Thank You Sponsors!

AVENSYS.COM

CANCOPPAS.COM

DAVISCONTROLS.COM

ENDRESS.COM

EVERESTAUTOMATION.COM

FRANKLINEMPIRE.COM

HCS77.COM

MAC-WELD.COM

PEP-PETRO.COM

SPSSALES.COM

SRPCONTROL.COM

SUMMIT-INSTRUMENT.COM

WESTECH-IND.COM

VERONICS.COM

WAJAX.COM

WIKA.CA

Webinar Recording: Advanced Calibration Techniques Based on Loop Testing

The post Webinar Recording: Advanced Calibration Techniques Based on Loop Testing first appeared on the ISA Interchange blog site.

This ISA webinar on advanced calibration techniques was presented Ned Espy and Roy Tomalino of Beamex.

.videopopup.video__button:before {
border-left: 10px solid #ffffff !important;
}
a.popup-youtube:hover .videopopup.video__button {background: #8300e9 !important;}

While not a new concept, there are advanced calibration techniques based on loop testing. In some cases, it is best practice to perform individual instrument calibration to achieve maximum accuracy (e.g. custody transfer metering). However, there are viable methods where a loop can be tested end-to-end and if readings are within acceptable tolerances, there is no need to break into the loop for individual instrument testing.

Watch this webinar to learn how a common sense approach can minimize downtime and maximize technician efficiency while ensuring reliable control and maintaining a safe work environment.

About the Presenter
Ned Espy has been promoting calibration management with Beamex for more than 20 years. He has directed field experience in instrumentation measurement application for over 27 years. Today, Ned provides technical & application support to Beamex clients and partners throughout North America.

Connect with Ned
LinkedIn

About the Presenter
Roy Tomalino has been teaching calibration management for 14 years. Throughout his career, he has taught on four different continents to people from over 40 countries. His previous roles include technical marketing engineer and worldwide trainer for Hewlett-Packard and application engineer with Honeywell. Today, Roy is responsible for all Beamex training activities in North America.

Connect with Roy:
48x48-linkedinEmail

 



Source: ISA News

AutoQuiz: How Are the Maintainability and Maintenance of Automation Systems Related?

The post AutoQuiz: How Are the Maintainability and Maintenance of Automation Systems Related? first appeared on the ISA Interchange blog site.

AutoQuiz is edited by Joel Don, ISA’s social media community manager.

This automation industry quiz question comes from the ISA Certified Automation Professional (CAP) certification program. ISA CAP certification provides a non-biased, third-party, objective assessment and confirmation of an automation professional’s skills. The CAP exam is focused on direction, definition, design, development/application, deployment, documentation, and support of systems, software, and equipment used in control systems, manufacturing information systems, systems integration, and operational consulting. Click this link for more information about the CAP program.

How are the maintainability and maintenance of automation systems related?

a) maintainability is a front-end, design outcome; maintenance is related to ongoing system availability
b) maintainability is related to system availability; maintenance is related to traceability and warranties
c) maintainability is a front-end engineering function; maintenance is an ongoing engineering function
d) maintainability is related to malfunctions; maintenance is related to service quality
e) none of the above

Click Here to Reveal the Answer

Maintainability is the probability that a device will be restored to an operating condition within a specified period when maintenance is done with prescribed resources and procedures. It can also refer to the inherent characteristic of a design or installation that determines the ease, economy, safety, and accuracy with which maintenance actions can be performed on it.

As such, maintainability should be addressed during the front-end engineering and design phase of a project, so these characteristics are built in to the process. This includes addressing items like accessibility for removing pumps, piping, and instruments; complete documentation and procedures; availability of spare parts; personnel training and qualification; and suitability for purpose.

Maintenance is what is performed on a system to ensure that it remains in good working condition, but also, if a failure should occur, maintenance is the mechanism used to return the system to the previous working condition.

The correct answer is A, “Maintainability is a front-end, design outcome; maintenance is related to ongoing system availability.”

Reference: Nicholas Sands, P.E., CAP and Ian Verhappen, P.Eng., CAP., A Guide to the Automation Body of Knowledge. To read a brief Q&A with the authors, plus download a free 116-page excerpt from the book, click this link.

About the Editor
Joel Don is the community manager for ISA and is an independent content marketing, social media and public relations consultant. Prior to his work in marketing and PR, Joel served as an editor for regional newspapers and national magazines throughout the U.S. He earned a master’s degree from the Medill School at Northwestern University with a focus on science, engineering and biomedical marketing communications, and a bachelor of science degree from UC San Diego.

Connect with Joel
LinkedInTwitterEmail

 



Source: ISA News

How to Manage Control Valve Response Issues in the Field

The post How to Manage Control Valve Response Issues in the Field first appeared on the ISA Interchange blog site.

The following technical discussion is part of an occasional series showcasing the ISA Mentor Program, authored by Greg McMillan, industry consultant, author of numerous process control books, 2010 ISA Life Achievement Award recipient and retired Senior Fellow from Solutia Inc. (now Eastman Chemical). Greg will be posting questions and responses from the ISA Mentor Program, with contributions from program participants.

