed equipment operating at conditions requiring precision control of many variables. The availability of accurate real-time generator monitoring information can be the key element in maintaining precision equipment in good operating condition and avoiding downtime caused by failure.

E/One Utility Systems designs and manufactures a generator monitoring system combining multiple functions into a consolidated unit, fully engineered and coordinated for each application. Each customer can choose to incorporate functions as needed for their installation.

• Generator Auxiliary System
• Generator Gas Analyzer
• Generator Condition Monitor
• Generator Gas Dryer
• Auxiliary Systems

This flexible and cost efficient approach to gas monitoring and control systems for electric power generators capitalizes on the use of pre-engineered modules to reduce installation and on-site engineering burden.

More information is provided in the document below. Share your power generator monitoring and control challenges with product specialists and work together to develop effective solutions.

E/One Gas Station Integrates Multiple Generator Equipment Monitoring Functions from Classic Controls, Inc.

Asset Condition Monitoring Can Reduce Unplanned Outages and Improve Profitability

Model 3500 Rack Mount Monitoring Unit
Courtesy GE Bently Nevada

Lost industrial production and unplanned plant outages can be unbelievably costly.

Asset condition monitoring, as the name implies, is the process of continually monitoring a machine or piece of equipment with the intent to predict mechanical wear or failure point. Key indicators of failing equipment are changing values in vibration, noise, and temperature, all of which are measurable with the right equipment. Monitoring these variables, key indicators of machine operating health, provides valuable data which can be analyzed. By evaluating trends in the data, intelligent systems can provide useful information about the equipment and asset, such as early detection of possible faults or failures. The goal is to take preventative, less costly, measures, rather than clean up after an outright failure.

Continuously monitoring critical asset parameters such as vibration, temperature, speed, and numerous other condition indicators is a proven method for anticipating and preventing mechanical failures—proven in tens of thousands of industrial facilities around the world by delivering tangible benefits such as:

• Improved protection from catastrophic failures
• Better machinery reliability/availability
• Fewer process interruptions
• Enhanced maintenance/outage planning
• Lower maintenance and repair costs
• Longer intervals between outages
• Reduced insurance premiums

Implementation of asset condition monitoring is benefiting manufacturing plants and process industries such as chemical, petrochemical, pulp & paper, power generation, wind turbines, and oil & gas. Not only can it save money from protecting against unplanned outages, but condition monitoring also improves productivity, quality, and profitability.

GE's Bently Nevada 3500 Monitoring System provides continuous, online monitoring suitable for machinery protection and asset condition monitoring applications. It represents a capable and flexible system in a traditional rack-based design, offering numerous features and advantages not provided in other systems.

Share your equipment monitoring requirements and challenges, large and small, with application specialists. The combination of your process and facilities knowledge, with their product application expertise, will produce effective solutions.

Industrial Machinery and Asset Condition Monitoring from Classic Controls, Inc.

The Focus of 80 GHz Radar Level Instruments Applied to Bulk Solids

VegaPuls 69 - 80 GHz radar level transmitter for bulk solids
Courtesy VEGA

Level measurement of  bulk solids presents a range of challenges to process designers and operators. One instrument manufacturer, VEGA, has produced a video demonstrating a distinct advantage of utilizing 80 GHz radar level transmitters instead of those with lower operating frequencies. The demonstration shows actual instruments in use, along with displays of the actual output from the device. You should find it useful.

VEGA manufactures a wide range of instruments for measuring level, interface, density, and pressure for process control applications. Share your process measurement challenges with product application specialists, and combine your process knowledge with their product expertise to develop effective solutions.

Thermal Flowmeters with Constant Temperature Differential (∆T) Technology to Measure Mass Flow Rate of Air and Gases

Thermal Flow Meter
Sensor
Fox Thermal Instruments

Thermal flow meters use a constant temperature differential (∆T) technology to measure mass flow rate of air and gases. The thermal mass flow sensor consists of two Resistance Temperature Detectors (RTD’s). The sensor elements are constructed of a reference grade platinum wire wound around ceramic mandrels that are inserted into stainless steel or Hastelloy tubes.

The reference RTD measures the gas temperature. The instrument electronics
heat the mass flow sensor, or heated element, to a constant temperature and measures the cooling effect of the gas flow. The electrical power required to maintain a constant temperature differential is directly proportional to the gas mass flow rate. The microprocessor then linearizes this signal to deliver a linear 4 to 20mA signal.

One manufacturer, Fox Thermal Instruments, implements a

technology they call the Power Pro™ Sensor. Their sensor operates at a higher power level than other competitive thermal technologies, providing better response time and wider turndown. When compared to a typical differential pressure type flow meter, as shown to the right, the Power Pro™ Sensor offers better low flow or low end sensitivity. The Power Pro™ Sensor also provides exceptional accuracy at high velocities - up to 50,000 SFPM air.

