Coriolis Flowmeter Reduces Sucrose Losses with Better Molasses Production at Sugar Mill

Molasses Production at Sugar Mill

A sugar mill typically loses between one and two percent of its incoming sucrose to factors such as poor clarification, sugar crystal elongation, reduced crystal growth rates, filter cake loss, and loss to molasses. Of these, loss to molasses is most significant — and one of the most difficult to prevent. Loss to molasses results from inaccurate flow measurement that causes more than the required amount of sucrose to pass into the molasses recipe. Wasting valuable sucrose can directly affect profitability of molasses batch yields, so new strategies to control this loss are constantly being investigated.

Improved control begins with a reliable measurement of molasses production, but getting that is indeed a challenge. Estimating undetermined sugar loss to within 0.1 percent, for example, requires molasses loss measurement that is accurate to at least one percent.

There are a number of methods that have been employed to measure molasses quantities in sugar mills around the world, each with distinct advantages and limitations. Measuring storage tank levels on a regular basis is probably the simplest method, but readings are inconsistent and unreliable. The error in the mass estimate affects the undetermined loss directly. Further complicating accuracy are chemical reactions that produce carbon dioxide, which affects both density and tank levels.

Another method is production tank dipping, which involves detecting changes in ow based on changes in torque at various measurement points. While this may be adequate for reporting on a volume basis, most molasses production balance is based on mass. Also, molasses is usually aerated, which creates two-phase flow conditions, further compromising density and accuracy.

Foxboro Coriolis Flowmeter

Engineers at this sugar mill compared measurements made by tank dipping and batch weighing to conventional and digital Coriolis measurements at various points over a three-year period. Years earlier, they installed a competitor’s conventional Coriolis meter. Shortly after, they installed a Foxboro CFT50 digital Coriolis transmitter from Foxboro in series with the existing unit. The Foxboro meter uses digital flowtube control that overcomes flow interruption or stalling caused by two-phase flow. And finally, a short time later, as a benchmark for accuracy, they installed a set of molasses batch scales. Valve leaks notwithstanding, they assumed that the scales would provide the most faithful measure of flow.

The measurements from tank dipping were ten to fifteen percent lower than estimates obtained from either of the Coriolis meters tested.

Later, with the batch scales installed, both Coriolis meters recorded consistently higher estimates than the scales readings. On average, the Foxboro meter gave readings that were three percent higher, and the conventional meter read nine percent higher.

It was clear that the Coriolis meters followed the batch scales much more closely. This strongly indicates the unreliability of tank dipping measurements and suggests that the Coriolis meters are also more responsive to real changes in flow rate. An unanticipated result also indicated that the digital Coriolis meter might be the most responsive to sudden changes in flow rate.

While acknowledging the need for additional study, the researchers concluded that Coriolis measurement is the only suitable alternative to batch scales for measuring sucrose loss to molasses. They found that the conventional Coriolis meter tended to estimate higher than the Foxboro Coriolis meter and that the Foxboro meter had a significantly faster response time in on/off applications.

Conductivity Sensors Improve Biodiesel Production Quality and Production

Biodiesel production improvement
with conductivity sensors.

Biofuel products are made from a variety of feedstocks, primarily soybean oil, vegetable oil and animal fat derivatives. Biodiesel is a safe alternative fuel replacement for traditional petroleum diesel.

The biodiesel production process is done through a chemical reaction that combines vegetable oil or animal fat as a raw stock, methanol, and a catalyst of sodium methylate in proper proportions. The process, called transesterification, involves chemically converting triglycerides to smaller methyl esters that resemble diesel fuel with extra oxygen atoms that make it oxygenated diesel fuel enabling it to burn cleaner.

Producing biodiesel fuel is a difficult task that requires precise separation at various stages. Effective separation is critical to the success of the process and the quality of the product.

The plant has four 20,000-gallon reactors and approximately 15 process vessels of various sizes, as well as large field storage tanks used in the delicate separation process.

When emptying the reactors its very important to know exactly where the interface is between the biodiesel and byproducts. If byproducts are left in the fuel, product quality standards are not met and material have to be reprocessed. If your pour out biodiesel, you’re throwing money down the drain.

Conductivity sensors (courtesy of Foxboro)

There are a number of ways to detect phase changes, but conductivity sensing seemed ideal for this application. A conductivity measurement system is relatively inexpensive, very clean and maintenance free, since there are no moving parts.

Foxboro, a world-class manufacturer of process control equipment was called in for a consultation. The initial application is in a batch mode where the company has a pump on the bottom of the reactor. Directly downstream of that pump is a “T” configuration that houses the Foxboro conductivity sensor. At this stage, the biodiesel company needs to separate glycerin, which has a relatively high conductivity, approximately 4,000 to 5,000 microsiemen/cm.  The Foxboro probe monitors the conductivity of the fluid passing by and, as the interface occurs, it immediately detects a dramatic drop in conductivity because the methyl ester phase has a conductivity of less than 20 microsiemen/cm. The conductivity sensor then triggers a signal to stop the pump and close the valve. The remainder of what is in the reactor is methyl ester that contains contaminants including excess methanol, glycerin, soaps, catalyst and other impurities.

The second application involves removing these components from the biodiesel fuel before it can be released as a final product. The crude biodiesel is mixed with water to scrub out the impurities, and then the water is allowed to settle to the bottom of the reactor. Because wash water has a high conductivity of about 2,500 microsiemen/cm, the Foxboro sensors can immediately detect the interface between methyl ester and wash water.

After the washing, the biodiesel goes to the final phase where a vacuum dehydrator warms the wet biodiesel and draws out any residual water. In this third application the Foxboro conductivity sensing probe is used to determine when the appropriate amount of water is removed. At that point what remains is finished biodiesel fuel.

Conductivity sensing technology allowed the successful automation of critical phase separation processes and will allow additional and ongoing process improvements such as automated and continuous processing, and further improvements in production efficiencies and more consistent product quality are expected.

Types of Pressure Measurements Used in Process Control

Pressure gauge
(courtesy of Ashcroft)

Pressure, the measure of a force on a specified area, is a straightforward concept, however, depending on the application, there are many different ways of interpreting the force measurement.