In the ISA Mentor Program, I am providing guidance for extremely talented individuals from countries such as Argentina, Brazil, Malaysia, Mexico, Saudi Arabia, and the USA. This question comes from Mohd Zhafran A. Hamid.

Mohd Zhafran A. Hamid is a senior instrument engineer from Malaysia working in an EPC company, Toyo Engineering Corporation. He has worked in the field of control and instrumentation for about 10 years mostly in both engineering design and involvement at site/field.

Mohd Zhafran’s First Question

If you have selected a control valve whose installed flow characteristics significantly deviates from linear (either by mistake or forced to select due to certain circumstances), what is a practical way in the field after installation to linearize the installed flow characteristic?

Greg McMillan’s Answer

You need a sensitive flow measurement to identify the installed flow characteristic online. If you have a flow measurement and make changes in the manual controller output five times larger than dead band or resolution limit spaced out by a time interval greater than the response time, the slope of the installed flow characteristic is the change in per cent flow divided by the change in per cent signal. You need at least 20 points identified on the installed flow characteristic.

A signal characterizer is then inserted on the controller output to convert the flow in percent of scale to percent signal to get a piecewise linear fit that would linearize the characteristic so far as the controller is concerned. The controller output and linearized signal to the valve should be displayed. This linearization can be done in a positioner, but I prefer it being done in the DCS or PLC for better visibility and maintainability. For much more on signal characterizers see my Control Talk blog Unexpected benefits of signal characterizers.

ISA Mentor Program Posts & Webinars

Did you find this information of value? Want more? Click this link to view other ISA Mentor Program blog posts, technical discussions and educational webinars.

Mohd Zhafran’s Second Question

I recently read the addendum “Valve Response Truth or Consequences” in Greg’s article How to specify valves and positioners that do not compromise control. I am curious for fast loop whereby the control valve is used with volume booster but without positioner, how come you can move the stem/shaft by hand only even though the valve size is big. Would you mind sharing the overall schematic? Also, would you also share the schematic of using positioner with booster and booster bypass?

Greg McMillan’s Answer

Positive feedback from a very sensitive booster outlet port is greatly assisting attempts to move the shaft either manually or due to fluid forces on a butterfly disk as described in item five of my Control Talk blog Missed opportunities in process control – Part 6. There is a schematic of the proper installation in slide 18 of the ISA Mentor Program webinar How to Get the Most out of Control Valves. I don’t have a schematic of the wrong thing to do where the volume booster input is connected to current to pneumatic transducer (I/P) output.

For new high pressure diaphragm actuators or boosters with lower outlet port sensitivity, this may not happen since diaphragm flexure and consequential change in pressure from change in actuator volume may be less than booster outlet port sensitivity but it is not worth the risk in my book. The rule positioners should not be used on fast loops is mostly bogus as explained in my point 4 in the same Control Talk blog.  If you need a response time faster than 0.5 seconds, you should use a variable frequency drive with a pulse width modulated inverter.

Mohd Zhafran’s Third Question

Greg highlighted the importance to specify valve gain requirement. Is there any publicly available modeling software that we design engineer can utilize to perform valve gain analysis? So far, I have encountered only one valve manufacturer that provides control valve sizing software (publicly available) with feature of valve gain graph. This manufacturer calculates process model based on the principle that the pressure losses in a piping system are approximately equal to flow squared.

Greg McMillan’s Answer

The Control Talk column Why and how to establish installed flow characteristic describes how one practitioner uses Excel to compute the installed flow characteristic. The analysis of all the friction losses in a piping system can be quite complicated because of the effect of process fluid properties and fouling determined by process conditions and operating history and the piping system including fittings, elbows, inline equipment (e.g., heat exchangers and filters), and valves.

A dynamic model in a Digital Twin that includes system pressure drops and the effect of fouling and the ability to enter the inherent flow characteristic perhaps by a piecewise linear fit can show how the valve gain changes for more complex and realistic scenarios. Ideally, there would be flow and pressure measurements to show key pressure drops particularly where fouling is a concern so that resistance coefficients can be back calculated. 

The fouling of heat transfer surfaces can be detected by an increase in the difference needed between the process and utility temperature to compensate for the decrease in heat transfer coefficient. A slow ramp of the valve signal followed by a slow ramp in a flow measurement could reveal the installed flow characteristic by a plot of flow ramp versus the signal ramp assuming there are no pressure disturbances and flow measurement has sufficient signal to noise ratio and rangeability.

For Additional Reference:

Baumann, Hans D., Fluid Mechanics of Control Valves.
McMillan, Gregory K., and Vegas, Hunter, 101 Tips for a Successful Automation Career.