The Fox DDC-Sensor™ is a new state of the art sensor technology used in the Fox Model FT1 Thermal Gas Flow Meter. The DDC-Sensor™, a direct digitally controlled sensor that is interfaced directly to the FT1 microprocessor for more speed and programmability.

Like the Power Pro™ Sensor, the DDC-Sensor™ accurately responds to changes in process variables (gas flow rate, pressure, and temperature) which are used by the microprocessor to determine mass flow rate, totalized flow, and temperature.

In addition to measuring flow, the DDC-Sensor™ provides a technology platform for calculating accurate gas correlations. The FT1 correlation algorithms allow the meter to be calibrated on a single gas in the factory while providing the user the ability to select other gases in the Gas-SelectX® gas menu. Fox’s Model FT1 with its DDC-Sensor™ and state-of-the-art correlation algorithms provide an accurate, multi-gas capable thermal flow meter for gas applications.

Thermal Mass Flowmeter and Temperature Transmitter from Classic Controls, Inc.

Radar Liquid Level Measurement Through a Sight Glass

Radar level control installed at tank sight glass
Courtesy VEGA

Level measurement, ubiquitous throughout processing operations, can be accomplished through the use of a number of different technologies. VEGA, a globally recognized innovator in level measurement, has authored a white paper outlining how radar level measurement instruments can be successfully employed when installed on tanks with sight glasses. The white paper is excerpted below, and you can access the full article and a wealth of application expertise by reaching out to an application specialist.

The balance of this article is excerpted from "Using radar sensors to measure liquid level through sight glasses", released by VEGA on 10/25/2016.

Vessels with sight glasses permit users to measure liquid level in a unique way: by mounting a radar sensor above the glass. Radar instruments emit microwaves that penetrate the glass, reach the product inside, and reflect through the glass back to the sensor. This eliminates two major expenses because users are spared from retrofitting a tank to accommodate a sensor and can continue running a process during installation. Functionally, nothing changes as users can simply move the sensor for a moment to look through the glass and see what’s happening inside a vessel.

Challenges to radar level measurement through sight glass

Any radar sensor can measure liquid level through a sight glass, but what happens after a signal penetrates glass varies depending on the sensor. Glasses are often welded, bolted or clamped directly onto a vessel wall or roof with a circular flange, while others are mounted on a nozzle. Radar sensors with a transmission frequency of 26 GHz release wide beams that contact the sides of the flange, the nozzle, and sometimes the roof of the vessel itself. This creates noise at the top of the output, especially on taller nozzles, forcing operators to leave empty space inside a tank to make a clear distinction between the signal received from the vessel and the signal received from the product.

Further complicating the use of 26 GHz sensors with sight glasses is the fact that most sight glasses are installed at a natural slope in the tank. Angled glasses narrow the path to the liquid, increasing the degree of difficulty in setting up a sensor so the beam is perpendicular to the product. Perpendicularity is important because it’s in direct relationship to the strength of the signal the sensor receives. However, to minimize the small signals that bounce from the glass to back the sensor, it’s recommended that users pair a 26 GHz radar sensor with a sight glass installed at a 45° angle. This forces users to choose between a strong signal from the product accompanied by reflections from the glass or a weak signal from the product and no reflections for the glass. Neither scenario is ideal.

Enhanced signal focusing makes all the difference

The problem of noise from fittings and narrow paths can be solved by installing a radar sensor that operates at a higher transmission frequency and produces a more focused signal. The VEGAPULS 64, for example, has a frequency of 80 GHz and can emit a beam angle of only 3°. 26 GHz sensors, on the other hand, emit beam angles of approximately 10°. A narrow beam angle misses the sides of the flange and the nozzle, silencing signal noise. That same focused beam can travel a tight path to the product without sacrificing signal strength. Finally, 80 GHz radar sensors don’t need sight glasses at extreme angles to minimize reflected signals, as a sight glass installed at a 5-10° angle will do.

Other benefits of external level instruments

All this is welcome news to processes where sight glasses already exist and is also noteworthy for those struggling with level measurement technology in traditional tanks. Users in the latter camp may find it more economical to install an external radar level sensor and a sight glass than a new internal instrument because removing a sensor from the interior of a vessel presents users with several benefits. In applications involving harsh, caustic liquids, there’s no risk of the product damaging the sensor with a quick splash or corroding it over time through buildup. This saves users in routine maintenance costs, and lack of exposure extends a sensor’s life. Users can mount a radar sensor above such tanks, and the emitted microwaves penetrate the glass and reliably measure the harsh liquid inside.