As with any type of measurement, results need to be expressed in a defined and clear way to allow everyone to interpret and apply those results correctly. Accurate measurements and good measurement practices are essential in industrial automation and process environments, as they have a direct effect on the success of the desired outcome.

When measuring pressure, there are multiple units of measurement that are commonly used. Most of these units of measurement can be used with the international system of units, such as kilo, Mega, etc.

This white paper (courtesy of Turck) will identify the various units of pressure measurement, while discussing when and why certain pressure measurements are used in specific applications.

Explanation of the Types of Pressure Measurements Used in Process Control from Mead O'Brien, Inc.

Cybersecurity: Seven Steps to Effectively Defend Industrial Control Systems

Seven steps toward industrial cybersecurity.

Cyber intrusions into US Critical Infrastructure systems are happening with increased frequency. For many industrial control systems (ICSs), it’s not a matter of if an intrusion will take place, but when. In Fiscal Year (FY) 2015, 295 incidents were reported to ICS-CERT, and many more went unreported or undetected. The capabilities of our adversaries have been demonstrated and cyber incidents are increasing in frequency and complexity. Simply building a network with a hardened perimeter is no longer adequate. Securing ICSs against the modern threat requires well-planned and well-implemented strategies that will provide network defense teams a chance to quickly and effectively detect, counter, and expel an adversary. This paper presents seven strategies that can be implemented today to counter common exploitable weaknesses in “as-built” control systems.

If system owners had implemented the strategies outlined in this paper, 98 percent of incidents ICS-CERT responded to in FY 2014 and FY 2015 would have been prevented. The remaining 2 percent could have been identified with increased monitoring and a robust incident response.

1. IMPLEMENT APPLICATION WHITELISTING

Application Whitelisting (AWL) can detect and prevent attempted execution of malware uploaded by adversaries. The static nature of some systems, such as database servers and human-machine interface (HMI) computers, make these ideal candidates to run AWL. Operators are encouraged to work with their vendors to baseline and calibrate AWL deployments.

Example: ICS-CERT recently responded to an incident where the victim had to rebuild the network from scratch at great expense. A particular malware compromised over 80 percent of its assets. Antivirus software was ineffective; the malware had a 0 percent detection rate on VirusTotal. AWL would have provided notification and blocked the malware execution.

2. ENSURE PROPER CONFIGURATION/PATCH MANAGEMENT

Adversaries target unpatched systems. A configuration/patch management program centered on the safe importation and implementation of trusted patches will help keep control systems more secure.
Such a program will start with an accurate baseline and asset inventory to track what patches are needed. It will prioritize patching and configuration management of “PC-architecture” machines used in HMI, database server, and engineering workstation roles, as current adversaries have significant cyber capabilities against these. Infected laptops are a significant malware vector. Such a program will limit connection of external laptops to the control network and preferably supply vendors with known-good company laptops. The program will also encourage initial installation of any updates onto a test system that includes malware detection features before the updates are installed on operational systems.

Example: ICS-CERT responded to a Stuxnet infection at a power generation facility. The root cause of the infection was a vendor laptop.

Use best practices when downloading software and patches destined for your control network. Take measures to avoid “watering hole” attacks. Use a web Domain Name System (DNS) reputation system. Get updates from authenticated vendor sites. Validate the authenticity of downloads. Insist that vendors digitally sign updates, and/or publish hashes via an out-of-bound communications path, and use these to authenticate. Don’t load updates from unverified sources.

Example: HAVEX spread by infecting patches. With an out-of-band communication path for patch hashes, such as a blast email, users could have validated that the patches were not authentic.

3. REDUCE YOUR ATTACK SURFACE AREA

Isolate ICS networks from any untrusted networks, especially the Internet.b Lock down all unused ports. Turn off all unused services. Only allow real-time connectivity to external networks if there is a defined business requirement or control function. If one-way communication can accomplish a task, use optical separation (“data diode”). If bidirectional communication is necessary, then use a single open port over a restricted network path.

Example: As of 2014, ICS-CERT was aware of 82,000 cases of industrial control systems hardware or software directly accessible from the public Internet. ICS-CERT has encountered numerous cases where direct or nearly direct Internet access enabled a breach. Examples include a US Crime Lab, a Dam, The Sochi Olympic stadium, and numerous water utilities.

4. BUILD A DEFENDABLE ENVIRONMENT

Limit damage from network perimeter breaches. Segment networks into logical enclaves and restrict host-to-host communications paths. This can stop adversaries from expanding their access, while letting the normal system communications continue to operate. Enclaving limits possible damage, as compromised systems cannot be used to reach and contaminate systems in other enclaves. Containment provided by enclaving also makes incident cleanup significantly less costly.

Example: In one ICS-CERT case, a nuclear asset owner failed to scan media entering a Level 3 facility. On exit, the media was scanned, and a virus was detected. Because the asset owner had implemented logical enclaving, only six systems were put at risk and had to be remediated. Had enclaving not been implemented, hundreds of hosts would have needed to be remediated.

If one-way data transfer from a secure zone to a less secure zone is required, consider using approved removable media instead of a network connection. If real-time data transfer is required, consider using optical separation technologies. This allows replication of data without putting the control system at risk.

Example: In one ICS-CERT case, a pipeline operator had directly connected the corporate network to the control network, because the billing unit had asserted it needed metering data. After being informed of a breach by ICS-CERT, the asset owner removed the connection. It took the billing department 4 days to notice the connection had been lost, clearly demonstrating that real-time data were not needed.

5. MANAGE AUTHENTICATION

Adversaries are increasingly focusing on gaining control of legitimate credentials, especially those associated with highly privileged accounts. Compromising these credentials allows adversaries to masquerade as legitimate users, leaving less evidence than exploiting vulnerabilities or executing malware. Implement multi-factor authentication where possible. Reduce privileges to only those needed for a user’s duties. If passwords are necessary, implement secure password policies stressing length over complexity. For all accounts, including system and non-interactive accounts, ensure credentials are unique, and change all passwords at least every 90 days.

