Rugged Reliability: Kinetrol Actuators Thrive in Cement Plant Extremes

Introduction: In heavy industries like cement manufacturing, equipment is pushed to its limits by dust, heat, and constant vibration. At a large cement plant in Northern California, Kinetrol’s standard rotary pneumatic actuators and VLS (Valve Limit Switch) boxes have been operating in an extremely dusty, hot, high-vibration environment for years without a hitch. This case study highlights how these devices deliver exceptional durability and long-term reliability, remaining maintenance-free and operational despite the punishing conditions.

Harsh Conditions, No Downtime in a Cement Plant

Kinetrol’s rotary vane actuator (mounted under a cement hopper) and its VLS limit switch box endure layers of fine cement dust and constant equipment vibration while continuing to function flawlessly. In this Northern California cement plant, a gray film of cement powder coats every surface (as seen above), yet the Kinetrol actuator and limit switch keep performing with zero maintenance. Plant engineers cite these units as a rare “fit-and-forget” solution in an environment where most equipment struggles to survive.

Even with ambient temperatures soaring and heavy machinery churning nearby, the Kinetrol actuators have shown no signs of sticking or failure. “We’ve standardized on Kinetrol because it’s easy to own and works so much better than the rack-and-pinion style actuators we replaced,” says one maintenance supervisor at the plant​. In other words, the facility swapped out traditional actuators that kept breaking down, and the Kinetrol units have run smoothly ever since. This switch to Kinetrol has virtually eliminated actuator-related downtime on these cement discharge gates, despite the intense dust and vibration that used to cripple the previous devices.

Maintenance-Free Design Built for Extremes

What makes Kinetrol actuators and their companion limit switch boxes so resilient in such harsh conditions? The answer lies in robust engineering and a simplicity of design purpose-built for longevity. Each rotary vane actuator contains only a single moving part – an integral vane and shaft – which means there are no delicate gears or multiple linkages to wear out or misalign. Fewer moving parts translate directly to higher reliability and very low maintenance. In fact, Kinetrol’s one-moving-part design is inherently a sealed system that keeps contaminants out. Double opposed polyurethane lip seals on the shaft serve as self-adjusting wipers that prevent dust ingress and maintain a tight seal over time​. As the actuator cycles millions of times, these lip seals (backed by stainless steel spring expanders) continuously compensate for any wear, ensuring the internal components remain protected and pressurized air doesn’t leak​.

The VLS limit switch box shares the same rugged philosophy. Housed in a fully enclosed, die-cast metal casewith a corrosion-resistant epoxy coating, the VLS unit is sealed to IP67/NEMA 6 standards. This means that even the finest cement dust cannot penetrate the enclosure, and the internal switches and electronics remain clean and protected. The tight sealing also guards against moisture and grit, so the limit switches reliably indicate valve position without fouling or sticking. In practice, maintenance crews at the cement plant never need to open these switch boxes to clean them out – a stark contrast to lesser designs that might require frequent cleaning or gasket replacements in dusty service.

A close-up of a Kinetrol pneumatic actuator blanketed in cement dust at the plant. Despite the abrasive powder and ongoing vibration, the actuator’s performance remains unchanged. The unit’s one-piece vane mechanism and sealed construction prevent dust from clogging its operation, unlike many conventional actuators. The photo to the right illustrates the level of dust accumulation; yet, no special maintenance or adjustments have been needed to keep this actuator in service. This is because Kinetrol actuators are designed to be “fit and forget” – installed once and left to run with minimal oversight​. The company backs this confidence with a warranty of up to 4 million trouble-free cycles, and real-world tests have proven even greater endurance (field units have exceeded 30 million cycles without failure)​.

Crucially for the cement industry, Kinetrol’s design avoids the pitfalls that plague other actuator types in the same environment. Traditional rack-and-pinion pneumatic actuators, for example, rely on multiple moving parts and vented housings that let some air (and inevitably dust) in. Fine cement dust can block the small air vents in those units and then grind away at their internal gears and seals, eventually causing sticking or complete failure​. In contrast, a Kinetrol vane actuator is a nearly hermetic unit – it has practically no internal air cavities exposed to the outside, so abrasive dust can’t infiltrate and damage its mechanism​. Similarly, the vibration that shakes apart complex gear and piston actuators has little effect on Kinetrol’s simple vane/shaft assembly. There are no gear teeth to wear unevenly or external springs to fatigue; everything is compact and concentrically balanced. This robust construction is why even after years of constant use on a vibrating cement hopper, the actuators at this plant operate as smoothly as day one.