External access to a level measurement instrument is also useful for a quick repair or recalibration. With the sensor on the outside of the vessel, users can keep the plant’s process moving while they perform routine maintenance. If a problem arises with an instrument inside of a tank, that particular tank—or worse, an entire line—might have to be shut down, potentially leading to thousands of dollars in lost production. What company can afford that?

Summary

In conclusion, radar sensors of any transmission frequency can be mounted above sight glasses for accurate, non-contact level measurement. Separation from the product helps preserve sensors, and the instruments are easy to access when calibration and maintenance are necessary. When researching their options, users should consider 80 GHz sensors because they emit focused radar beams that take a narrow path to the liquid and fewer signals are reflected by flanges and mounting nozzle interiors. Given radar technology’s accuracy and reliability, and all that can go wrong if an internal level measurement fails, a radar sensor mounted above a sight glass offers nothing but advantages.

Going International With Your Design - Solenoid Operated Valves

Industrial Solenoid Valve
Emerson - ASCO

It's no secret to you, Engineer, that the world is densely populated with standards and approvals. No matter where you live or work, the process equipment designs that flow from your workstation, your team, your company, are more likely than ever to end up on foreign shores.

Solenoid operated valves are ubiquitous, even a little mundane in their apparent simplicity, but still require expertise for proper specification and application. The jurisdictional requirements for a valve assembly applied in the same manner can vary from one country to another. This can be especially important when designing equipment or processes that may be installed in different parts of the world, such as United States and European Union production plants of a single company.

Fortunately, many manufacturers now provide valves with multiple approvals from around the world to facilitate the use of a single component across a wide geographic and jurisdictional range. Even with this accommodation, it is still the specifying engineer’s responsibility to select the correct valve, not only for the application, but for a regulatory environment that is populated with standards and approvals that can be difficult to coordinate with confidence. One prominent valve brand, ASCO, provides a white paper that delivers some insight into navigating this challenge, outlining an array of international approval agencies and providing a clear explanation of how T-codes (temperature codes) vary between US and EU agencies. The white paper is included below, a must-read for any engineer specifying or servicing solenoid valves.

Share your process control valve requirements and challenges with product application experts. Their expertise and your process knowledge, when combined, will deliver effective solutions.

Asco solenoid valve temperature code explanation whitepaper from Classic Controls, Inc.

Classic Controls Value Added Services

Valve automation and repair specialists
Classic Controls 

Classic Controls, in addition to being a distributor of industrial process measurement and control gear, also provides a range of value added services to its customers.

The company has the resources to manage and perform a wide range of projects involving process instrumentation, controls, and systems integration. Experienced technicians, engineers, and managers can complete projects of almost any size.

Classic Controls is a selected Yokogawa Vigilant Plant Solutions Partner, a status not easily achieved. This affords the company the training and resources needed to deliver best in class service to customers.

As a GE Masoneilan Authorized Repair Center (MARC), Classic Controls combines quality products with the maintenance of expert level service capabilities for these industrial valves.

Classic Controls provides an extensive valve automation center capability, with experienced technicians and engineers to deliver a complete valve automation package.

Reach out to Classic Controls with your process control challenges and requirements. Combine their experience and expertise with yours to produce successful project completions.

Yokogawa VigilantPlant Solutions Partner from Classic Controls, Inc.

Comparison of Industrial and Commercial UPS

Uninterruptible Power System
Ametek - Solidstate Controls

In our hyper-paced digital age, maintaining a continuous supply of clean electrical power is a key element of facility operation. The microprocessors embedded in most modern devices, coupled with organizational financial pressures to limit losses and downtime, create an environment where an uninterruptible power system is an easily justifiable design inclusion, if not a necessary one.

Commercial installations of UPS may have somewhat differing overall requirements from units placed in industrial service. Ametek Solidstate Controls, a recognized manufacturer of specialized uninterruptible power systems for a broad array of applications, authored a white paper outlining the terms used to describe UPS and the differences between units slated for industrial and commercial applications. The paper delivers some depth and insight on the subject and will likely boost your understanding of the equipment and the concept of an uninterruptible power system.

More information is available from product application specialists, with whom you should share your power system requirements and challenges to develop effective solutions.

Comparison of Commercial vs Industrial UPS from Classic Controls, Inc.

High Performance Butterfly Valves Meet Special Application Challenges

High Performance
Butterfly Valve
ABZ Valve

Industrial process control applications can present stringent and challenging performance requirements for the physical equipment and components that comprise the process chain. The valves employed in fluid based operations need to be resistant to the impact of extreme fluid conditions, requiring careful design and selection consideration to assure proper performance and safety levels are maintained in a predictable way.