Require separate credentials for corporate and control network zones and store these in separate trust stores. Never share Active Directory, RSA ACE servers, or other trust stores between corporate and control networks.

Example: One US Government agency used the same password across the environment for local administrator accounts. This allowed an adversary to easily move laterally across all systems.

6. IMPLEMENT SECURE REMOTE ACCESS

Some adversaries are effective at gaining remote access into control systems, finding obscure access vectors, even “hidden back doors” intentionally created by system operators. Remove such accesses wherever possible, especially modems as these are fundamentally insecure.
Limit any accesses that remain. Where possible, implement “monitoring only” access enforced by data diodes, and do not rely on “read only” access enforced by software configurations or permissions. Do not allow remote persistent vendor connections into the control network. Require any remote access be operator controlled, time limited, and procedurally similar to “lock out, tag out.” Use the same remote access paths for vendor and employee connections; don’t allow double standards. Use two-factor authentication if possible, avoiding schemes where both tokens are similar types and can be easily stolen (e.g., password and soft certificate).

Example: Following these guidelines would have prevented the BlackEnergy intrusions. BlackEnergy required communications paths for initial compromise, installation and “plug in” installation.

7. MONITOR AND RESPOND

Defending a network against modern threats requires actively monitoring for adversarial penetration and quickly executing a prepared response.
Consider establishing monitoring programs in the following five key places:

1. Watch IP traffic on ICS boundaries for abnormal or suspicious communications.
2. Monitor IP traffic within the control network for malicious connections or content.
3. Use host-based products to detect malicious software and attack attempts.
4. Use login analysis (time and place for example) to detect stolen credential usage or improper access, verifying all anomalies with quick phone calls.
5. Watch account/user administration actions to detect access control manipulation.

Have a response plan for when adversarial activity is detected. Such a plan may include disconnecting all Internet connections, running a properly scoped search for malware, disabling affected user accounts, isolating suspect systems, and an immediate 100 percent password reset. Such a plan may also define escalation triggers and actions, including incident response, investigation, and public affairs activities.
Have a restoration plan, including having “gold disks” ready to restore systems to known good states.

Example: Attackers render Windows®d based devices in a control network inoperative by wiping hard drive contents. Recent attacks against Saudi AramcoTMe and Sony Pictures demonstrate that quick restoration of such computers is key to restoring an attacked network to an operational state.

Defense against the modern threat requires applying measures to protect not only the perimeter but also the interior. While no system is 100 percent secure, implementing the seven key strategies discussed in this paper can greatly improve the security posture of ICSs.

DISCLAIMER

The information and opinions contained in this document are provided “as is” and without any warranties or guarantees. Reference herein to any specific commercial products, process, or service by trade name, trademark, manufacturer, or otherwise, does not constitute or imply its endorsement, recommendation, or favoring by the United States Government, and this guidance shall not be used for advertising or product endorsement purposes.

ACKNOWLEDGMENT

This document “Seven Steps to Effectively Defend Industrial Control Systems” was written in collaboration, with contributions from subject matter experts working at the Department of Homeland Security (DHS), the Federal Bureau of Investigation (FBI), and the National Security Agency (NSA).

Using Eductors for Non-Powered Tank Mixing

Eductor for tank mixing
(courtesy of Jacoby Tarbox)

An eductor is a pump that uses a fluid to perform the work of pumping another fluid (or solid). The fluid doing the work is termed the motive fluid, and the fluid being pumped is the suction fluid. The motive fluid employed can be liquid. gas or steam. The suction fluid can be liquid. gas or steam. Other names for eductors include jet pumps, ejectors, Venturi pumps, siphon pumps, steam siphons, and injector pumps. Eductors operate on basic principles of flow dynamics.

Eductors require no power, which means no moving parts. The design of the eductor creates pressure differential allowing fluid to flow naturally within the device - creating suction, mixing, and pushing the liquid throughout the tank.

In-line eductors are the next generation of jet pumps, ejectors, and Venturi pumps providing in-line mixing, pumping, or heating in various process lines. Eductors reduce costs as there are no moving parts and require no direct power.

The video below, while marketing oriented, does a great job at demonstrating how tank mixing is accomplished efficiently and thoroughly with an array of eductors by calculating tank size and volume along with material properties to develop a mixing profile.

For more information, contact:

Mead O'Brien
(800) 892-2769
www.meadobrien.com

Theory of Operation for MOVs (Motor Operated Valves)

Limitorque SMB MOV

This presentation, provided by the NRC, provides an introductory look at motor operated valves, with a focus on the manufacturer Limitorque. The document includes the theory of operation of MOVs, plus descriptions of valve types, such as gate, globe, ball, plug and butterfly.

This document also provides detailed descriptions of Limitorque SMB actuators and Limitorque SB actuators with full assembly and subassembly breakdown and illustrations.

NRC Course on Motor Operated Valves and Limitorque from Mead O'Brien, Inc.

Document provided by NRC.gov

Configuring a Foxboro PH10 Sensor Using the Foxboro 876PH Transmitter

pH and ORP Sensor
(courtesy of Foxboro)

The PH10 DolpHin^® Series pH Sensors and ORP10 DolpHin Series ORP Sensors are suitable for a wide range of pH and ORP measurement applications. They are designed for use with Foxboro^® brand 875PH, 873PH, and 873DPX Analyzers, and 876PH Intelligent Transmitters and 870ITPH Transmitters. Some can also be used with 873APH Analyzers. When used with 875PH Analyzers or 876PH and 870ITPH Transmitters, they provide the additional capability of on-line diagnostics to signal the user if any of several common sensor faults occur.

The sensors are available with a choice of temperature compensation and cable termination. They are available with an internal pre-amplifer for use up to 150 m (500 ft) and with a Smart sensor for use up to 100 m (328 ft) from the analyzer or transmitter. The sensors can be mounted to the process in a number of ways. They have a 3/4-inch external NPT connection on both the electrode and cable end. The sensors can be inserted directly into the process line or tank or mounted through a variety of accessories including bushings, tees, flow chambers, and ball valves/insertion assemblies.The sensors are available in both analog and Smart versions.

