Thursday, December 31, 2015

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

Tuesday, December 29, 2015

The Rotary Globe Control Valve

Neles Rotary 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".

Monday, December 14, 2015

Valves Designed for Severe Service. Not Just Heavy Duty

severe service control valve
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

Saturday, December 5, 2015

Closed Loop Control System Basics

closed loop control
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.

Friday, November 20, 2015

Safety Compliance White Paper for Solenoid Valves

ASCO Valve
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.

Friday, November 13, 2015

Eccentric Rotary Plug Control Valves

Eccentric plug valve
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.


Wednesday, November 4, 2015

Automation Competency Model Helps Guide Future Technical Workforce

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