Industrial valves intended for extreme applications are generally referred to as severe service or high performance valves. While there are plenty of published and accepted standards for industrial valves, one does not exist to precisely define what constitutes a severe service valve.

So, how do you know when to focus valve selection activities on severe service or high performance valves, as opposed to those rated for general purpose? There are a number of basic criteria that might point you in that direction:

• Extreme media or environmental temperature or pressure
• High pressure drop operation that may cause cavitation
• Rapid or extreme changes to inlet pressure
• Certain types or amounts of solids contained in the fluid
• Corrosive media

Certainly, any of these criteria might be found in an application serviceable by a general purpose valve, but their presence should be an indicator that a closer assessment of the fluid conditions and commensurate valve requirements is in order. The key element for a process stakeholder is to recognize when conditions are contemplated that can exceed the capabilities of a general purpose valve, leading to premature failure in control performance or catastrophic failure that produces an unsafe condition. Once the possibility of an extreme or challenging condition is identified, a careful analysis of the range of operating conditions will reveal the valve performance requirements.

There are numerous manufacturers of severe service or high performance valves, each with specialized product offerings focusing on a particular performance niche. ABZ Valve manufactures high performance butterfly valves ranging from 2-48 inches and 150-600 psi. The valve design is ideal for manual or automated actuation, installed with a manual hand gear, electric actuator, or a pneumatic actuator. Seats are available as soft, metal, and fire safe, and body types include wafer, double flanged, and butt-welded. Construction materials include carbon steel and 316 stainless steel. A range of options and variants are available to customize the valve build to suit a replacement or new installation.

More information about the ABZ  Valve high performance offering is included below. You can always get more information and discuss your special requirements with a valve specialist. They have application experience and access to technical resources that can help with selecting the right valve components to meet your severe service and high performance applications.

Double Offset High Performance Butterfly Valves from Classic Controls, Inc.

Magnetic Liquid Level Gauges in Industrial Settings

Magnetic liquid level gauge combined with
guided wave radar in a single assembly
Vega Americas

Magnetic liquid level gauges are an excellent alternative to sight glass level gauges for many process measurement applications. Their reliable performance and adaptability to process requirements has made them a primary choice in the industrial arena.

Essentially, a magnetic level gauge or magnetic level indicator, is a sight glass with enhancements that provide better readability and a form factor enabling the inclusion of additional level monitoring functions on the same device. Where a sight glass requires operator proximity to read liquid level, the magnetic level gauge's indicating scale, or flags, can be clearly viewed from a considerable distance. A sight glass gauge can also be hindered by difficulties in visually determining liquid level because of deterioration of the glass surface or physical properties of the liquid. Magnetic level gauges remove the need to observe the liquid directly by incorporating a float device within a tube connected to the liquid containing vessel. As the float moves in response to liquid level changes, its magnet causes the indicator flags on the scale to rotate and display either a black face, indicating no liquid present at that position, or a colored face.

Magnetic level indicators or gauges can be modified with a range of options, including armored casings to protect the tube and float arrangement and limit switches to signal attainment of predetermined liquid levels. Combining a magnetic level indicator with another level measurement technology, such as guided wave radar or magnetostrictive, in a single assembly can provide an analog process signal representing continuous liquid level and serve as a redundant measuring device for critical applications.

The document included below provides illustrated detail about the devices and their proper application. There is more detail available, so share your process measurement requirements and challenges with instrumentation experts. The combination of your process knowledge and their product application expertise will produce effective solutions.

Combination magnetic and guided wave radar liquid level indicator from Classic Controls, Inc.

Accurate Measurement of Low Flow In Compressed Air Systems

Air compressors can incur significant operating costs.
Minimizing system leaks reaps savings.

Plant operators are well aware of the cost associated with continuous delivery of  compressed air, a useful medium utilized as an energy source. Large or multiple compressors consume considerable amounts of electric power maintaining system pressure and flow requirements. With extensive piping and countless fittings, there are many potential points of leakage. Scheduling of various production operations can vary the demand for compressed air significantly. Getting control of your compressed air system and reducing operating cost is a noble goal. One of the primary tools needed to manage energy costs will be accurate and reliable flow measurement equipment. Here are some characteristics of flow measurement instrumentation that should prove advantageous:

Portable Ultrasonic Flow Measurement Instrument
Flexim

• Non-invasive measurement from the outer pipe wall that does not add potential leak sources or pressure drop.
• Availability in fixed or portable configuration.
• Highly accurate, with paired temperature compensated traceable calibrated transducers
• Installed without disturbance to piping.
• Bidirectional measurement
• Rugged instrument design suitable for any kind of industrial environment

Ultrasonic flow measurement technology can provide all of these characteristics, providing
information that enables the operator to make fact based decisions about system design, management, and maintenance. Learn more about how ultrasonic flow meters specifically configured for compressed air system application can help you start reducing your operating cost and developing a higher level of control over your compressed air system. Share your process challenges with a product specialist and work together to build the best solution.