These industry-leading sensors are already proven in countless installations including chemicals, pulp & paper, all kinds of industry and municipal water/wastewater treatment, metals/mining, and food and dairy applications worldwide.

The Foxboro^® brand Model 876PH is a 2-wire loop powered intelligent transmitter that, when used with appropriate electrochemical sensors, provides measurement, local display, and transmission of pH, ORP (Oxidation-Reduction Potential), or ISE (Ion Selective Electrode) concentration. The transmitter outputs a HART digital signal and a 4 to 20 mA analog output. Versions are available for use with both analog and Smart (digital) sensors.

This video demonstrates how to correctly configure a Foxboro^® PH10 sensor using the Foxboro^® 876PH Transmitter.

Form ore information, contact:

Mead O'Brien

www.meadobrien.com

(800) 892-2769

The Rack and Pinion Style Pneumatic Valve Actuator

Rack & Pinion Actuator
(courtesy of Flowserve Automax)

Three primary kinds of valve actuators are commonly used: pneumatic, hydraulic, and electric.

Pneumatic actuators can be further categorized as scotch yoke design, vane design, and the subject of this post - rack and pinion actuators.

Rack and pinion actuators provide a rotational movement designed to open and close quarter-turn valves such as ball, butterfly, or plug valves and also for operating industrial or commercial dampers.

The rotational movement of a rack and pinion actuator is accomplished via linear motion and two gears. A circular gear, referred to a “pinion” engages the teeth of a linear gear “bar” referred to as the “rack”.

Pneumatic actuators use pistons that are attached to the rack. As air or spring power is applied the to pistons, the rack is “pushed” inward or “pulled” outward. This linear movement is transferred to the rotary pinion gear (in both directions) providing bi-directional rotation.

Visual of rack and pinion
(courtesy of Wikipedia)

Rack and pinion actuators pistons can be pressurized with air, gas, or oil to provide the linear the movement that spins the pinion gear. To rotate the pinion gear in the opposite direction, the air, gas, or oil must be redirected to the other sides of the piston, or use coil springs as the energy source for rotation. Rack and pinion actuators using springs are referred to as "spring-return actuators". Actuators that rely on opposite side pressurization of the rack are referred to as "direct acting".

Most actuators are designed for 100-degree travel with clockwise and counterclockwise travel adjustment for open and closed positions. World standard ISO mounting pad are commonly available to provide ease and flexibility in direct valve installation.

NAMUR mounting dimensions on actuator pneumatic port connections and on actuator accessory holes and drive shaft are also common design features to make adding pilot valves and accessories more convenient.

Fully automated valve with rack
and pinion actuator, solenoid, and
limit switch.

Pneumatic pneumatic rack and pinion actuators are compact and save space. They are reliable, durable and provide a good life cycle. There are many brands of rack and pinion actuators on the market, all with subtle differences in piston seals, shaft seals, spring design and body designs.

For more information on any pneumatic or electric valve automation project, contact:

Mead O’Brien, Inc.
www.meadobrien.com
10800 Midwest Industrial Blvd
St. Louis, Missouri 63132
Phone (314) 423-5161
Toll Free (800) 874-9655
Fax (314) 423-5707
Email: meadstl@meadobrien.com

Pneumatic Instruments

Pneumatic transmitters
(courtesy of Foxboro)

Air pressure may be used as an alternative signaling medium to electricity. Imagine a pressure transmitter designed to output a variable air pressure according to its calibration rather than a variable electric current. Such a transmitter would have to be supplied with a source of constant-pressure compressed air instead of an electric voltage, and the resulting output signal would be conveyed to the indicator via tubing instead of wires:

The indicator in this case would be a special pressure gauge, calibrated to read in units of process pressure although actuated by the pressure of clean compressed air from the transmitter instead of directly by process fluid. The most common range of air pressure for industrial pneumatic instruments is 3 to 15 PSI. An output pressure of 3 PSI represents the low end of the process measurement scale and an output pressure of 15 PSI represents the high end of the measurement scale. Applied to the previous example of a transmitter calibrated to a range of 0 to 250 PSI, a lack of process pressure would result in the transmitter outputting a 3 PSI air signal and full process pressure would result in an air signal of 15 PSI. The face of this special “receiver” gauge would be labeled from 0 to 250 PSI, while the actual mechanism would operate on the 3 to 15 PSI range output by the transmitter. As with the 4-20 mA loop, the end-user need not know how the information gets transmitted from the process to the indicator. The 3-15 PSI signal medium is once again transparent to the operator.

Typically, a 3 PSI pressure value represents 0% of scale, a 15 PSI pressure value represents 100% of scale, and any pressure value in between 3 and 15 PSI represents a commensurate percentage in between 0% and 100%. The following table shows the corresponding current and percentage values for each 25% increment between 0% and 100%. Every instrument technician tasked with maintaining 3-15 PSI pneumatic instruments commits these values to memory, because they are referenced so often:

Using the Foxboro model 13A pneumatic differential pressure transmitter as an example, the video below highlights the major design elements of pneumatic transmitters, including an overview of "maximum working pressure" versus "maximum measurement range" pressure.

The Foxboro model 13A pneumatic d/p cell transmitters measure differential pressure and transmit a proportional pneumatic output signal.

The information above is attributed to Tony Kuphaldt and is licensed under the Creative Commons Attribution 3.0.

Mead O'Brien: Steam and Hot Water System Experts

Let Mead O’Brien help you create a sustainable Steam Trap Management Process!

• Trained Survey Technicians 
• Traps located and identified, tagged with SS tag #, and data logged with up to 27 fields of useful data per trap 
• Executive summary, Failed trap report with steam & dollar losses, detailed Log sheets, and Recommendations are all provided in a professional report. 
• Monitoring options presented for critical service applications 
• Steam flow measurement design 
• Heat recovery potential 
• Training options in a live steam lab 

Realize the Savings Now!

