The Flowserve Logix 3800 Digital Valve Positioner

The Logix 3800 positioner features powerful diagnostics that identify field problems and expedite corrective actions to ensure reduced return-to-operation times.

Compatible with linear and rotary valves and actuators, the robust design of the Logix 3800 delivers high reliability in tough environments, reduces inventory costs and contributes to a lower total cost of ownership, and installs with an innovative, one-button quick calibration feature.

Partial List of Features:

• Rugged, certified SIL 3 capable modular design delivers maximum reliability in the toughest environments. 
• Installation and operation ease from innovative quick calibration feature to simplify commissioning. 
• Broad application versatility with industry-leading communication technologies, including analog, HART, Foundation Fieldbus, 4-20 or discrete I/O signals.
• Intrinsically safe, non-incendive and explosion-proof design from -52°C to 185°C (-62°F to 365°F) ensures safe, reliable operation in hazardous conditions for increased plant and personnel safety.
• Compatible with a variety of valve and actuation configurations including: rotary or linear valves; double- or single-acting; air- to-open or air-to-close.

https://cti-ct.com
925-208-4250

Why Do We Debate Air vs. Electric Powered Valve Actuators?

Industrial Process Control Valve
Courtesy Rotork

Which is better, air or electric? We're talking about valve actuators here. Just for perspective on how original this article might turn out to be, I commanded my friendly Google search engine to look for "air vs. electric actuators". Google always finds something, no matter what you ask, giving the humble user an impression that the big "G" has all the answers....and they truly may. Don't misunderstand me. I am a big Google fan. Someday I might even pay for something that they provide me. Anyway, I was humbled by the avalanche of search returns on my the subject, 17,200,000 articles. That's a large number, even for a Google search. Many of the articles related to industrial machinery automation, not valves. Changing my search to "electric vs pneumatic valve actuator" shaved the returns down to 236K, a more manageable volume.
Dutifully reading the highest ranked articles and following threads in forums, I started to wonder why, like figurative gladiators, we pit these two valve actuator motive power sources against one another. There is not a single winner in this case. One is not universally better, more advantageous, than the other. Both methodologies have instances where they can be used to best advantage. A good recommendation is to not be too influenced by the past, by what your own industrial process control experience may have been. The manufacturers of these products are continuously modifying designs and releasing products with newer technologies and better performance that may eliminate some shortcomings of the past.

Your best course of action is to consider the following:

• What is the expected useful life of the process? Short term, long term, permanent?
• Will existing air supply and piping system accommodate the anticipated additional pneumatic valve load, if that type actuator seems otherwise advantageous?
• Are there sufficient maintenance and technical resources in place to keep either system in top operating condition and successfully deal with operational and repair issues that will arise? Does the current maintenance staff have sufficient knowledge and training to perform needed tasks?
• Are there rated hazardous zones where valves will be located?
• What needs to happen to valve position if motive power (air pressure or electricity) fails?
• What valve positioning requirements are associated with proper control of the process?
• What interfaces with any existing control systems, if any, need to be accomplished?

Carefully consider these points, add several of you own. Consult with knowledgeable sales engineers that specialize in valve automation. Combine experience and knowledge from a number of sources and a good solution will materialize. 

Valve Actuator IQ Suffering? This Information Library Can Help.

IQ Series Electric Valve Actuator
Courtesy Rotork

For any component of your industrial process, there is a manufacturer that knows all about how to properly and safely apply, service, maintain, and repair it. The devices we employ to measure and control industrial processes and machines grow increasingly numerous and complex. While this provides operators with greater amounts of useful information, leading to safer and more efficient process operation, the burden on engineers and technicians tasked with coaxing maximum uptime and efficiency from the process grows. Never before has continuing education, even relearning of basic knowledge, been so important. One manufacturer has invested in helping customers and other industrial process control stakeholders keep their operation and maintenance knowledge current.

Rotork, a global manufacturer of industrial valve actuators, maintains extensive online information sources that are accessible to registered users. The instructional and educational assets include online course applications, videos, and other materials to familiarize the user with various aspects of Rotork actuators, their proper application, operation, and maintenance. The large library of "How to" videos provides clear instruction on the safe operation and application of the Rotork actuators, along with step-by-step instruction on how to perform the range of operations involved with obtaining the greatest benefit of ownership. Process engineers, operators, and technicians will all benefit from the assets, enabling them to interface with the products with the confidence that comes from knowledge.

Contact your Rotork distributor for instructions and assistance in gaining free access to the educational tools.

Intelligent Valve Control for Part-Turn Valves

ICT 3rd Generation

The introduction of this new electric valve actuator brings the advanced functionality and asset management capabilities of intelligent technology to the direct-drive operation of part-turn valves.