Portable flow meter for measurement of compressed air, gases, and heat quantitites from Classic Controls, Inc.

New Website For Classic Controls

Home page on Classic Controls new website

Classic Controls, distributor of industrial process measurement and control equipment and instruments throughout Florida, Georgia, Puerto Rico, and the Caribbean, has a new website that is live now. The new site provides simple and rapid access to Classic Controls' represented lines and products, as well as the company's social media outlets, all organized in an intuitive and useful fashion to save users time in their search for solutions.

Visit the new site and see the products and capabilities of Classic Controls.

Dust Measuring Instrument Combines Two Measuring Technologies

Model C200 combines transmittance and forward scattering
light methods to produce wide range dust measurements
Sick, Inc.

In the power industry, as well as others, dust and particle detection and measurement in emissions is an important element of compliance with environmental protection regulations. Stacks, ducts, and other conduits of gas or air transmission can be accurately monitored using instrumentation which incorporates the use of controlled light sources, sensitive detectors, and advanced processing software.

Two light based dust measurement methods of note are transmittance and forward scattering. Sick USA (pronounced like "seek"), in their extensive line of dust measurement instrumentation, offers a unit incorporating both of these technologies to provide accurate measurement across a wide range of conditions not attainable with units employing either of the technologies singly. The system consists of two compact enclosed units which are mounted on opposing sides of a duct or pipe. These house the light sources and detectors. There is also an enclosed control unit which is remotely mounted. A range of configuration options are available to meet specific application requirements and interface with a centralized control or monitoring system.

• Transmittance and scattered light measurement combined in a single instrument
• Suitable for dust concentrations from very low to high
• Self check of zero and reference point are automatic
• Contamination monitoring and compensation on both sides
• Automatic self-alignment
• Designed for medium to large duct diameters
• Suitable for sharply fluctuating dust concentrations
• Reliability achieved through redundant measurement
• Self-monitoring activity keeps maintenance requirements low
• Equipped for limit values that will become smaller in the future

The data sheet included below provides additional detail. More information about the complete line of dust measurement instrumentation is available. Share your emission monitoring requirements and challenges with application experts. The combination of your process knowledge and their product application expertise will bring effective solutions.

Dual technology dust measurement instrument from Classic Controls, Inc.

Process Gas Chromatograph - Practical Implementation of Parallel Chromatography

Process Gas Chromatograph
Yokogawa GC8000

Gas chromatography is a common analysis tool employed in many areas of the process control industry, including oil and gas, pharmaceutical, chemical, and others. Yokogawa Corporation of America developed instrumentation to provide top tier GC performance with their GC8000 Process Gas Chromatograph for use in oil and gas, and other industrial applications.

In addition to the ruggedness and reliability for which Yokogawa gas chromatographs are well known, the GC8000 brings a number of innovations and improvements to the company’s process gas chromatography product offering.

> Color touchscreen HMI for easy operation

> Advanced predictive diagnostics and software functions monitor key performance indicators during each analysis to verify analyzer is operating within proper tolerances.

> Parallel chromatography is made practical through the use of the GC Modules provided as part of the GC8000. Virtual GCs can be set up inside a single GC with GC Modules to measure multiple streams simultaneously.

The graphics below expand on this overview of the GC8000 Process Gas Chromatograph, the culmination of Yokogawa’s 55 years of experience in the field. For more detailed information, or to discuss your application specifics, contact a product specialist.

Process Gas Chromatograph for Industrial Use from Classic Controls, Inc.

Electric Actuators for Industrial Valve Automation

Multi-turn Electric Actuator
AUMA

Electric actuators bring automation to industrial valve operation, allowing complex processes to be managed and controlled by remotely located control systems. There are other motive forces used for valve actuators, including hydraulic and pneumatic, but electric actuators carry their own particular set of operating characteristics that make them an advantageous choice for many applications.

Valve actuators are available in uncountable variants to suit every application scenario. There are three basic valve actuation motions.

• Multi-turn, with repeated rotations of the valve shaft needed to move the valve trim from fully open to fully closed. A gate valve is a multi-turn valve. These are also called linear, with respect to the motion of the closure element. The term "linear", in this case, refers only to the movement of the valve trim and not the flow characteristics of the valve.
• Part Turn, where a 90 degree rotation of the valve shaft produces a change from opened to closed. Ball valves are in this category.
• Lever, generally associated with damper control.