• Reduce steam & condensate losses 
• Reduce loss of boiler chemicals 
• Improve heat transfer performance 
• Prevent coil and heat exchanger damage 
• Minimize water hammer hazards 

Mead O’Brien and Armstrong, more than 85 years of Steam & Hot Water System Optimization

• Steam Distribution
• Process Heat Transfer and Control
• Condensate Return
• Heat Recovery Opportunities
• Process, Ambient & Combustion Air
• Steam Trap Surveys & Database Creation 
• Humidification Assessment
• Application issues
• - Coil Freezing Issues
• - Poor Heat Transfer & Steam Control - Water Hammer Issues
• - High Backpressure
• Steam & Condensate Measurements, Control & Monitoring

Learning Systems:

• Armstrong University
• Over 125 web-based courses 
• Mead O’Brien Live Steam Lab
• Content Tailored for Plant Need

Steam Trap Testing Guide for Energy Conservation

Annual steam trap testing schedule

Below is a steam trap testing guide (courtesy of Armstrong International) to maximize efficiency and conserve energy. This guide discusses:

• Steam Trap Testing Procedure 
• Tips On Listening 
• Inverted Bucket 
• Float & Thermostatic Trap 
• Disc Trap 
• Thermostatic Trap 
• Sub-Cooling Trap 
• Traps on Superheated Steam

CAUTION: Valves in steam lines should be opened or closed by authorized personnel only, following the correct procedure for specific system conditions. Always isolate steam trap from pressurized supply and return lines before opening for inspection or repair. Isolate strainer from pressurized system before opening to clean. Failure to follow correct procedures can result in system damage and possible bodily injury.

Steam Trap Testing Guide for Energy Conservation from Mead O'Brien, Inc.

Steam System Condensate - Save Big by Managing its Proper Return

Recover/return steam condensate

An often overlooked place to find savings in the operation of a manufacturing plant is the steam condensate return system. Returning condensate to the boiler feedwater system saves energy by returning pre-heated water, thus requiring less energy to maintain the feed water temperature. Furthermore, condensate is pre-treated, eliminating the need for additional expensive treatment.

Steam use in modern plants is everywhere. The condensate derived from its use is an asset that needs to be recycled. Older steam systems may have poor condensate return piping, or none at all. For these situations, creating or extending return lines should be considered. Steam traps in older systems are also suspect. Older traps are not as efficient or reliable as newer designs.

According to Armstrong International’s Senior Utility Systems Engineer Novena Iordanova, steam traps are very important in the condensate return/feedwater cycle. She believes the first purpose of a steam system is to deliver steam to a users defined area of need, and second, to return the resulting condensate back to the boiler. Unfortunately, in many cases the second goal is overlooked.

In older plants, a complete steam system evaluation, and many times an overhaul, is required. Professionals should be called in as plant maintenance staff typically doesn’t have the expertise required. The reasons for steam system degradation are common in the life cycle of plant operation. Over time, plant upgrades, new lines, expansion, and new equipment can have a significant detrimental effect on condensate return systems. The focus usually goes to the main headers and distribution, but condensate return doesn’t receive the same attention. The result can be a steam system that is no longer efficient - meaning high back pressures, water hammer, broken or freezing pipes, and leaks. At that point, the plant needs professional help for a complete system review.

Steam trap
(courtesy of Armstrong)

The most important player in condensate recovery is the steam trap. Steam traps play the critical role of separating steam and condensate at the moment its formed. Traps discharge the condensate downstream to the boiler for reuse. Proper sizing, installation, and maintenance from the start will save huge amounts of money in terms of energy savings and maintenance time.

Frequent and regular inspections of steam traps are essential, but in reality they are many times postponed or rescheduled. Steam trap inspection is tough work. Traps are usually located in hard to see, hot, and tight areas. Over time, the difficulty (combined with the perceived low priority) degenerates to spotty inspection routines, higher trap fail rates and higher steam costs.

The good news is that steam trap monitoring systems now exist that can monitor the performance of steam traps and alert maintenance when things start to deteriorate. Steam trap monitoring systems report conditions that point to filature, and also alarm when things break down. Accordingly, maintenance is in a position to take preventive action, or make swift repairs. Any plant with a considerable number of stream traps should strongly consider deploying a steam trap monitoring system.

Steam trap monitoring systems monitor the thermal and acoustic characteristic of the trap and report any significant changes. Today many monitoring systems are wireless, and many operate on common plant communication systems such as WirelessHART, a communication protocol gaining worldwide acceptance.

Its important to mention here though, the on the most common mistake plant personnel make when it comes to their system is also one of  the most obvious - insulation. The use of high quality, well maintained insulation, installed to allow access to steam components is critical. The energy savings alone from well insulated pipes and traps is argument enough for making the initial time and dollar investment for proper insulating.

If you’re a plant manager and are looking for significant measurable and meaningful ways to lower energy costs, you must consider a well planned and well executed steam trap management program.

Happy New Year from the Mead O'Brien Team

Everyone at Mead O'Brien would like to wish all of our customers, vendors, suppliers, families and friends a very happy, healthy and prosperous 2016!

We look forward to serving our customers and working alongside you for our mutual success and growth.

Cheers!
The Mead O'Brien Team

The Rotary Globe Control Valve

Neles Rotary Control Valve

Neles, a division of Metso, offers their "RotaryGlobe" control valve designed to control a wide range of process liquids, gases and vapors. Its provides reliable and rugged construction and is available with a variety of different trim choices.  An excellent candidate for general, difficult and even severe service control valve applications for many industries including chemical, petrochemical, water treatment, pulp and paper, and power generation. The Neles RotaryGlobe valve provides excellent control accuracy with the inherent benefits of a rotary valve. The optimized design results in reliability and control stability and also reduces lifetime costs and maintenance needs.

See the video below for a "look inside".

Valves Designed for Severe Service. Not Just Heavy Duty

High performance butterfly
valve (Jamesbury)

From time to time, industrial process control applications involve very stringent and challenging performance requirements for the valves, process piping, and instruments that are part of the control loop. Control valves are a significant example where the impact of extreme fluid conditions require careful design and selection consideration to assure proper performance and safety levels are maintained in a predictable way.

Severe service is a term that describes valves used in application at the extremes of pressure, temperature, cycling, and material compatibility. While there are plenty of published and accepted standards for industrial valves, one does not exist to precisely define a severe service valve.