Additional Mentor Program Resources

See the ISA book 101 Tips for a Successful Automation Career that grew out of this Mentor Program to gain concise and practical advice. See the InTech magazine feature article Enabling new automation engineers for candid comments from some of the original program participants. See the Control Talk column How to effectively get engineering knowledge with the ISA Mentor Program protégée Keneisha Williams on the challenges faced by young engineers today, and the column How to succeed at career and project migration with protégé Bill Thomas on how to make the most out of yourself and your project. Providing discussion and answers besides Greg McMillan and co-founder of the program Hunter Vegas (project engineering manager at Wunderlich-Malec) are resources Mark Darby (principal consultant at CMiD Solutions), Brian Hrankowsky (consultant engineer at a major pharmaceutical company), Michel Ruel (executive director, engineering practice at BBA Inc.), Leah Ruder (director of global project engineering at the Midwest Engineering Center of Emerson Automation Solutions), Nick Sands (ISA Fellow and Manufacturing Technology Fellow at DuPont), Bart Propst (process control leader for the Ascend Performance Materials Chocolate Bayou plant), Angela Valdes (automation manager of the Toronto office for SNC-Lavalin), and Daniel Warren (senior instrumentation/electrical specialist at D.M.W. Instrumentation Consulting Services, Ltd.).

About the Author
Gregory K. McMillan, CAP, is a retired Senior Fellow from Solutia/Monsanto where he worked in engineering technology on process control improvement. Greg was also an affiliate professor for Washington University in Saint Louis. Greg is an ISA Fellow and received the ISA Kermit Fischer Environmental Award for pH control in 1991, the Control magazine Engineer of the Year award for the process industry in 1994, was inducted into the Control magazine Process Automation Hall of Fame in 2001, was honored by InTech magazine in 2003 as one of the most influential innovators in automation, and received the ISA Life Achievement Award in 2010. Greg is the author of numerous books on process control, including Advances in Reactor Measurement and Control and Essentials of Modern Measurements and Final Elements in the Process Industry. Greg has been the monthly “Control Talk” columnist for Control magazine since 2002. Presently, Greg is a part time modeling and control consultant in Technology for Process Simulation for Emerson Automation Solutions specializing in the use of the virtual plant for exploring new opportunities. He spends most of his time writing, teaching and leading the ISA Mentor Program he founded in 2011.

Connect with Greg
LinkedIn



Source: ISA News

How to Prevent Impulse Line Blockages Due to Temperature Variability

The post How to Prevent Impulse Line Blockages Due to Temperature Variability first appeared on the ISA Interchange blog site.

This post was authored by Asad Shaikh, an instrumentation and control engineer with Worley.

In the glass manufacturing industry, raw materials are heated to high temperatures until they turn into liquid. At this stage the molten glass is still very viscous, but can be poured into molds to create desired intermediary or final products. Eventually when it cools the molten glass reaches infinite viscosity and solidifies into the desired shape. Thus, temperature and viscosity in a liquid are inversely proportional.

A similar concept applies to industrial impulse lines used to measure differential pressure. The liquid in the main line might have a particular temperature and viscosity, and you might assume that the impulse line won’t clog as it isn’t getting blocked in the main line.

But this is not the case when we puncture this line to enable impulse lines to connect to measuring instruments.

When such fluid flows through impulse lines connected to a pressure measurement device, the operating temperature of fluid drops drastically.

Here’s the reason for the drop in temperature. Impulse lines are typically very small (approximately one-half inch). So for a liquid in such small outside diameter line, most of its surface is in contact with the wall of the pipe and there is a higher transfer of heat, which causes a significant drop in temperature.

Second, the impulse lines are dead legs, and this creates further temperature reduction as the same fluid in the impulse tube is radiating heat.

So depending upon the length of the impulse line we can infer that impulse lines lead to significant drops in fluid temperature compared to the main pipeline.

In a refinery application at one of my project sites, a pipeline had a particular liquid flowing through it. From this line a tapping (sensing line) had to be connected to a pilot relief valve.

The temperature of the pipeline was approximately 300°C but the pilot relief valve was not rated for such high temperatures. (The maximum operating temperature of a pilot valve body varies from vendor to vendor.)

I proposed using a cooling element between the tapping and pilot valve.

Refer the diagram below, which depicts an air-cooled heat exchanger configuration with pilot operated relief valve.

Air-cooled heat exchanger with pilot operated relief valve.

 

The cooling element in the diagram is a miniature air-cooled heat exchanger. It was designed to lower the temperature close to ambient and protect the pilot relief valve. The cooling element would gradually reduce the fluid temperature to ambient conditions. This would lead to an increase in viscosity. After close examination it was determined that when the liquid temperature dropped below 40°C, it would become highly viscous and potentially block the impulse lines.

The pilot relief valve would not act due to the plugged impulse line and the valve – being the last line of defense – would not operate as required, possibly causing a catastrophic event. There have been several industrial accidents caused by such relief valve failures.

The solution was to heat trace the lines to 40°C to mitigate the liquid turning viscous and blocking the lines. So the key takeaway is to closely monitor the temperature of liquids in impulse lines, and always check the viscosity to ensure it is within acceptable operating limits.

About the Author
Asad Shaikh is an instrumentation and control engineer for Worley, designs plants for the chemical and energy sectors. He previously was with Jacobs ECR division, which was acquired by Worley in 2019.

Connect with Asad
LinkedIn



Source: ISA News

AutoQuiz: How to Use the Parity System to Detect Data Transmission Errors

The post AutoQuiz: How to Use the Parity System to Detect Data Transmission Errors first appeared on the ISA Interchange blog site.