An electric actuator is a combination of motor and gearbox with sufficient torque to change valve trim position. A local self-contained control commands the motor and provides feedback to the process master controller regarding position, travel, torque, and diagnostics. Several interface options are available to facilitate communication between actuator and master controller.

There are numerous considerations to take into account when selecting an electric actuator.

• Torque needed to effectively operate the subject valve.
• Actuator enclosure type - wash down, hazardous area, dust, etc.
• Service area for the assembly - corrosive environment, temperature extremes, and more
• Valve movement - linear, multi-turn, part turn, lever
• Operation mode - open and close only, positioning, modulating
• Frequency or duty cycle - infrequent, frequent, or almost continuous positioning
• Communication - How will the local controller communicate with the central control system?
• Electrical - What electric power characteristics are available for operation?
• Protections - Motor overload, torque limit, others
• Process Safety - Among other things, what happens if power fails? 

There are certainly other elements to consider when applying an electric actuator for industrial use. You can see more detail about electric actuator operation and available configurations in the document included below. It is well illustrated and clearly describes the various aspects mentioned in this article. Share your valve and actuator requirements and challenges with product specialists, combining your process knowledge with their product application expertise to forge the most effective solutions.

Electric Actuators for Industrial Valve Automation from Classic Controls, Inc.

Hydrostatic Level Measurement

Submersible Pressure Transmitter
VEGA

Liquid level can be inferred by accurately measuring the pressure produced by the height of a fluid column and knowing the density of the liquid measured. The measurement is comparative in nature, referencing some external pressure as a zero point. The zero point can be the surrounding atmospheric pressure, tank pressure, or the pressure exerted by another column of liquid contained elsewhere.

There are uncountable application scenarios, each with its own set of special conditions. Proper instrument selection, installation and calibration are essential to generating reliable and accurate results.

The VEGA hydrostatic pressure transmitters are specially designed to provide level measurements across a wide range of liquids with different properties. Some units provide media temperature measurement as well. The product centers around three basic units, with numerous variants and options that can be used to configure an instrument for any application.

Browse the document included below to see application examples, setup instructions, and the extensive array of configurations available with these pressure transmitters from VEGA. Contact product specialists to share your application challenges and get effective solutions.

Submersible Pressure Transmitter for Level Measurement from Classic Controls, Inc.

Steam Desuperheaters

Diagram of one type of steam desuperheater
Schutte & Koerting

Steam has been a preferred means of delivering energy for many decades. Whether used for propulsion, as when driving a turbine, or delivery of heat, steam has proven to be an acceptably reliable and safe means of energy transfer.

Steam can exist in a saturated or superheated state. When saturated, molecules are at the minimum energy level needed to maintain a gaseous state. Superheated steam is essentially steam that has additional sensible heat content beyond what is necessary to create saturated steam. Some processes, such as turbines, will operate best with superheated steam. Heat transfer processes will often provide their best efficiency with saturated steam. Whatever the case, there can be instances where it is preferential, or necessary, to reduce the superheat level of process steam.

Desuperheaters reduce the sensible heat content of steam through a number of methods, most that involve adding finely atomized water to the steam flow. The document included below outlines various construction methods and principles of operation for steam desuperheaters. The illustrations, diagrams, and explanatory content will provide a useful overview of this common industrial process, including application examples.

Types of Steam Desuperheaters from Classic Controls, Inc.

When to Use a Globe Valve for Fluid Process Control

Heavy duty industrial globe valve with pneumatic actuator
Masoneilan brand of GE

Industrial process control often involves the regulation of fluid flow. There are almost uncountable types and variants of flow control valves, each with a particular set of attributes that can make it the advantageous choice to meet certain applications.

When the process calls for controlling flow over a range of possible values, known as throttling, a globe valve may be a good candidate for the application.

Globe valves are characterized by the change in direction of fluid flow as it passes through the valve and the plug or disk positioned in an opening through which fluid must pass. The plug is connected to a stem extending to the exterior of the valve body through the bonnet. Movement of the stem will reposition the plug in relation to the opening, providing a successively larger or smaller opening area through which fluid can pass.

Simple globe valve diagram
Courtesy Wikipedia

Globe valves are available in tee, angle, and wye configurations, as well as an enormous range of special configurations to suit specific applications.

What are some potential advantages of globe valves?

• Good throttling and shutoff capability
• Comparatively easy maintenance
• Comparatively short travel of plug from open to closed position
• Seats can usually be resurfaced when worn

What are some limiting factors for globe valves?

• Higher valve pressure drop than some other designs
• No straight through fluid path
• Comparatively higher actuator torque requirements to operate valve

When flow throttling capability is the overriding concern for an application, a globe valve could be a good candidate for consideration. Share your flow control challenges with product specialists. Combining your process knowledge with their product application expertise will produce effective solutions.