So, what then defines the selection of severe service valves, as opposed to general purpose valves?

There are a number of basic selection criteria that might point you in that direction, but in general they are:

• Very extreme media or environmental temperature
• High pressure drop operation that may cause cavitation
• Rapid and extreme changes to inlet pressure
• Certain types or amounts of solids contained in the fluid
• Highly corrosive, or erosive process 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 more involved assessment of the fluid conditions and commensurate valve requirements is needed. The key element for a specifier is to recognize when conditions are apparent that might 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 a severe service condition is identified, a careful analysis of the possible operating conditions will reveal the performance requirements for the valve.

When in doubt, its critical to discuss your special requirements with an experienced product application specialist. They have access to technical resources that can help with selecting the right valve components to meet your severe service applications.

For more information contact:

Mead O'Brien
(800) 892-2769

www.meadobrien.com

Closed Loop Control System Basics

Closed loop diagram

The video below explains the concept of a closed loop control system, using a steam heat exchanger and food processing application as an example.

A closed loop control system uses a sensor that feeds current system information back to a controller. That information is then compared to a reference point or desired state. Finally, a a corrective signal is sent to a control element that attempts to make the system achieve its desired state.

A very basic example of a temperature control loop includes a tank filled with product (the process variable), a thermocouple (the sensor), a thermostat (the controller), and a steam control valve feeding a tubing bundle (the final control element).

The video outlines all the major parts of the system, including the measured variable, the set point, the controlled variable, controller, error and disturbance.

Safety Compliance White Paper for Solenoid Valves

Discussion of safety when
selecting solenoid valves.

(White paper courtesy of ASCO Valve)

Regulatory modifications have raised important issues in design and use of industrial safety systems. Certain changes in IEC 61508, now being widely implemented, mean that designers and users who desire full compliance must give new consideration to topics such as SIL levels and the transition to new methodologies. 

In particular, these issues can impact users’ selection of solenoid valves and prepackaged redundant control systems (RCS) for implementation in a safety instrumented system (SIS). Such selections may also be affected by how experienced valve suppliers are at dealing with complex new compliance methodologies.

These issues are especially applicable to the oil, gas, chemical, and power industries - in applications such as safety shutdown systems, boilers, furnaces, high-integrity protection systems (HIPS), and more. They’re of concern to safety engineers and reliability engineers, as well as to process engineers, engineering executives, and plant managers.

This report will address these issues in developing a compliant SIS using valves and RCSs. Making the right choices in safety system planning and in valve supplier selection can affect design time, costs, and effort — as well as the safety of the plant itself.

Effective Compliance with IEC 61508 When Selecting Solenoid Valves for Safety Systems from Mead O'Brien, Inc.

Eccentric Rotary Plug Control Valves

Eccentric plug valve
(courtesy of Neles/Metso)

A plug valve is typically a quarter-turn (90 deg rotation) on-off valve, while eccentric plug valves are often used for control applications. The plug may be cylindrical or tapered, and may be designed with a variety of port patterns. End connections are typically flanged, hub type, or butt weld.

Eccentric rotary plug valves are designed for liquid, gas, vapor and slurry control in general and demanding applications. They provide excellent control performance, and their capability to handle impure fluids makes them well suited in refining, petrochemical, chemical, natural gas, and fertilizer manufacturing applications.

The design of an eccentric plug valve uses a modified plug design (basically a plug cut in half) which is well suited for applications that require a higher seating force, but with minimal friction when cycling from open to closed position. Eccentric plug valves also provide improved shut off capabilities without significant increases in operating torque. This style valve is used for a wide range of flow control and isolation applications including clean water, dirty water, sewage, sludge, and slurries.

Automation Competency Model Helps Guide Future Technical Workforce

Author, Stephen R. Huffman, Vice President, Marketing and Business Development, at Mead O’Brien, Inc.

Published: InTech Magazine, July-Aug 2015

Eight years ago, the Automation Federation (AF) delegation told an audience at the Employment and Training Administration (ETA) about the people practicing automation careers in industry. Not long before our visit, the ETA, part of the U.S. Department of Labor (DOL), had worked with the National Institute of Standards and Technology (NIST) to develop a “competency model” framework based on the needs of advanced manufacturing. The ETA was eager to engage AF and ISA to use our tiered framework to develop a competency model for the automation profession.

After developing the preliminary model, hosting subject-matter expert (SME) meetings facilitated by the DOL to finalize our work, and then testing the model with several automation managers against their own criteria for validity, we rolled out the Automation Competency Model (ACM) to educators, government, and industry in 2008. Since then, it has been a tool for educators and parents to show students what automation professionals do, management to understand the skill sets their employees need to be effective and to use as a tool for gap analysis in reviews, program developers to create or alter curricula for effective education and training, and lawmakers to understand how U.S. manufacturing can be globally competitive and the jobs needed to reach that goal.

In the lower tiers, the model identifies necessary soft skills, including personal effectiveness, academic, and general workplace competencies. Automation-specific work functions, related competencies, and references (e.g., standards, certifications, and publications) are detailed in tier 5. In short, the model stakes out our professional territory and serves as a benchmark for skill standards for all aspects of process and factory automation. Previously, parts of the academic community and some U.S. lawmakers and agencies had the misconception that industrial automation and information technology (IT) are synonymous. Although there has been some convergence between IT and operational technology (OT), much of that perception has changed. OT-based industrial automation and control systems (IACS) were a focus in the recent cybersecurity framework development organized by NIST in response to the presidential executive order on cybersecurity for critical infrastructure.

The ACM has been a great tool for the AF to use to draw new organizational members and working groups, who visualize the big picture in automation career development. Also, we are telling our story and forming partnerships with science, technology, engineering, and math (STEM) organizations such as FIRST and Project Lead the Way. Since forming in 2006, AF now has 16 members representing more than 500,000 automation-related practitioners globally. After two three-year critical reviews, the ACM is still the most downloaded competency model on the DOL website. As a result of our work in creating the ACM and the IACS focus in cybersecurity framework meetings, the DOL asked AF to review a heavily IT focused Cybersecurity Competency Model. After adding IACS content and the philosophy of plant operation (versus IT) cybersecurity, the model released was a much stronger tool with wider applicability.