Real-World Proof of Long-Term Reliability

Kinetrol’s reputation for ruggedness isn’t based solely on one plant – it’s reinforced by countless applications across industries. For over 50 years, Kinetrol has been supplying “trouble-free” pneumatic rotary actuators to demanding sectors such as chemical processing, mining (mineral processing), oil and gas, power generation, and water treatment​. In each case, the story is similar: the actuators simply keep working year after year, often outlasting the equipment around them. A plant engineer from another facility quipped that the Kinetrol units “last so long, we sometimes forget they’re even there until we notice everything else has needed maintenance except them.”

Consider a case from the chemical industry: a southeastern US chemical plant installed a Kinetrol Model 187 actuator on a critical valve back in 1997​. That actuator has been cycling every two minutes, 24/7, for decades – tallying over 5 million cycles – and it is still in service today​. The original actuators (of a scotch-yoke design) that were on that valve had been failing due to seal leaks and jamming, but the Kinetrol replacement solved the reliability issues overnight​. It’s a testament to Kinetrol’s engineering quality that even after nearly thirty years in a harsh process (processing reactor off-gas), the vane actuator remains operational with no major repairs.

Another example comes from a steelworks handling abrasive slurries. There, a Kinetrol spring-return actuator was paired with a butterfly valve to replace an earlier actuator that kept failing due to slurry ingress and wear. After months in operation, the new Kinetrol-driven valve showed no signs of wear and dramatically reduced maintenance needs​. Such success stories have led many plants to adopt Kinetrol as their standard for critical valves and dampers. In the words of one plant manager, “We needed actuators that could survive literally anything – heat, dust, you name it. Kinetrol delivered, and we haven’t looked back.”

It’s not just marketing speak to call Kinetrol actuators “simply the best” in quarter-turn actuation – the industry has watched them perform where others fail​v. With an environmentally rugged design and outstanding cycle life, they have earned a loyal following. Even competitors’ engineers acknowledge the long service life and dependability of the Kinetrol units. As one distributor commented, “Kinetrol’s are great actuators and we love supplying them!”​. This kind of praise underscores the broad confidence in Kinetrol’s ruggedness and engineering quality.

Conclusion: Engineering You Can Rely On

The cement plant in Northern California is a powerful demonstration of Kinetrol’s durability. In an environment that combines every possible stress factor – abrasive dust, high heat, continuous vibration, and round-the-clock operation – the Kinetrol standard pneumatic actuators and VLS limit switch boxes continue to excel with truly maintenance-free performance. Months and years pass with virtually no attention needed from the maintenance team, freeing them to focus on other equipment. The actuators stroke open and closed reliably, and the limit switches faithfully report positions to the control system without fail.

For plant operators and engineers, this level of reliability translates into peace of mind and lower lifetime costs. There are no surprise shutdowns due to actuator failure, no weekly lubrication rounds, and no stockpile of replacement parts needed. Kinetrol’s “fit and forget” philosophy is more than a catchphrase – it’s a reality backed by decades of field experience and a design that prioritizes simplicity, strength, and seal integrity. When other actuators seize up or wear out under extreme conditions, Kinetrol units keep on turning. This exceptional longevity and ruggedness make Kinetrol actuators and VLS limit switches a smart choice for any operation where downtime is not an option and equipment must survive the harshest conditions. In short, if you need an actuator solution that laughs in the face of cement dust and heat, Kinetrol has proven time and again that it can deliver exactly that.

For professional industrial audiences looking for long-term reliability, the message is clear – when the going gets tough, Kinetrol actuators keep going, year after year, cycle after cycle, without maintenance and without fail.

Kinetrol USA
https://kinetrolusa.com
972-447-9443

Redefining Reliability: Kinetrol and the Makings of an Exceptional Brand

A successful brand shapes how people perceive a company, its products, and the value it promises to deliver. It goes beyond a simple logo or tagline and resonates through every interaction, from customer service calls to product performance in the field. A company with a strong brand influences market expectations and gains credibility as a reliable choice. Customers want products that live up to a legacy of excellence, and they place their trust in names they associate with cutting-edge innovation, superior quality, and long-term dependability.