Fuel Air Ratio Controller for Combustion Efficiency

Combustion efficiency reaps substantial cost savings

Steam and hot water use is prevalent throughout industrial processes. Production of these two media is most commonly accomplished with a boiler, many of which are heated by combustion of fossil fuel. Fuel fired boilers of a certain size become the focus of regulatory requirements for emissions. All boilers consume what would be construed by their owners as large amounts of costly fuel. Because of their high pressure and temperature, and the presence of a controlled combustion within an occupied facility, safety is a paramount concern.

There, fortunately, is a single solution that can help to attain useful goals with the three concerns of safety, fuel cost, and regulatory compliance. Applying an efficiency controller to manage the fuel to air ratio of the combustion system will deliver benefits far in excess of the cost to incorporate the necessary devices. The three basic goals for the fuel air controller are:

• Maximize fuel efficiency
• Minimize regulated emissions
• Maintain safe operating condition

A good portion of all three goals can be accomplished through careful concerted control of combustion air supply and fuel supply. The fuel air ratio must be subject to continual adjustment in response to current air conditions (which can vary on a daily basis) and the level of O2 in the flue gas. Controlling the air fuel ratio supports the following goals:

• Preventing excess fuel vapors from entering the flue and creating an unsafe condition
• Providing the correct amount of air to effectively combust the fuel supplied to the burner
• Preventing excess air flow from reducing net heat transfer to the feedwater
• Maintaining regulated emissions within required limits
• Limiting fuel consumption to the minimum necessary to meet demand

Fireye® is a leading manufacturer of flame safeguard controls and burner management systems for commercial and industrial applications throughout the world. Their products, the first of which was developed in the 1930's, enhance the safety and efficiency of all fuel fired burners.

There are numerous capabilities built in to the company's PPC4000 series of fuel air ratio controllers. Some of the more notable include:

• Precise fuel air ratio attained using parallel control of servos to regulate fuel and air supplies.
• User selected burner profiles
• Alarm contacts
• PID operation
• An array of inputs and outputs to accommodate sensors and devices needed to monitor and control boiler operation
• Compatible with other products that provide additional flame and burner monitoring safety
• Multiple boiler sequencing and cold start thermal shock protection
• On board boiler efficiency calculation
• User interface, optional larger touchscreen interface

Glance through just the first two pages of the document below to get a full description of the capability of this compact and comprehensive controller. You can get more detailed information, or get a professional evaluation of your current system efficiency, by contacting the combustion experts at Classic Controls.

Fuel Air Ratio Controller for Combustion Equipment from Classic Controls, Inc.

Solenoid Valve Operating Principle

One of many solenoid valve variants
Courtesy Burkert

A solenoid is an electric output device that converts electrical energy input to a linear mechanical force.

At the basic level, a solenoid is an electromagnetic coil and a metallic rod or arm. Electrical current flow though the coil produces a magnetic field, the force of which will move the rod. The movable component is usually a part of the operating mechanism of another device. This allows an electrical switch (controller) to regulate mechanical movement in the other device and cause a change in its operation. A common solenoid application is the operation of valves.

A plunger solenoid contains a movable ferrous rod, sometimes called a core, enclosed in a tube sealed to the valve body and extending through the center of the electromagnetic coil. When the solenoid is energized, the core will move to its equilibrium position in the magnetic field. The core is also a functional part of valve operation, with its repositioning causing a designed changed in the valve operating status (open or close). There are countless variants of solenoid operated valves exhibiting particular operating attributes designed for specific types of applications. In essence, though, they all rely on the electromechanical operating principle outlined here.

A solenoid valve is a combination of two functional units.

• The solenoid (electromagnet) described above.
• The valve body containing one or more openings, called ports, for inlet and outlet, and the valve interior operating components.

Flow through an orifice is controlled by the movement of the rod or core. The core is enclosed in a tube sealed to the valve body, providing a leak tight assembly. A controller energizing or de-energizing the coil will cause the valve to change operating state between open and closed, regulating fluid flow.

Share your control valve requirements and challenges with a valve application specialist. Combining your process application knowledge with their product expertise will produce the most effective solutions.

Comparison of Three Lightning Protection Approaches

Lightning strikes pose a substantial hazard
to the operation of electrical equipment

Protection from lightning strikes is an essential part of securing the safe and continuous operation of any commercial or industrial process or facility. Systems and equipment selected, purchased, and installed to protect against lighting strikes will likely be in place for a long time, so it is important to make a sound decision at the outset.

Dehn Inc. has been providing lightning protection and related equipment since 1910. They have provided a white paper comparing blunt rod lightning protection to other methods, including early streamer emission (ESE) and lightning dissipation array (LDA). The paper also provides some historical background of efforts at lightning protection and avoids overly technical jargon.