AutoQuiz is edited by Joel Don, ISA’s social media community manager.

This automation industry quiz question comes from the ISA Certified Control Systems Technician (CCST) program. Certified Control System Technicians calibrate, document, troubleshoot, and repair/replace instrumentation for systems that measure and control level, temperature, pressure, flow, and other process variables. Click this link for more information about the CCST program.

When using the parity system to detect data transmission errors, the parity bit is set to a “1” or a “0” based on the content of the:

a) bits in the data word
b) start bit and bits in the data word
c) bits in the data word, including parity
d) bits in the data word, parity, and the stop bit
e) none of the above

Click Here to Reveal the Answer

The correct answer is A, bits in the data word. Parity is a simple method using a binary code (“1” or “0”) to detect data transmission errors by making the sum of the “1” bits in the source data either an odd or an even number. The calculated parity bit is then appended to the end of the data stream.

For example, if the following data word is to have “even parity,” the parity bit would be set to “1” in order for there to be an overall “even number” of bits set to “1”:

1 1 0 1 1 0 1                         parity bit = 1

The resulting data, with the parity bit, would be: 1 1 0 1 1 0 1 1 (total of six “1” bits).

The receiving device strips off the parity bit, recalculates the parity, and compares the result to the parity bit received. If it matches, it is assumed that the received data and the sent data match. If not, an error (parity error) is flagged. For communication to occur, both the sender and receiver must be configured for the same sense of parity (both odd or both even).

Since there are five “1” bits in the original word, the parity bit for “odd parity” is a “0.”

Reference: Goettsche, L.D. (Editor), Maintenance of Instruments and Systems, 2nd Edition

About the Editor
Joel Don is the community manager for ISA and is an independent content marketing, social media and public relations consultant. Prior to his work in marketing and PR, Joel served as an editor for regional newspapers and national magazines throughout the U.S. He earned a master’s degree from the Medill School at Northwestern University with a focus on science, engineering and biomedical marketing communications, and a bachelor of science degree from UC San Diego.

Connect with Joel
LinkedInTwitterEmail

 



Source: ISA News

My Journey on a ‘Yellow Brick’ Path to Becoming an ISA Fellow

The post My Journey on a ‘Yellow Brick’ Path to Becoming an ISA Fellow first appeared on the ISA Interchange blog site.

This guest blog post is part of a series written by Edward J. Farmer, PE, ISA Fellow and author of the ISA book Detecting Leaks in Pipelines. To download a free excerpt from Detecting Leaks in Pipelines, click here. If you would like more information on how to purchase the book, click this link. To read all the posts in this series, scroll to the bottom of this post for the link archive.

The fall of 2019 was a special time for me. I was honored to become an ISA Fellow at the ISA Leadership Conference in San Diego. There are wonderful pictures including my 12-year-old son watching intently, and the smiling faces of so many people basking in the intense moments that memorialize so much work, so much history!

When I was a young guy, not long out of college, I realized I was drawn into industrial automation. Magazine articles by now-ISA Fellow Francis Gregory Shinsky were inspiring and motivating and were an important part of getting me on my way. I remember my contract supervisor at Standard Oil of California, Dick Debolt, remarking on Greg’s work with Foxboro and opining that if they didn’t make it then it doesn’t exist. How far we’ve come over my nearly 50 years in industrial control and automation! What a role ISA, its members and its ISA Fellows had in all that! After all those years, books, and short courses here I am – one of those ISA Fellows!

A course that the U.S. Army taught me encouraged maintaining perspective, remembering where you came from, what you’re doing here, and where you’re going. When I was 10 my grandparents took me to their homes from the silver age in Western Colorado. They wanted me to understand how the two of them grew up and started their adult lives in Ouray and Silverton. I came to understand how the events of the times brought them west, first to Arizona and eventually Northern California. They helped me through some stepfather issues over the summer and when I returned home I went to a place of special significance to me and had a long talk with myself about the big issues in how I wanted my life to work out – not specifics, but the broader things, like finding and developing the life that was right for me, and living in accordance with my impression of the way that enabled the world and people in it to be all they can be.

I left home for college in 1966, the beginning of my Yellow Brick Road. Over the years I served in the U.S. Army, worked in hydroelectric generation, managed a systems integrator, and moved into private practice. I did a lot of automation work in water and wastewater, at Standard Oil of California (and of course Chevron) refineries, with ExxonMobil in process control work, and eventually many others, producing over 100 papers in various industry periodicals. As it turned out, it was a wonderful journey through amazing times animated by technology advancement unprecedented in human history. There is no better time to have been alive or working in engineering. ISA was always part of this for me and it felt so good to become an ISA Fellow with some of the people that were so instrumental in how my life turned out.

To answer Dorothy’s question from the Wizard of Oz, yes, there is another place over the rainbow. I went from being a very poor kid to a comfortable life of good, meaningful, and societally valuable work. Counting the two years of part-time work in an engineering job that I did while finishing college, I spent a half-century of good, interesting, engaging, and valuable work that increased my knowledge and awareness. My journey, my Yellow Brick Road, was truly an adventure. I loved it and am so glad it all worked out as I hoped and planned.