Building this brand recognition level involves more than glossy brochures and a clever tagline. It starts with a clear identity and a promise that resonates with the marketplace. Leadership teams articulate a distinct message and then back it up with tangible, measurable actions. They invest in research and development, take pride in rigorous testing, and never compromise on craftsmanship. Over time, word spreads that this brand meets or exceeds expectations. Early adopters become brand ambassadors, and new buyers approach with confidence. Once a brand captures this reputation for high performance and durability, it enjoys a place at the forefront of its industry.

Top-tier companies often evolve into something akin to a luxury brand. Although that phrase usually refers to high-end fashion or premium consumer goods, it also triggers the notion that a higher price conveys top-quality materials and uncompromising design. People pay more when they trust that every extra penny leads to advanced features and a longer lifespan. The notion of industrial equipment as a luxury brand may initially feel unusual, but a similar dynamic applies. Specialists in oil and gas, chemical processing, and power generation prefer components they know will stand up to demanding applications. They invest in products that deliver years of reliable service, reduce downtime, and support profitability. Those decisions reflect the same mindset that drives buyers toward a luxury automobile or a premium technology.

Kinetrol actuators epitomize this elevated status. They stand out in a crowded marketplace because of their unwavering commitment to reliability, craftsmanship, and performance. Engineers rely on Kinetrol actuators to operate in harsh and corrosive environments, and maintenance professionals value their straightforward design that keeps downtime to a minimum. Kinetrol invests heavily in advanced manufacturing processes and quality assurance, which creates a level of trust that few competitors match. Buyers never have to question whether an actuator will function as intended when every minute counts.

This longstanding emphasis on excellence places Kinetrol in the same league as other iconic names in industrial technology. Fisher control valves, Rosemount process instrumentation, and Swagelok fittings have each built their legacy through a similar approach. They commit to thorough product testing, pay attention to every detail, and encourage direct feedback from end users to drive ongoing improvements. Their reputations reward them with brand equity that stretches across the globe. Kinetrol stands beside these established leaders because it shares the same philosophy: promise superior performance, deliver consistently, and let the marketplace decide.

The word “brand” often evokes sleek advertisements or the race to capture social media buzz, but at its core, a brand represents the essence of a company’s character. It communicates a powerful promise that only holds meaning when a business has the substance to back it up. Kinetrol’s consistent innovation, quality, and customer satisfaction record demonstrates how a company can become synonymous with top-tier products. Industrial buyers who see Kinetrol on a specification sheet understand they are selecting a product that fits the best in class alongside other legendary names. The result is a brand that stands for more than a product line—it signifies trust, dedication, and unwavering leadership in every aspect of industrial actuation.

Kinetrol USA
https://kinetrolusa.com
972-447-9443

Kinetrol Rotary Vane Actuators. Simply the Best.

Kinetrol rotary vane actuators have a well earned, and long established, reputation for  performing where other pneumatic actuators fail. With outstanding cycle life, smooth and precise operation, and an environmentally rugged design, Kinetrol actuators are "simply the best" quarter-turn valve and damper actuator on the market today. Period.

For more information, contact Kinetrol USA. Call them at 972-447-9443 or visit their website at https://kinetrolusa.com.

The Top Five Reasons Why Kinetrol is a Better Choice Than Rack and Pinion Actuators

1. Rotary vane actuators do not convert linear motion to rotary motion, unlike rack and pinion actuators. 

No additional gearing is required and no side loading is transferred to the actuator housing.

2. Vane actuator lip seals are the key for long life. 

The double opposing lip seal design, with stainless steel expanders, provides unmatched service life by using air pressure to improve the actuators seal-to-enclosure contact, and provide a “self cleaning” effect on the epoxy or PTFE internal finish.

3. The elimination of pressure bearing o-ring shaft seals. 

Rack and pinion actuators require shaft sealing o-rings that are exposed to the full supply air pressure used to operate the actuator. These o-rings wear, causing leaks, a drop in efficiency, and wasted energy through air consumption. Vane actuators' double opposing lip seals isolate the supply air pressure from the actuator shaft, requiring only a low friction bearing on the shaft.

4. Rotary vane actuators provide superior modulating accuracy. 

Because of the integral vane and shaft (machine from a single casting), lost motion or hysteresis is reduced dramatically which intern provides much tighter modulation and control. The vane actuators inherent low friction also reduces hunting and sticking.