Recently, ISA, as a member of the American Association of Engineering Societies (AAES), presented the development of the ACM to AAES leadership as a way to provide tools for lifelong learning in the engineering profession. AF/ISA was once again invited to work with the DOL and other AAES member societies to lead in developing an Engineering Competency Model. The model framework and our experience in ACM development enabled us to identify the front-end skills, necessary abilities, knowledge to be developed, and academic prerequisites for any of the disciplines, plus industry-wide competencies from the perspective of all engineering-related plant functions: design, manufacturing, construction, operations and maintenance, sustainability and environmental impact, engineering economics, quality control and assurance, and environmental health and safety—with emphasis on cyber- and physical security, and plant safety and safety systems.

Now the societies dedicated to each vertical discipline listed in tier 5 will begin to identify all critical work functions, detail all competencies within each function, and note the reference materials. It is important for the participants to see the big picture, consider the future, and keep an open mind; agreement typically comes easily when SMEs participate with that mindset. Once the model through tier 5 is complete, job titles and job descriptions are created. When the DOL accepts the model, the U.S. government officially recognizes these positions. We hope the emerging Engineering Competency Model will be a great tool to address the overall skilled worker shortage. If the automation model is any indication, the new engineering model will have a large impact on achieving the skilled workforce goal.

Suggestions for An Efficient Industrial Steam System

(image courtesy of OSHA.gov)

Here is a video, courtesy of Armstrong International, which provides a broad overview, and suggestions for proper use, of the key components of a well designed steam system.  Covered in this video are:

• 4 basic components of a steam system
• Water-side care
• Steam mains
• Drip legs and drip traps
• Branch piping, or runouts
• Non-condensible gases
• Proper selection of trap type and size
• Thermostatic and thermodynamic traps
• Thermostatic air vents
• Vacuum breakers
• Condensate management
• Heat exchangers
• Return lines

For more information on any steam or hot water system, contact:

Mead O'Brien
(800) 892-2769
www.meadobrien.com

Innovative Pressure Transmitter Automatically Selects Calibration Range

Foxboro S Series

Typical 2-wire intelligent transmitters require the operator to manually program and use a single calibration range suited to the specific application. Not anymore. A winner of a 2015 Flow Control Innovation Award has come up with a significant change in transmitter set-up.

Foxboro, through its patented “Foxcal” firmware allows the Foxboro models IDP10S, IGP10S, IAP10S transmitters to automatically select and use any of 11 preset calibration ranges (stored in firmware). These calibration ranges cover the full pressure range of the transmitter. Upon installation, the S Series transmitter automatically selects the appropriate calibration range based on application inputs; and, if application inputs change, automatically transitions to another, more appropriate calibration range – all while maintaining a reference accuracy of 0.05%.

It is the first pressure transmitter to incorporate not only multiple calibration curves, but the ability to automatically select and transfer between them in real time. With the new technology, users have a wide-range capability with high reference accuracy for all industries requiring precise differential, gauge, and absolute pressure measurement. Additional benefits are inventory reduction and simplified tech training. Because of their wide turndown range with such high reference accuracy, adopting one model of S Series transmitter eliminates the need to inventory, learn, and maintain multiple transmitter models that handle more limited ranges (e.g., 150 psi, 800 psi, 4000 psi).

The Foxboro IDP10S datasheet can be downloaded here.

Or, you can review it online below:

Foxboro IDP10S Intelligent Transmitter from Mead O'Brien, Inc.

For more information, contact:
Mead O’Brien
(800) 892-2769
sales@meadobrien.com
www.meadobrien.com

Cybersecurity, ISA, and Automation Federation and How We Got Here

Author, Stephen R. Huffman, Vice President, Marketing and Business Development, at Mead O’Brien, Inc.

Published: InTech Magazine, May-June 2015

Cybersecurity and
Automation

Technical leaders had the foresight to create the ISA99 standards committee back in 2002. They recognized the need for cybersecurity standards in areas outside of the traditional information technology (IT), national security, and critical infrastructure areas of concentration at the time. In the following years, a number of ISA99 committee members spent time and effort advocating and even testifying on Capitol Hill about our profession, which was not well defined, and our cybersecurity efforts therein, which were not well discerned from IT perceptions.

When Automation Federation (AF) refocused its efforts in 2007 with both automation profession advocacy and industrial automation and control system (IACS) cybersecurity as two of its strategic imperatives, we ventured forth to Capitol Hill with a message and a plan. We found that in general our lawmakers equated process and industrial automation as “IT” and thought that IT was already addressing cybersecurity in terms of identity theft and forensics, and that the Department of Defense was handling cyberprotection for national security. For the next several years, AF built its story around cyberthreats in the operational technology (OT) area and how ISA99 through its series of standards, technical reports, and work group output was providing guidance for asset owners, system integrators, and control system equipment manufacturers specifically for securing IACS.

The operating philosophy of IT cybersecurity versus OT cybersecurity is quite different. Although the approach of shutting down operations, isolating cybersecurity issues, and adding patches may work well to mitigate IT breaches, the same cannot be said for operating units in a real-time process. In short, it really is not feasible to “reboot the plant.” The message resonated enough for us to help create the Liebermann-Collins Cybersecurity Senate Bill introduced in 2012, but opposition (more political than reasonable) doomed this first effort.

In 2013, the President issued Executive Order 13636 for enhancing cybersecurity protection for critical infrastructure. It included directing the National Institute of Science and Technology (NIST) to establish a framework that organizations, regulators, and customers can use to create, guide, assess, or improve comprehensive cybersecurity programs. Of the more than 200 proposals submitted by organizations receiving a request for proposal, almost all were IT-based. The AF/ISA submittal took the perspective of operational technology backed by the strength of the existing ISA99 set of standards. After a set of five framework meetings of invited participants, including the AF “framework team,” over the course of 2013, the OT and IACS teams were much more successful in defining the needs, and the automation message was much better understood. NIST personnel with legislative experience with AF on the 2012 Senate bill understood that private industry is a key piece of the cybersecurity and physical security puzzle.