My company and its products are now part of TechnipFMC, and as I sit in my home office writing this, I am surrounded by memorabilia from all my time and adventures. There are college certificates, patents, a shelf of things I wrote, pictures of operations around the world, engineering registrations, a shelf of various military hats and helmets from my time in the Army and California National Guard, and a shelf of things I published. It feels like 50 years of home, or maybe 50 years on my journey; or maybe those are the same place.

A couple of months ago a young lady asked me for advice or an opinion about moving her life along its post-high school path to somewhere. I recalled that the Army placed me in command of a platoon when I was 20 and thought about how I felt then and how it served me. I told her my advice is: Be all you can be, leave what you encounter better than you found it, and stand for something. I also suggested maintaining a sense of both depth and diversity in your life’s activities.

I am so pleased to be writing this. I am so pleased to be here doing these things as well as remembering all those that came before. It is truly amazing and feel so good about it. The first picture I recall seeing of my mother is her in a Women’s Army Corps (WAC) uniform in World War II. When I was a kid it was on a shelf or dresser in some room that was special to her in some way. When she passed, I put it on top of my tallest bookcase, looking at me from across my room. I like to look up at her and think about the diverse life she lived. I think she would be pleased about how things turned out.

ISA is important to me and the ISA Fellow honor is a milestone. I am so glad to have made it to here, and to have so much to look back on, and so much hope for those moving along after me.

About the Author
Edward Farmer, author and ISA Fellow, has more than 40 years of experience in the “high tech” part of the oil industry. He originally graduated with a bachelor of science degree in electrical engineering from California State University, Chico, where he also completed the master’s program in physical science. Over the years, Edward has designed SCADA hardware and software, practiced and written extensively about process control technology, and has worked extensively in pipeline leak detection. He is the inventor of the Pressure Point Analysis® leak detection system as well as the Locator® high-accuracy, low-bandwidth leak location system. He is a Registered Professional Engineer in five states and has worked on a broad scope of projects worldwide. He has authored three books, including the ISA book Detecting Leaks in Pipelines, plus numerous articles, and has developed four patents. Edward has also worked extensively in military communications where he has authored many papers for military publications and participated in the development and evaluation of two radio antennas currently in U.S. inventory. He is a graduate of the U.S. Marine Corps Command and Staff College. During his long industry career, he established EFA Technologies, Inc., a manufacturer of pipeline leak detection technology.

Connect with Ed
48x48-linkedinEmail

 



Source: ISA News

Embedded Intelligent Adaptive PID Controller for an Electromechanical System [technical]

The post Embedded Intelligent Adaptive PID Controller for an Electromechanical System [technical] first appeared on the ISA Interchange blog site.

This post is an excerpt from the journal ISA Transactions. All ISA Transactions articles are free to ISA members, or can be purchased from Elsevier Press.

Abstract: In this study, an intelligent adaptive controller approach using the interval type-2 fuzzy neural network (IT2FNN) is presented. The proposed controller consists of a lower level proportional – integral (PI) controller, which is the main controller and an upper level IT2FNN which tuning on-line the parameters of a PI controller. The proposed adaptive PI controller based on IT2FNN (API-IT2FNN) is implemented practically using the Arduino DUE kit for controlling the speed of a nonlinear DC motor-generator system. The parameters of the IT2FNN are tuned on-line using back-propagation algorithm. The Lyapunov theorem is used to derive the stability and convergence of the IT2FNN. The obtained experimental results, which are compared with other controllers, demonstrate that the proposed API-IT2FNN is able to improve the system response over a wide range of system uncertainties.

Free Bonus! To read the full version of this ISA Transactions article, click here.

Enjoy this technical resource article? Join ISA and get free access to all ISA Transactions articles as well as a wealth of other technical content, plus professional networking and discounts on technical training, books, conferences, and professional certification.

Click here to join ISA … learn, advance, succeed!

Copyright © 2019 Elsevier Science Ltd. All rights reserved.



Source: ISA News

AutoQuiz: What Electrical Event Can Occur With a 24 VDC Open-Collector Output Sinking Configuration?

The post AutoQuiz: What Electrical Event Can Occur With a 24 VDC Open-Collector Output Sinking Configuration? first appeared on the ISA Interchange blog site.

AutoQuiz is edited by Joel Don, ISA’s social media community manager.

This automation industry quiz question comes from the ISA Certified Automation Professional (CAP) certification program. ISA CAP certification provides a non-biased, third-party, objective assessment and confirmation of an automation professional’s skills. The CAP exam is focused on direction, definition, design, development/application, deployment, documentation, and support of systems, software, and equipment used in control systems, manufacturing information systems, systems integration, and operational consulting. Click this link for more information about the CAP program.

In a 24 VDC open-collector output sinking configuration, which of the following could occur?

a) configuration increases the risk of electrostatic discharge (ESD) from static electricity
b) short circuit from the load device to ground can cause unintended actuation
c) the triode for alternating current (TRIAC) could remain on when the current (but not voltage) is zero unless a snubber network is used
d) inductive devices, such as motors, can generate back electromagnetic fields when turned on
e) none of the above

Click Here to Reveal the Answer

The correct answer is B, “Short circuit from the load device to ground can cause unintended actuation.” An NPN (sinking) open-collector, when “energized,” switches the load side of the relay (at terminal “A”) to ground (terminal “B”). In the drawing, the NPN open-collector is energized at its base with a light-emitting diode in an optically isolated programmable logic controller output card.

