Showing posts with label actuation. Show all posts
Showing posts with label actuation. Show all posts

Thursday, April 13, 2017

Understanding Industrial Valve Actuators

Automated Pneumatic Ball Valve
Automated Pneumatic
Ball Valve (Jamesbury)
Valves are essential to industries which constitute the backbone of the modern world. The prevalence of valves in engineering, mechanics, and science demands that each individual valve performs to a certain standard. Just as the valve itself is a key component of a larger system, the valve actuator is as important to the valve as the valve is to the industry in which it functions. Actuators are powered mechanisms that position valves between open and closed states; the actuators are controllable either by manual control or as part of an automated control loop, where the actuator responds to a remote control signal. Depending on the valve and actuator combination, valves of different types can be closed, fully open, or somewhere in-between. Current actuation technology allows for remote indication of valve position, as well as other diagnostic and operational information. Regardless of its source of power, be it electric, hydraulic, pneumatic, or another, all actuators produce either linear or rotary motion under the command of a control source.

Thanks to actuators, multiple valves can be controlled in a process system in a coordinated fashion; imagine if, in a large industrial environment, engineers had to physically adjust every valve via a hand wheel or lever! While that manual arrangement may create jobs, it is, unfortunately, completely impractical from a logistical and economic perspective. Actuators enable automation to be applied to valve operation.
Pneumatic actuator
Pneumatic actuator
(Jamesbury Quadra-Powr

Pneumatic actuators utilize air pressure as the motive force which changes the position of a valve. Pressurized-liquid reliant devices are known as hydraulic actuators. Electric actuators, either motor driven or solenoid operated, rely on electric power to drive the valve trim into position. With controllers constantly monitoring a process, evaluating inputs, changes in valve position can be remotely controlled to provide the needed response to maintain the desired process condition.

Manual operation and regulation of valves is becoming less prevalent as automation continues to gain traction throughout every industry. Valve actuators serve as the interface between the control intelligence and the physical movement of the valve. The timeliness and automation advantages of the valve actuators also serve as an immense help in risk mitigation, where, as long as the system is functioning correctly, critical calamities in either environmental conditions or to a facility can be pre-empted and quickly prevented. Generally speaking, manual actuators rely on hand operation of levers, gears, or wheels, but valves which are frequently changed (or which exist in remote areas) benefit from an automatic actuator with an external power source for a myriad of practical reasons, most pressingly being located in an area mostly impractical for manual operation or complicated by hazardous conditions.
Electric Actuator
Electric Actuator
(Limitorque)

Thanks to their versatility and stratified uses, actuators serve as industrial keystones to, arguably, one of the most important control elements of industries around the world. Just as industries are the backbones of societies, valves are key building blocks to industrial processes, with actuators as an invaluable device ensuring both safe and precise operation.

Thursday, March 30, 2017

Selecting the Right Valve Automation Partner for the Power Industry

power industry valve automation
Electrically automated gate valve
in generating facility.
Having knowledgeable, experienced and skilled vendor-partners is crucial in mitigating safety, environmental, and health risks, as well as meeting power generation facility construction and production goals. Partnering with the right valve automation company means that you will have industry experts there to ensure the success of your project, meeting your budgetary and performance goals, and passing critical know-how along to your staff.

But what should you look for in a valve automation partner?

Understanding and Meeting Expectations
Your valve automation partner needs to understand your industry, the application, and the upstream and downstream processes affected by the automated system being installed. Your partner must have a full understanding of all types of valve automation, including pneumatic, hydraulic, electro-hydraulic, and electric actuation. A full understanding of the morass of technical and administrative requirements is critical. These include a knowledge of applicable codes, industry standards, environmental concerns, maintenance requirements, back-up systems, and emergency processes. A strong candidate will consider all of these factors for every power plant valve automation job.

Engineering, Experience, and Precision
Qualified engineering staff and experience are critically important factors in selecting your valve automation partner. A qualified partner should have engineering staff with decades, not just years, of experience in applying, specifying, designing, and fabricating automated valve systems for the power industry. Additional experience in other industry segments is a plus, but a working history and a proven, successful track record in power plant automation is mandatory. All production technicians should be factory trained with valid certification. Whether a 1/2” ball valve with simple electric actuator, or 48” valve gate with extensive controls, your valve automation partner needs to reliably and consistently ensure conformance to specifications.