5. Rotary vane actuator spring return units are designed to be virtually indestructible. 

Using low stress, clock springs reduces spring tension loss and metal fatigue. The housing for vane a actuator springs are sealed from the atmosphere, preventing corrosion of internal parts. Most importantly, these type of spring units provide the lowest torque loss which enables the section of smaller (less expensive) actuators.

Kinetrol USA
https://kinetrolusa.com
972-447-9443

The Most Reliable 1/4 Turn Pneumatic Actuator on the Market Today. Period.

With millions of actuators performing reliably around the world, the Kinetrol vane actuator's outstanding cycle life, smooth and precise movement, and environmentally rugged design makes it the best choice for all of your valve actuation needs.

Pneumatic Valve and Damper Actuators: A Design Comparison

Industrial valves, dampers and louvers are operated either electrically or pneumatically. This post compares the three major categories of  pneumatic valve actuators, namely:

1. Rotary vane
2. Scotch-yoke
3. Rack & pinion

All three categories provide the same basic function - converting air pressure to rotational movement intended to open, close, or position a quarter-turn valve (ball, plug, butterfly), louver or damper.

All three can be configured in either direct acting or spring return versions. Direct acting actuators use the air supply to move the actuator in both directions (open and close). Spring return actuators, as the name implies, uses springs to move the actuator back to its "resting" state. Converting from direct acting to spring return is done through simple modifications, typically just adding an external spring module, or removing the end caps from rack and pinion actuators and installing several coil springs.

Rotary Vane Actuator

Rotary Vane Actuators

Vane actuators generally provide the most space savings when comparing size-to-torque with rack and pinion and scotch yoke. They have an outstanding reputation for long life because then contain only one moving part, as opposed to rack and pinion and scotch yoke actuators that have many. They tend to withstand dirty and corrosive atmospheres better than rack and pinion and scotch yoke actuators. Vane actuators also use externally mounted, helically wound "clock springs" for their spring return mechanism.

Scotch Yoke

Scotch-yoke actuators use a pneumatic piston mechanism to transfer movement to a linear push rod, that in turn engages a pivoting lever arm to provide rotation. They come in a wide variety of sizes, but are very often used on larger valves because they are capable of producing very high torque output. Spring return units have a large return spring module mounted on the opposite end of the piston mechanism working directly against the pressurized cylinder.

Rack and Pinion

A rack & pinion pneumatic actuator uses opposing pistons with integral gears to engage a pinion gear shaft to produce rotation. Rack & pinion actuators (sometimes referred to as a lunch box because of their shape) tend to be more compact than scotch yoke, have standardized mounting patterns, and produce output torques suitable for small to medium sized valves. They almost always include standard bolting and coupling patterns to directly attach a valve, solenoid, limit switch or positioner. Rack and pinion actuators use several smaller coil springs mounted internally and provide the torque to return the valve to its starting position.

The practical difference between these three types of pneumatic actuators comes down to size, power, torque curve and ease of adding peripherals. For the best selection of valve actuator for any quarter turn valve application, you should seek the advice of a qualified valve automation specialist. By doing so your valve actuation package will be optimized for safety, longevity, and performance.

Scotch yoke mechanism image courtesy of Wikipedia.
Rack and pinion mechanism image courtesy of Wikipedia.

Kinetrol Actuator Feature Video

Here's a new Kinetrol vane actuator feature video. Please take a minute to watch. Hope you enjoy.

Vane, Shaft and Seal Design: The Critical Difference in Pneumatic Rotary Valve Actuators

Click images for larger view.

The vane actuator produces rotary motion through the application of air pressure to a "vane' attached directly to an output shaft.

There are several manufacturers of pneumatic, rotary vane valve actuators on the market. Outwardly they appear similar. Internally, there's a world of difference in their design and their performance.

In higher quality vane actuators, the vane and shaft are machined from a single piece of steel. Casting and machining adds cost, but also adds performance. Lower quality actuators save cost by using a 2-piece vane/shaft combination. These are more likely to be affected by backlash or lost motion.  In other words, a one-piece shaft and vane assembly transfers 100 percent of the vane movement directly to the shaft. Two-piece designs may lose movement over time, reducing control and accuracy.