If the circuit below “short circuits” from the load device (relay) to ground, it would have the same effect as switching on the NPN open-collector, and the relay (load) would be actuated.

Note: Resistors that are typically installed in these circuits to regulate or limit current have not been shown for simplicity of illustration.

Reference: Nicholas Sands, P.E., CAP and Ian Verhappen, P.Eng., CAP., A Guide to the Automation Body of Knowledge. To read a brief Q&A with the authors, plus download a free 116-page excerpt from the book, click this link.

About the Editor
Joel Don is the community manager for ISA and is an independent content marketing, social media and public relations consultant. Prior to his work in marketing and PR, Joel served as an editor for regional newspapers and national magazines throughout the U.S. He earned a master’s degree from the Medill School at Northwestern University with a focus on science, engineering and biomedical marketing communications, and a bachelor of science degree from UC San Diego.

Connect with Joel
LinkedInTwitterEmail

 



Source: ISA News

How Visual Data Analytics Software Improves Natural Gas Well Site Efficiency and Reliability

The post How Visual Data Analytics Software Improves Natural Gas Well Site Efficiency and Reliability first appeared on the ISA Interchange blog site.

This post was authored by Andy Young, a research reactor controls engineer at the National Renewable Energy Laboratory. Previously he was the director of operations at Pioneer Energy

Pioneer Energy in Lakewood, Colo., is a service provider and original equipment manufacturer addressing gas processing challenges in the oilfield with a range of standard gas capture and processing units for tank vapors and flare gas. The company has a line of units that captures hydrocarbon vapors from crude oil tank batteries and extracts natural gas liquids (NGLs) at high yields, instead of sending these valuable commodities to combustion or venting them to the atmosphere.

This dramatically cuts emissions, meets U.S. Environmental Protection Agency Quad-O compliance standards, and provides a significant economic return. Another line of equipment (figure 1) captures and processes flare gas at the well site, producing NGLs and pipeline-quality lean methane and helping producers comply with regulations.

Oil and gas fields in North Dakota, Montana, and Colorado use this equipment at production well sites to capture methane and natural gas liquid streams. Pioneer operates and monitors these geographically disperse units from its headquarters. Operation and design teams monitor the equipment and analyze the results to make continuous improvements.

The FlareCatcher is powered with a natural gas generator, which is inside the white enclosure on the front of the trailer shown in figure 1. The fuel gas for this generator comes from any of the refined energy products made by the FlareCatcher, and this usage is only about 5 percent of the total energy of the gas processed by the equipment.

Figure 1. The FlareCatcher unit produces NGLs and pipeline-quality methane from flare gas. Visual data analytics software application helps improve efficiency, reliability, and performance.

 

The system has auxiliary (backup) batteries charged with a conventional battery tender powered by the primary generator or a solar panel. The auxiliary power system is required to keep communications alive when the system is not running due to maintenance, a component level failure, or insufficient gas flow from the site. Once the shutdown condition has been remedied, having communications available with headquarters allows remote startup.

Data from afar

The company has systems installed in the western U.S.-and future sites could be onshore or offshore anywhere in the world with cellular or satellite connectivity (figure 2). Alternately, a local radio network could be installed to get the data to a network hub.

Well-site data from the systems is sent to local data centers. This is a critical element of the modular architecture, because it leverages specialized resources. Data centers have extensive redundancies built into their power and networking services, absolutely required for operating critical hardware remotely. The company uses one data center in Denver and one in Dallas, and is investigating virtualization to add dynamic scaling and load balancing to field data gathering. Currently, all analog data is being transmitted at 1-second intervals. Discrete data is transmitted as it changes.

Although data was coming in from field sites to the data centers, there were no sophisticated data analysis tools. If engineers found themselves with some free time, they could manually load historical data into an Excel spreadsheet and calculate a few basic metrics. But Excel is not suitable for calculations of reasonable complexity, so much of the data gathered was not used as it could be. How could the company better analyze data from its far-flung operations?

Figure 2. Data can be acquired from well sites in any remote location via cellular or satellite communication.

 

Visual analytics application software

After analyzing various data analytics software packages, Visual data analytics application software was selected for utility and ease of use. This included components such as a graph database, time-series optimization, and a clean browser-based interface-plus advanced data analytics and information sharing capabilities. The visual analytics application enables the company to optimize the data stream. It can define simple computations to be performed at the edge to determine what data needs to be streamed to headquarters for analysis, and what data can be archived locally at the sites.

The visual analytics application software is currently being used to analyze and understand historical data, and to generate and define new rules for operating parameters (figure 3). Applications are endless. In a continuous improvement cycle, all data has potential value if it can be unlocked and leveraged. Now there is also an environment for experimentation and learning, and instant visual feedback so engineers can analyze complex data in a reasonable amount of time.