Browse the white paper. It is not lengthy and provides useful insight into the lightning protection field. Share your lighting protection requirements and challenges with application specialists and work together to formulate effective solutions.

Blunt rod lightning protection advantages over nonconventional approaches from Classic Controls, Inc.

Data Acquisition - Precursor of Control and Decision Making

Models DX1000 and DX2000 Data Acquisition Units
Courtesy Yokogawa Corp.

Data acquisition, like an equipment acquisition, is the procurement of an asset. Data is an asset. It helps an operator evaluate process or business conditions and make decisions that impact the success of the organization. Let’s define data acquisition as the sampling of signals that represent a measurement of physical conditions and the conversion of those signals into a numeric form that can be processed by a computer. A data acquisition system will generally consist of sensors, transmitters, converters, processors, and other devices which perform specialized functions in gathering measurements and transforming them into a usable form.

Industrial process operators and stakeholders benefit from the collection and analysis of data by enhancing performance of valuable facets of the process or activity. Data acquisition, commonly known as DAQ, is widely employed throughout industry where there is a true need to know current conditions and analyze trends, patterns, or events. A desire for increased profit drives the need for increased process output and efficiency. A desire to reduce risk of loss drives the need for reduced downtime and improved safety. Today, there are likely many useful applications for data acquisition that are not being tapped to their fullest potential. The modest cost and simplicity of putting a data acquisition system in place, compared to the benefits that can be derived from a useful analysis of the data for your operation or process, makes the installation of a data acquisition system a positive move for even small and unsophisticated operators in today’s market.

Other examples of industrial data acquisition equipment

Courtesy Yokogawa Corp.

What we call DAQ today started in the 1960’s when computers became available to businesses of large scale and deep pockets. By the 1980’s, personal computers employed in the business environment could be outfitted with input cards that enabled the PC to read sensor data. Today, there is an immense array of measurement and data collection devices available, spanning the extremes of price points and technical capability. For a reasonable cost, you can measure and collect performance data on just about anything. You can get an impression of the simplicity, modularity, and compactness of a modern system with a quick review of this product from Yokogawa, a globally recognized leader in the industrial data acquisition equipment field.

Data acquisition has an application anywhere an operator or stakeholder can benefit from knowing what is occurring within the bounds of their process or operation. Here is a partial list of the many physical conditions that can be measured in industrial settings.

• Temperature
• Pressure
• Level
• Flow
• Force
• Switch Open or Closed
• Rotational or Linear Position
• Light Intensity
• Voltage
• Current
• Images
• Rotational Speed

Consider your industrial process or operation. Are there things you would like to know about it that you do not? Would you like to increase your insight into the workings of the process, how changes in one condition may impact another? Do you know what operating condition of each component of your process will produce the best outcomes? Is reducing maintenance, or heading off a failure condition before it occurs something you would like to have in your operation? Applying your creativity, ingenuity and technical knowledge, along with the help of a product expert, will help you get the information you need to improve the outcomes from your industrial process or operation.

Yokogawa Data Acquisition Station DX1000 & DX2000 from Classic Controls, Inc.

A Step Forward in Non-contact Radar Liquid Level Measurement

VEGAPULS 64 80 GHz Radar Liquid Level Sensor

Employing non-contact level measurement in a process control operation has many potential benefits. Radar level measurement has gained acceptance as an accurate and reliable method of liquid level measurement. The process measurement instrumentation manufacturers have continually made strides in the evolution of their product offerings, providing more effective lower cost solutions.

VEGA, a global leader in the manufacture of level and pressure instrumentation for the process industry, has introduced a new radar liquid level sensor. The VEGAPULS 64 operates at 80 GHz, a substantially higher frequency than previous models. The higher radar frequency, along with some other improvements, deliver operational benefits.

Tight beam focus accommodates
vessel internal fixtures
Courtesy VEGA

• Measurement is unaffected by condensation or buildup on the antenna
• High measurement certainty with product deposits on vessel walls
• System is quickly available for operation after cleaning cycles
• Tight focusing of the radar beam on the liquid surface provides easier setup and commissioning with complex vessel internal fixtures.

The radar level sensor is available with a number of connection fitting sizes, extending down to 3/4", which enable retrofitting of this improved technology to smaller vessels without extensive modification. There is also an encapsulated antenna variant that is suitable for hygienic or chemical applications.

There is more to learn about the advances in radar level sensors. Reach out to product specialists for more information. Share your level measurement challenges with the product specialists, then combine your process expertise with their product knowledge to produce effective solutions.

VEGAPULS 64 Encapsulated Version