Higher quality pneumatic vane actuators incorporate a pair of “lip seals” around the vane. The durable and resilient polyurethane seals provide two key benefits; eliminating the need for o-rings; and eliminating shaft seals. Dual, opposing lip seals are located each side of the vane. They isolate the vane and shaft from the air supply and create an area from the shaft through the center of the vane that remains unpressurized, eliminating the need for pressure seals around the top and bottom of the shaft.

Some lower quality vane actuator designs use an o-ring around the entire vane, exposing the o-rings to mechanical stress and rolling. Higher quality actuators back their polyurethane lip seals with stainless steel expanders that maintain the integrity of the seal to the actuator housing.

The heart of the pneumatic vane actuator is simple design. Manufacturers often promote the concept of "a single moving part", referring to the vane/shaft/seal assembly. But despite this claim, all pneumatic vane actuators are not the same. You owe it to yourself and your organization to "look under the hood".  See what level of engineering and quality you're really getting.

How Kinetrol Pneumatic Rotary Vane Actuators Work

Kinetrol pneumatic rotary vane actuators use a one piece vane and shaft produce rotary torque on the shaft output drive. The vane is assembled inside a 2-piece clam-shell enclosure. The presence of the vane creates two air chambers. By pressurizing and venting opposing chambers, the resulting pressure differential across the vane provides torque to the shaft. Torque output of the rotary vane actuator remains constant throughout the full rotation of the shaft.

http://www.kinetrolusa.com | 972-447-9443

9 Kinetrol Features Providing Unmatched Actuator Performance

1. Long life epoxy or PTFE internal finish
2. Easy stop adjustment at each end of stroke for accurate seating
3. Corrosion resistant zinc (non-incendive) or aluminium alloy case
4. Integral vane/shaft casting - only one moving part
5. Manual override square and position indicator
6. Stainless steel expanders ensure long term lipseal / case contact
7. Double opposed, Polyurethane, lip seals for effective sealing and long maintenance free life
8. Space filling/energy absorbent sideplates (polymer or metal)
9. Durable epoxy stove external enamel finish

Kinetrol USA - http://www.kinetrolusa.com | 972-447-9443

Dampers and Louvers Used in Power Plants, Refineries, Boilers, and Furnaces

Parallel damper with electric actuator.

A damper (otherwise known as a louvre) is a multi-element flow control device generally used to throttle large flows of air at low pressure. Dampers find common application in furnace and boiler draft control, and in HVAC (Heating, Ventilation, and Air Conditioning) systems.

Radial damper.

Common damper designs include parallel and radial. Parallel-vane dampers resemble a Venetian blind, with multiple rectangular vanes synchronously rotated to throttle flow through a rectangular opening. A photograph of a parallel-vane damper is shown above, part of an induced-draft (suction) air fan system on a separator at a cement plant. The vanes are not visible in this photograph because they reside inside the metal air duct, but the electric actuator mechanism and linkages connecting seven vane shafts together are visible.

Pneumatic vane actuator damper drive.

Radial-vane dampers use multiple vanes arranged like petals of a flower to throttle flow through a circular opening. A photograph of a radial-vane damper is shown here (note the levers and linkages on the periphery of the tube, synchronizing the motions of the eight vanes so they rotate at the same angle).

Dampers are opened and closed by electric or pneumatic drives. In recent years, the pneumatic vane actuator  has earned an reputation for modulating dampers. Used in critical applications commonly found in power plants, refineries, boilers, and furnaces, these unique damper drives provide precise combustion gas management, are proven to increase boiler efficiency, lower fuel consumption, reduce emissions, and reduce maintenance cost.


Parts of this post are reprinted from Lessons In Industrial Instrumentation by Tony R. Kuphaldt – under the terms and conditions of the Creative Commons Attribution 4.0 International Public License.

Shark-Tested Rotary Vane Actuators

For those of you who live under a rock, Shark Week  is a week long TV programming block put on by the Discovery Channel. Usually occurring in mid-late July or early August, it features entirely shark-related programming. Everything from great educational documentaries to completely ridiculous events such as Micheal Phelps racing a Great White.

So what does a blog about rotary vane actuators have to do with Shark Week? The answer lies with the good people at MythBusters.

Out to prove (or disprove) the long-standing theory that punching a shark in the nose will scare it away, host Jamie Hyneman had to design a robotic shark punching machine that would deliver a powerful punch, similar to one that a real human being would deliver.