AF organized a series of NIST framework rollout meetings in 2014 around the country with attendees from the AF team, NIST, and the White House. The meetings were hosted by state manufacturing extension partnerships, which are state units of NIST. After these meetings and more work with Senate lawmakers, a bipartisan Senate bill, The Cybersecurity Enhancement Act, was signed by the President and put into law in December 2014 (www.congress.gov/bill/113th-congress/senate-bill/1353). In summary, the act authorizes the Secretary of Commerce through the director of NIST to facilitate and support the development of a voluntary, consensus-based, industry-led set of standards and procedures to cost effectively reduce cyberrisks to critical infrastructure. As you can imagine, ISA99, now IEC/ISA 62443, will play a more prominent role in securing the control systems of industry in the future through a public-private information-sharing partnership. Thanks for the foresight and fortitude of the ISA99 standards committee.

The Steam Table, Terms and Heat Transfer Concepts

Steam Table, courtesy of
Armstrong International
(click image for larger view)

Here are some basic steam terms associated with the Steam Table (left). Below is a slideshow of basic heat transfer concepts.

Saturated steam is pure steam at the temperature that corresponds to the boiling temperature of water at the existing pressure.

Absolute and Gauge Pressures
Absolute pressure is pressure in pounds per square inch (psia) above a perfect vacuum. Gauge pressure is pressure in pounds per square inch above atmospheric pressure, which is 14.7 pounds per square inch absolute. Gauge pressure (psig) plus 14.7 equals absolute pressure. Or, absolute pressure minus 14.7 equals gauge pressure.

Pressure/Temperature Relationship
For every pressure of pure steam there is a corresponding temperature. Example: The temperature of 250 psig pure steam is always 406°F.

Heat of Saturated Liquid
This is the amount of heat required to raise the temperature of a pound of water from 32°F to the boiling point at the pressure and temperature shown. It is expressed in British thermal units (Btu).

Latent Heat or Heat of Vaporization
The amount of heat (expressed in BTU) required to change a pound of boiling water to a pound of steam. This same amount of heat is released when a pound of steam is condensed back into a pound of water. This heat quantity is different for every pressure/temperature combination.

Total Heat of Steam
The sum of the Heat of the Liquid and Latent Heat in Btu. It is the total heat in steam above 32°F. Specific Volume of Liquid. The volume per unit of mass in cubic feet per pound.

Specific Volume of Steam
The volume per unit of mass in cubic feet per pound.

Basic Heat Transfer Concepts from Mead O'Brien, Inc.

For more information about any commercial or industrial steam or hot water systems, contact:

Mead O’Brien, Inc.

10800 Midwest Industrial Blvd

St. Louis, Missouri 63132

Phone (314) 423-5161

Toll Free (800) 874-9655

Fax (314) 423-5707

Email: sales@meadobrien.com

www.meadobrien.com

Product Update - New Valve Actuator Series From Limitorque

New Limitorque CEA Series Valve Actuator
Courtesy Flowserve Corp.

Industrial process control encompasses a broad range of fluid handling operations. A significant part of fluid control is accomplished by valves, many of which are operated automatically through the use of actuators. Actuators are mounted on valves in place of, or in addition to, a handwheel, lever, or other manual means of opening and closing the valve. With an actuator installed, a control signal can be transmitted from a remote source to the actuator, commanding a change in valve position, and the actuator will respond by converting some form of connected energy into mechanical motion that positions the valve accordingly.

Modern actuators are increasingly endowed with functions that provide information to the process operator, closing the loop with feedback that confirms the valve position, suitability of the energy supply to the actuator, and a range of other specialized data points.

An eternal desire of all process operators is a reduction in whatever level of maintenance that is currently required to keep everything operating. Maintenance is costly and time consuming, a set of many specialized tasks, each with a probability of not being completed properly.

Flowserve Corporation, under their well known Limitorque brand, has designed and launched a new series of electric actuators, the CEA Series, that provide real benefits for operation and maintenance in light-to-medium duty applications. Some of the highlights....

• Auto calibration and a user-friendly HMI provide optimized commissioning. Standard diagnostics include torque monitoring and actuator temperature, with early warning detection of undesirable conditions and an alarm output.
• Application specific brushless DC motors and worm gear drives reduce downtime. Tests have demonstrated reliability of up to 250,000 cycles. Modulating service can provide 1800 starts per hour with 0.1% position accuracy.
• Suitable for applications with rotary duty requirements of 90 and 180 degrees, as well as multi-turn duty to 20 turns.
• Available through a network of professional industrial process control distributors, with application assistance and product expertise.
• CEA is fully qualified to NEMA Type 4, 4X and6, IP66/68 Class 1, Div 1 and 2, Gps B,C,D (CSA,FM) and ATEX II 2G Ex d IIB +H2 T4: IECEx II 2G Ex d IIB +H2 T4.

The CEA actuator is available in seven sizes and five variants, serving torque requirements up to 15,000 in-lbs (1695 Nm). Contact a product specialist to find out more about this new product and discuss your potential applications.

Limitorque CEA Actuator Data Sheet from Mead O'Brien, Inc.

StoneL Axiom Limit Switch as Your Valve Automation Plant Standard

This video presents the StoneL Axiom limit switch as a strong plant standardization contender for all your valve automation needs.

The Axiom not only has all components incorporated integrally, it is a space efficient design utilizing the most flexible components for most applications: 20-125 VAC or DC monitoring feedback and solenoid control; 5-way, 2-position solenoid control with selection for either direct acting or spring return actuators in two Cv flow capacities for a wide range of actuators; bus communication modules and low power solenoid valves, re-breather solenoid functions, and manual override, all in a very rugged package.

For more information, contact:
Mead O'Brien
(800) 892-2769
www.meadobrien.com

Welcome to Mead O'Brien's Steam, Valve, Process Control, and HVAC Blog

Welcome and thanks for visiting. We established this blog as a means to provide educational information in the field of steam management, industrial hot water systems, industrial valves, and process instruments.

Our weekly posts will attempt to teach the reader something new and interesting in the field of industrial control and HVAC.

We hope you enjoy our content and please visit back often.