Valve maintenance requirements can be identified and anticipated, eliminating unplanned interruptions to the process or over-cautious planned maintenance outages. The actuator's powerful datalogger provides comprehensive data capture for planned maintenance and troubleshooting. Data includes valve torque profiles, operational start profiles, vibration and temperature trend logs and an event log. Specific asset management information includes running time, average torque and number of starts. Service or maintenance alarms are selectable from configurable menus including open and close torque levels, total starts and vibration levels.

IQT 3rd Generation Electric Part-Turn Aactuator from CTi Controltech

For more information contact:

CTi Controltech
22 Beta Ct.
San Ramon, CA 94583
Phone: 925-208-4250
Fax: 925-208-4251
Email: contactus@cti-ct.com

www.cti-ct.com

ROTORK IQ Electric Actuator Overview

Here is a quick overview of one of the most popular, and universally specified, electric actuators - the ROTORK IQ Series.

The IQ electric actuator features include ROTORK's unique double-sealed enclosure, ‘non-intrusive' infra-red commissioning, data-logging, predictive maintenance, Bluetooth® communications interface and absolute encoder.

The IQ functionality and reliability is available for valves of virtually every size and description, including multi-turn (rotary), quarter-turn, isolating and modulating, with watertight and hazardous area approvals to all internationally recognized standards.

Torque and Limit Switch Considerations When Applying Electric Valve Acuators

When selecting an electric actuator for industrial valves, an understanding of the valve torque requirements, both at start of travel, and end of travel, is critical for proper operation and optimal service life. Additionally, the ability to accurately set, or limit, disk travel is required.

Many of today's industrial electric valve actuators provide easy setting or programming of travel and torque sensing.

This short video provides a brief visual understanding of the reasons why valve torque and travel limits are important.

An Industrial Electric Actuator Designed to Keep the Water and Dust Out

The Rotork IQ3 electric actuator includes a double o-ring seal to keep the internal parts sealed away from water and dust should the electrical conduit seals fail.

The Rotork IQ3 also includes these advanced features:

• New intuitive user interface
• Advanced dual stacked display with configurable datalogger functionality
• Toughened glass screen plus optional environmental shield
• Setting tool with secured Bluetooth® connection
• High reliability, solid-state controls
• Reduced internal wiring and connections
• Simplified torque sensor
• Simple and robust absolute position sensor with high reliability and accuracy
• New thrust base design
• Separable gearbox/thrust base across the range
• Advanced real-time status reporting

Watch this video to see the how the IQ3 double o-ring seal keeps out water and dust.

Control Valves in Industrial Control Systems

Cashco rotary
control valve

One of the most ubiquitous final control elements in industrial control systems is the control valve. A control valve attempts to regulate flow through a pipe, reacting to a signal from some type of controlling device or balancing circuit, such as a simple on/off sensor, PID loop controller, or a programmable logic device (PLC). Control valves designs are available for simple (on/off) control of flow, or for more sophisticated applications that are intended to regulate flow between a fully opened valve and a fully closed valve.

Class 1500 Ball Valve and Actuator Retrofit

Class 1500, metal seated ball valve
with Rotork pneumatic spring return
actuator and hydraulic override.

CTi Controltech's broad engineering experience was recently challenged with the retrofit of a worn out globe valve and hydraulic actuator, to a new high pressure (Class 1500), metal seated ball valve and actuator package used on 10,000 lb. per hour steam system. 

The customer is a large US Navy contractor located in Northern California. The application is the main steam stop valve on the contractor's steam boilers that provide steam for their turbine testing facility. The contractor's facility simulates conditions on US Navy ships so that turbines and related equipment can be properly tested. 

One of the biggest challenges was to replace the valve and actuator in a very tight compartment. Space was extremely limited.

CTi, along with actuator manufacturer Rotork, came up with the right package to meet the very demanding operating conditions, as well as the working with the small space available.

The job involved the removal of the old globe valve and hydraulic actuator, and then having the new ball valve and pneumatic actuator package lowered through a hole cut in the facilities' roof. A very large crane, with a 200 foot boom, was used for the placement.

The new metal seated, Class 1500 ball valve was outfitted with a Rotork GP200 pneumatic, spring return actuator that included an hydraulic manual override.

The new valve and actuator package works exceptionally well, and the customer is very pleased CTi engineers came up with a solution that fit in to the existing space.

Rack and Pinion Pneumatic Actuator Basics

A rack and pinion gear.
(Courtesy of  Wikipedia)

Rack & Pinion actuators are designed for operating quarter-turn valves such as butterfly, plug, and ball valves or for actuating 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”.

In a pneumatic actuator, pistons are attached to the rack. As air or spring power is applied the to piston, the rack is “pushed” inward or “pulled” outward. This dual direction linear movement is transferred to the rotary pinion gear providing bi-directional rotation.