As they have in a past MythBuster episode, the MythBusters team turned to Kinetrol for the crucial piece of equipment - the Kinetrol pneumatic rotary vane actuator.

The result was an underwater "Rock 'em Sock 'em Robot" machine with two arms, each powered by a Kinetrol Model 07 Actuator.

How Kinetrol Pneumatic Rotary Vane Actuators Work

Kinetrol pneumatic rotary vane actuators use a one piece vane and shaft produce rotary torque on the shaft output drive. The vane is assembled inside a 2-piece clam-shell enclosure. The presence of the vane creates two air chambers. By pressurizing and venting opposing chambers, the resulting pressure differential across the vane provides torque to the shaft. Torque output of the rotary vane actuator remains constant throughout the full rotation of the shaft.

Industrial Dampers and Drives

Round dampers with
pneumatic vane type drives.

By definition, a damper is a device used to control pressure, flow, or flow direction in an air or gas system. Different types of dampers can be used, depending on specific functional requirements. Table 5.7 below lists the types of dampers and their functions, and Table 5.8 lists the damper configurations. Selection of the proper damper type and blade configuration is important to achieve the required damper performance. The type and configuration of damper can significantly impact pressure drop, leakage rates, and controllability.

Click table for larger view.

Click table for larger view.

Pneumatic vane damper drive.

A very important part of damper design is determination of damper torque and sizing and selection of damper actuator for the maximum torque. Actuator torque should be selected for a minimum of 1.5 times the damper maximum torque to provide margin and allow for degradation over the life of the damper. Actuators should be evaluated for damper blade movement in both directions, at the beginning of blade movement, and while stroking blades through the full cycle of movement.

Damper operators can be one of three types: pneumatic, electric, or electro-hydraulic, as described below.

1. Pneumatic. These damper operators are used whenever controls rely primarily on compressed air (pneumatic) for moving operators or transmitting control signals.
2. Electric. These damper operators are used whenever controls rely primarily on low voltage electric circuits to transmit control signals.
3. Electrohydraulic. These damper operators are the same as the electric type described above, except they have the ability to modulate. They use an electric control signal to position a hydraulic system that, in turn, positions the damper.

Electrically operated damper drives have historically been favored, but the shift to retro-fit electric drives with pneumatic damper drives has been significant in the last two decades. When pneumatic vane actuators were first introduced for damper drive service, their virtues were quickly discovered. Their inherent design and operating advantages apply perfectly for precise damper control. These design and operating advantages are:

• Damper drives on round dampers.
• Precise, smooth signal to movement response.
• 100 percent duty cycle.
• Continuous modulating service.
• No overheating.
• High speed/high-torque.
• Fast full stroke open/close.
• Very easily serviced.
• Excels in harsh, high-temperature operating environments.
• Effectively zero air consumption in resting state.

For more information on any damper drive application, contact Kinetrol USA at 972-447-9443 or visit http://www.kinetrolusa.com.

Why Vane Actuators Are Better - We'll Make This Easy

With millions of actuators performing reliably around the world, the Kinetrol vane actuators' outstanding cycle life, smooth and precise movement, and environmentally rugged design makes it the best choice for all of your valve actuation needs.

The rotary vane actuator design is based upon a single moving part which eliminates additional parts required to convert linear motion to rotary motion. This simple and innovative design provides a highly accurate and extremely reliable actuator for operating valves, drives and dampers, and is perfectly suited for the most demanding process control control applications.

Lower Total-Cost-of-Ownership in Poor Process Environments with Pneumatic Vane Actuators

Design advantages for use in poor process conditions (click for larger view).

Clean, dry instrument air is critical for pneumatic instruments and actuators to work properly. In remote, dirty process control environments, like refineries, chemical plants, power plants, water treatment facilities, pulp & paper mills, or mining facilities, providing clean instrument air is challenging,  costly and problematic.  Along with poor instrument air, the ambient air in these areas is generally filled with dust and contaminants. Process equipment must be engineered to withstand these conditions, and devices with low tolerance to dust, dirt, condensate, and poor ambient air quality (such as rack and pinion actuators) are to be avoided. Devices in these areas are costly to maintain as shut-downs and repairs are very expensive.