Figure 3. Engineers can monitor equipment at remote well sites with data analytics software, optimizing the data stream at the edge to focus on the most relevant information.

 

For example, key components of the technology is advanced refrigeration system designs that can be very sensitive to changing operational conditions. The visual analytics application software enables engineers to isolate these effects, identify their causes, and develop simple operational rules to extend the life of the capital investment.

One of the core value offerings is operating systems remotely. The software helps identify a problem with equipment in the field, so corrective action can be taken quickly. For instance, the company uses air-cooled cascade refrigeration systems. During hot days, discharge temperatures and pressures can rise to elevated levels, leading to hardware failure. Advanced metrics and predictive analytics detect this situation, so operators can intervene and turn down the system throughput until the condition has cleared.

All data from the well site is streamed to a centralized, secure data center, where the analytics server resides and accesses all field data. From there, the visual analytics application software interface is made available via a web proxy server. Technicians and engineers can access the data anywhere there is a network connection, including at the well site itself with a cellular hot spot (figure 4).

Figure 4. Well-site data is processed and made available via a web server. It is available anywhere in the world to engineers—even at the well site, as the author demonstrates.

 

Installation and startup

The visual analytics application software vendor performed two on-site training sessions in additional to remote installation and code development help sessions. The software application engineers identified an unusual issue causing an installation failure. The vendor’s subject-matter experts were made accessible through a web proxy server, which involves multiple port forwarding and security rules. Due to the many operations tools running on the server, there was a port conflict. A quick live session with the vendor identified the issue. Other than this issue, installation and startup proceeded as planned without a hitch.

Results

The single biggest outcome of the visual analytics application software installation is improved operational intelligence. The applications are simple to use, yet powerful visualization and analysis tools shed light on otherwise complex processes. There are many possibilities, and the only challenge now is deciding which mystery to tackle next, because the solution to any problem can be quickly determined. At this point, the next objective is to increase visual analytics application software uptake and adoption throughout the organization as a fundamental design and operations tool.

About the Author
Andy Young is a research reactor controls engineer at the National Renewable Energy Laboratory. Previously he was the director of operations at Pioneer Energy. At Pioneer Energy, he was in charge of all aspects of operating mobile gas processing solutions, including the controls, software, and network layers necessary to provide access to remote machine data. Andy has a B.S. in chemical and life science engineering from Virginia Commonwealth University.

Connect with Andy
LinkedIn

A version of this article also was published at InTech magazine



Source: ISA News

Primer: Essential Guide to Industrial Wireless Network Configuration and Layout Options

The post Primer: Essential Guide to Industrial Wireless Network Configuration and Layout Options first appeared on the ISA Interchange blog site.

This post was authored by Shuji Yamamoto, wireless promotion manager in Yokogawa’s New Field Development Center

One of the first steps when creating a new wireless instrumentation network using ISA100 Wireless, or any other industrial wireless network, is a site survey. This step is not part of any wireless standard, nor is it likely part of any network management platform, so it requires some creativity. Radio propagation patterns can be difficult to predict, but following a few basic design guidelines ensures a much higher level of success.

Some wireless consultants make the process very complex using simulations and reading test signals, but these often do not ultimately match the real world. Other approaches are simpler and involve taking a few distance measurements and establishing sight lines, which often works just as well. For this article, we will concentrate more on the latter, simpler approach.

ANSI/ISA-100.11a-2011 (IEC 62734), Wireless Systems for Industrial Automation: Process Control and Related Applications, networks are designed to support wireless field instrumentation. This protocol specification is part of the larger ISA100 Wireless series. Although network management platforms have an extraordinary capability for self-organization, this feature cannot overcome unreliable radio links.

But, the network management platform can use its diagnostic capabilities to measure the health of the communication and the devices. It can identify unreliable links so they can be fixed, and with improved communication, the network manager can reestablish a reliable link.

How signals propagate

Although it is not a perfect model, thinking of radio in the same way as visible light is accurate much of the time. Wireless networks depend largely on line of sight (LOS). If a wireless flowmeter is trying to transmit to a gateway in its LOS, the likelihood of a good link is very high. More potential obstructions are transparent to radio frequencies than visible light, but this is affected by frequency. A leafy tree is transparent to signals at 90 MHz, but 2.4-GHz signals will suffer some attenuation.

Metallic objects are the great enemy of radio propagation, but can also help under the right conditions, which is why refineries and chemical plants provide many challenges for wireless networks. In one case, a steel-shell storage tank can be helpful by reflecting a signal, while other times it is as an obstacle. Like visible light, much depends on the surface angles.

General wireless principles say to avoid metallic surfaces when placing antennas for field devices, such as process instruments and actuators, routers, and gateways. The best situation is to mount the antenna vertically so that it is unobstructed on all sides (figure 1). If a gateway is mounted next to a metallic pole, the signal will be attenuated, even on the side away from the pole. It is far better to move the antenna to the top of the pole, so it can extend into free space, or to extend the antenna mounting horizontally, so there is at least a 1-meter gap between the antenna and the pole.