Involvement

Your valve automation partner needs to remain involved in every step of the process - from specifying, quoting, fabrication, delivery, installation, and training. The best valve automators stand by the customer after the automated valve systems are shipped. They see the project through to completion, paying great attention to detail. They generally obsess over the smallest details. For instance, a critical area is actuator-to-valve adaption design and configuration and a good candidate will pay very close attention to that piece. Good valve automation partners create and provision high quality drawings and wiring diagrams. They carefully ensure all requested settings and configuration meets specification and is completed. Finally, they maniacally Q.C. the completed automated valve though in-depth cycle testing before shipping. A good valve automation partner truly understands that this investment in detail upfront, eliminates costly downstream errors and mistakes.

Documentation and Tagging

Your partner should provide very detailed documentation for each automated package. Documentation packages should be very detailed and include valve Cv, actuator sizing calculations, material selection criterion, ISA data-sheets, dimensional drawings, operational testing data, seat leak test data, packing leakage data, and switch setting verification. Your valve automation partner should standardly provide valve packages tagged with stainless steel stamped serial numbers that provide traceability back to original components, fabrication, and testing.

Facilities

Your valve automation partner should have in-house capabilities for lifting, moving, testing, and storing large valve assemblies. The facility needs adequate pneumatic and electrical service to power any system they build. The space and ability to move large valves with lifts, hoists, and jacks is important. Storage space for sub-assemblies and finished goods, high pressure leak testing stations, seat leak testing stations. In-house CAD systems and on-premise machine shops provide an environment for better quality control and communication. Close proximity between engineers, designers, and technicians supports efficient communication and full understanding of customer needs. An on-site training room, with all required electrical and pneumatic testing rigs should be available. Finally, large docking facilities and easy access to major highways minimizes transportation issues and lowers cost.

Training
valve automation training facility
Valve automation training facility
(courtesy of Mead O'Brien)
Your plant maintenance crews must have 100% familiarity with the operation, maintenance, and troubleshooting of your new valve systems. Your valve automation partner must have the capability to provide practical, and hands-on, training on all facets of valve automation. Programs must be customizable to customer needs and special situations.

By doing your due diligence, and thoroughly evaluating a prospective valve automation partner, you are establishing a framework of confidence and trust that minimizes risk and provides peace of mind that your critically important power plant valve systems will provide safe, efficient, and reliable performance for years to come.

Tuesday, February 28, 2017

Don’t Overlook the Value of Valve Automation Professionals on Your Next Valve Project

Sales and Engineering Professionals
Sales and Engineering Professionals are there to assist
and save you time and money.
Local distributors and representatives who sell industrial valves, actuators and controls also provide services and equipment that will save you time, money, and help you achieve a better outcome for the entire project.

Projects requiring engineered valve systems are best completed and accomplished through the proper selection and application of the valves, actuators, positioners, limit switches and other associated components. A great resource exists, ready to provide a high level of technical knowledge and assistance, that can be easily tapped to help you with your project - the valve automation sales professional.


Consider a few elements the valve automation professional brings to your project:

Product Knowledge: Valve automation professionals are current on product offerings, proper application technique, and product capabilities. They also posses  information on future product obsolescence and upcoming new designs. This type of information is not generally accessible to the public via the Internet.

Experience: As a project engineer, you may be treading on new ground regarding some aspects of your current valve system design assignment. There can be real benefit in connecting to an experienced and highly knowledgable source, with past exposure to your current challenges.

Access: Through a valve automation professional, you may be able to establish a connection to “behind the scenes” manufacturer contacts with essential information not publicly available. The rep knows people at the factories, a well as at other valve related companies, who can provide quick and accurate answers to your valve automation related questions.

Of course, any valve actuation or automation solution proposed are likely to be based upon the products sold by the representative. That is where considering and evaluating the benefits of any solution becomes part of achieving the best project outcome.

Develop a professional, mutually beneficial relationship with a local valve automation professional to make your design job go after, more efficiently, and more cost effective. Their success is tied to your success, and they are eager to help you.

For assistance with any industrial valve automation requirement, contact Mead O'Brien at (800) 892-2769 or visit http://www.meadobrien.com.

Thursday, February 4, 2016

The Rack and Pinion Style Pneumatic Valve Actuator

Automax 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.
internal of rack and pinion actuator

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.

rack and pinion
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.

actuated valve
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