For the operation of pneumatically controlled valves, and as a better alternative to rack and pinion actuators, Kinetrol rotary vane actuators are an excellent choice. Their simple design, with one moving part, and an elegantly engineered vane, inherently protects the actuator from bad instrument air. Kinetrol's use of double opposed polyurethane lip seals, backed by stainless steel expanders, ensure long-term lip seal contact and effective sealing for years of maintenance free life. The vane, lip seals, and expanders actually provide a self-cleaning, or wiping, mechanism for any moisture, dirt or dust entering the interior of the actuator. In effect, the vane actuator's design "sweeps away" the debris that will cause other actuators to fail.

A considerable cost savings can be calculated given the trouble-free performance Kinetrol vane actuators provide. Assuming both a Kinetrol and standard rack and pinion actuator cost approximately the same, and that the life of a typical rack and pinion actuator in these environments is approximately 1 year, you can easily see the savings. By factoring in the replacement cost for an new actuator, and the cost of labor to install, you’ll find a standard rack and pinion is at least 2.5x the cost of Kinetrol over a 2 year period.

Kinetrol actuators have a well-earned reputation for operating trouble-free for years in the most difficult environments. Considering their years of maintenance-free service, it’s easy to understand the significantly lower total-cost-of-ownership they deliver.

For more information, visit Kinetrol USA at http://www.kinetrolusa.com or call 972-447-9443.

Avoid Fretting and Backlash with Rotary Vane Actuators

Fretting and backlash
shorten actuator life and
negatively affects controllability
over time.

The American Society for Metals Handbook on Fatigue and Fracture defines fretting as: "A special wear process that occurs at the contact area between two materials under load and subject to minute relative motion by vibration or some other force."

In pneumatic valve actuators, fretting wear is caused by the repeated cyclical rubbing between gears in scotch yoke or rack and pinion actuators. Over a period of time, fretting will remove material from one or both surfaces. This extra material, or debris, is usually harder than its source material due to work hardening and oxidation. The resulting debris becomes an even more effective abrasive, increasing the rate of mechanical wear and continued fretting.

Backlash happens when gears change direction. It is caused by the gap between the trailing face of the driving tooth and the leading face of the tooth behind it. The gap must be closed before force can be transferred in the new direction, hence the phenomena of backlash. This is also sometimes referred to as "slop".

Both fretting and backlash significantly effect the service life of an pneumatic valve or damper actuator. Both are also detrimental to controllability when actuators are used to accurately manage the percent open status of a valve or damper.

Internal view of a rotary vane actuators.
Notice the vane is constructed from
a single piece of stock and
contains no gears.

An alternative actuator design is the rotary vane design that uses a single piece of machined steel for both the vane body and drive shafts. With this design, the shaft and vane are not affected by backlash, friction or wear. Vane actuator's incorporate a design with only a single moving part that provides very repeatable, smooth movement that will not decay over time.

For more information, visit http://www.KinetrolUSA.com or call 972-447-9443.

Rotary Vane Valve Actuators

Rotary vane actuator

A rotary vane actuator is simply a part of an automated valve assembly: its role is to change the position of the valve, converting the motive force of fluid pressure into torque and applying it to a valve stem.

Quarter turn valves are widely used in industrial process automation. Their application is primarily for operations requiring fully open or fully closed valve trim positions, although some do provide modulating service. A rotation of the valve stem through a 90 degree arc will reposition quarter turn valve trim between open and closed positions. A rotary vane actuator is well suited for driving this type of valve, with its own 90 degree arc of movement.

A rotary vane actuator operates quarter turn valves, dampers and louvers. A pressure tight housing contains a movable vane which is sealed to the sides of the pressure chamber by means of a low friction gasket. Inlets into the chamber on opposing sides of the vane allow a controller to produce a pressure differential across the vane. The vane will move, in response to the pressure differential, in either direction. A shaft is connected to the vane and the vane acts like a lever to rotate the shaft as the vane is moved by fluid pressure. The torque produced by the actuator assembly is primarily dependent upon the applied fluid pressure.

Hydraulic rotary vane actuators have the ability to handle large amounts of fluid and dynamic motions, exhibiting also qualities of durability and compactness. Pneumatic vane actuators use plant air pressure as the motive force. Both types generally have few moving parts and require little regular maintenance. A variety of typical automation accessories and options are available to customize a unit for a particular application.