Figure 1. For the best signal propagation, each antenna should be mounted vertically with at least 1 m of clear space around it horizontally. This normally means mounting the antenna as high on a structure as possible.

 

Understanding the Fresnel zone

Elevated antenna placement is important, because radio communication does not move in a tight beam like a laser. To send the signal from one point to another efficiently, some area in the shape of an ellipse is required. This area is called the Fresnel zone (figure 2). The amount of room available for the signal to spread has a huge effect on signal strength and the distance it can carry, since the longer the distance, the fatter the zone needs to be in the center. Anything violating the zone, which could even be the ground itself, attenuates the strength. Therefore, trying to squeeze a signal through a narrow space, even though it may allow direct LOS, can result in signal attenuation.

For example, where the LOS side clearance has an open space with a radius of 4 m, the communication range can be 500 m. However, when trying to send the signal through a more constricted area where the open space radius is only 2 m, the effective distance will be cut by 75 percent to 128 m. Having open, unobstructed space makes a huge difference, but this is typically a problem in most congested plant environments. This is why mounting devices and antennas as high as possible is so important.

Figure 2. Radio waves tend to propagate through an elliptical space formed between the two antennas. The longer the distance, the larger the required diameter at the center. This space should be as unobstructed as possible to avoid signal attenuation.

 

Meshing vs. routing devices

ISA-100.11a has mechanisms for device-to-device meshing, but the more desired network topology is one where a field device can communicate directly with the gateway, or directly to a router connected to the gateway (figure 3). The goal is to avoid the need for meshing device-to-device, because sending signals between multiple field devices slows down data movement and taxes the devices’ batteries.

To facilitate these transmissions, gateways and routers should be mounted as high as practical to clear any surrounding equipment and permit clear LOS connections. My company calls this practice of having a mesh of routers communicating above the plant equipment a sky mesh, and it takes advantage of more powerful transmitters than are practical for individual wireless field devices.

Placement of individual field devices is not as simple. Most native wireless devices, such as a differential pressure instrument, have an integral wireless transmitter and antenna (figure 4). This is very convenient, but can complicate signal propagation. Placement in the process piping or vessel often dictates where the device must be mounted, the antenna orientation, and the surrounding obstructions. Using an antenna extension can address these issues. Another alternative is to add a router mounted as near to the instrument as possible and clear of obstructions. If more than one instrument is in the same difficult location, a single router can service a group.

Figure 3. The gateway is the end point of the network, and is connected to the control and monitoring system via hard wiring. Routers serve as relay points, gathering information from the field devices and passing it to the gateway.

 

Figure 4. Having an antenna mounted on the field device is common, but placement of the field device may put it in a location prone to interference. An external add-on antenna may be needed to improve communication.

 

Laying out a network

Most networks are designed from two ends, the field and the control room. Field devices must be located according to their process function, which could easily be in a congested pipe jungle where equipment interferes with clear signal propagation. The final gateway is often placed near the control room, because it is hardwired to the control system. The network must bridge this gap.

Creating a sky mesh requires finding where it is practical to place routers. Ideally, these should be high off the ground and as close to the individual field devices as possible. Ensuring reliable communication between the field devices and the nearest sky mesh router may involve a secondary router in between to compensate for signal loss.

In most process plants, it is not difficult to find tall structures, such as distillation columns, but they may not be located where they are useful for router placement. Positioning antenna to avoid signal blockage problems associated with such large metallic structures can be tricky. As a rule of thumb, if the router is placed 30 m above the ground, it can reach individual field devices close to ground level up to 50 m away (figure 5). This assumes a few beneficial reflections, balanced against some obstructions from piping.

The connection from each field device to the closest router is the most challenging because it often has the most obstructions. Communication between routers and the gateway is easier to visualize and evaluate, since those components are mounted higher above the process equipment in more open space.

Figure 5. Routers in high positions can reach down to communicate with field devices closer to ground level. The practical area of coverage under favorable conditions is roughly a 90º to 100º cone, with the router as the cone’s apex.

 

Evaluating performance

The two most common measures of network performance are bit error rate (BER) and packet error rate (PER). The former uses predetermined bit patterns to check which are received incorrectly, a process requiring dedicated software on all the field devices, routers, and gateways. It must be performed as a specific test, sending the designated patterns.

PER performance measurements, on the other hand, deal with complete packets and can be done without special tools during normal communication. If a problem is developing, there will be a detectable change in the PER.

The most important indicator is determining how often packets get through correctly the first time. Getting the PER as low as possible is the objective, but this can only be done when all radio links are working reliably.

A well-designed ISA-100.11a wireless instrumentation network can operate as dependably as wired I/O in most applications. When the communication links connect reliably, latency will be minimized, allowing control room operators and other plant personnel to have all the information they need in a timely manner.

About the Author
Shuji Yamamoto is wireless promotion manager in Yokogawa’s New Field Development Center. He joined Yokogawa after completing a master’s degree in electronic engineering from Shinshu University with a specialty in high frequency research. He has had a variety of responsibilities with the company over his career, primarily related to wireless networking and IIoT.

Connect with Shuji
LinkedIn

A version of this article also was published at InTech magazine



Source: ISA News