Tough Actuator Service on Paper Plant Green Liquor Line

Pulp and Paper Plant
Pulp and Paper Plant
It's said the only thing a pulp and paper plant doesn't reuse is the "shade the building casts". The processes used in the production of pulp and paper are very efficient when you consider the reuse of energy and by-products. The efficiency comes at a cost though - through very hostile atmospheres and demanding operating conditions for process equipment.

For example, the "kraft process" (also known as the sulfate process) is the method to convert wood chips into pulp and then to cellulose fibers. This is done by mixing the wood chips with sodium hydroxide and sodium sulphate, soaking, cooking and processing.

Here's a very basic explanation of the kraft process. Wood chips are soaked and processed in sodium hydroxide and sodium sulphate mixture known as "white liquor".  After the wood chips are impregnated with white liquor, they are then cooked in digesters to break the wood down into cellulose. The solid pulp is then separated and the remaining fluid is referred to as "black liquor". Black liquor is further processed to remove solids and chemicals which are to be re-used in the pulping process. One of the final by-products is "green liquor" which contains sodium carbonate and sodium sulfide and is then reacted with lime to regenerate more white liquor.

All of these steps expose process equipment, piping, and valves to very tough environments. Kinetrol actuators are preferred in these situations because they don't allow corrosive atmospheres to penetrate the actuator or springs, their long cycle life,  and their epoxy stove enamel finish.

Below is a picture of a Kinetrol model 14 double acting actuator on a 8” full-port ball valve on a green liquor line. The valve cycles 2 times per day to direct green liquor flow and weak wash (weak white liquor) alternatively from one pipe to another in order to prevent solids build up in the pipelines.

Kinetrol Model 14 in Green Liquor Line




Don't Get Racked Up ... Use Kinetrol Vane Actuators

Little video "commercial" about the virtue of Kinetrol Vane actuators over pneumatic rack and pinions actuators ...

Kinetrol vane actuators provide:
  • Single moving part - Simplest and most reliable mechanism for quarter-turn rotary actuation.
  • Close couple control modules - Fail-safe spring returns, limit switches, positioners and solenoid valves all close couple to the actuators.
  • No cranks or gearing - No power loss or backlash - allows accurate positioning.
  • Durable corrosion resistant finish
  • Long maintenance-free life - Up to 4 million operations guaranteed.
  • Compact - space saving - efficient: Best torque/size package available, fast operating speeds, best air consumption, proven design.

The Virtues of the Pneumatic Vane Actuator Damper Drive

pneumatic damper drives
Pneumatic damper drives
Pneumatic damper drives significantly improve the reliability, precision, and efficiency of industrial boilers and furnaces. Accurate control of combustion air and flue gas provide many cost savings benefits to plant operators. A pneumatic damper drive’s precision and rapid response greatly improve fuel efficiency, reduce emissions, lower fuel consumption, and provide better boiler draft control.

Recent “Boiler MACT” (Boiler Maximum Achievable Control Technology) regulations require regular maintenance to optimize boiler performance. Air-to-fuel mixing and CO emissions are two areas where fine tuning and precise control yields dramatic improvement in burn efficiency. Old electric drives do not provide the precision, speed or torque needed for accurate control, so a retrofitting program that replaces electric drives with pneumatic units is an easy way to improve efficiency and gain better performance.

In the application outlined below, several dual-arm damper drives, using Kinetrol Model 18 actuators, were specified to replace aging Bailey electric damper drives in a power plant in the southwest USA. These specific drives are used to control the desuperheater and reheater temperature at a gas fired plant. Not only was there a need for optimized performance for better fuel consumption and lower emissions, but the customer was also very concerned about reliability. The plant needed to know the new Kinetrol-based damper drives were immediately available, and ready for drop-in replacement as the Bailey drives failed. This was easily managed by designing pedestals and frames that matched the bolting patterns and envelope size of the existing Bailey units. The Kinetrol drives were designed to match the legacy footprint exactly, have the drive shaft and drive lever in the exact position, and provide a drive shaft and lever with the same dimensions as the Bailey drive.

The result is a high duty cycle, highly precise, long-life, fast acting, responsive, easily maintained, and easily automated damper drive.

The Principles of Rotary Actuators

rotary actuator
Variation of the rotary actuator.
(Kinetrol pneumatic vane actuator.)
A rotary actuator is an output device for a fluid power system that delivers an oscillating motion over a limited range in less than one full revolution of the circle.

A true rotary actuator produces work by direct action of fluid pressure against internal vanes. Work is defined as a force applied over a distance. Rotary actuators produce a special type of rotational work called torque.

Torque occurs when a force acts on a radius. Since rotary actuators operate at low speed with high torque, torque output rather than the horsepower is used for the rating and identification purposes. Speed is a secondary consideration when choosing a rotary actuator for a particular application.

The typical units of measurement for torque are foot pounds (lb·ft). For example, if a rotary actuator with an arm length or radius of two feet were used to lift the two hundred-pound weight, then the resultant torque required to accomplish the work would be 400 lb·ft.

Understanding the relationship between the output torque required and the physical set up a fluid system enables designers to determine the appropriate rotary actuator for each unique application.

The following video does an excellent job of illustrating the mechanics and the physics behind rotary actuators.

Water Recycling Application at Iron Ore Mine

Mining corporations need water - a lot of water - to make bare rock give up its valuable minerals.

Water is used for the extraction of minerals that may be in the form of solids, such as coal, iron, sand, and gravel. The category includes quarrying, and milling (crushing, screening, washing, and flotation of mined materials).

Not only is water used to expose the mineral, it must be carefully managed to prevent the release of contaminated water back into the environment.

There are multiple processes involving the management of water that require piping, valves and automation for water management.

  • The reuse of water used to extract the minerals from the other solids.
  • Managing surface water from rain, snow, and streams.
  • Capturing and recycling water from the mine site.
  • Storing water in evaporation ponds.
At a large Midwest iron ore mining facility, a Kinetrol Distributor was contacted to look at ways to lower the overall consumption of water in the main water treatment plant.

The Distributor designed and provided this characterized butterfly control valve, with a Kinetrol actuator, pneumatic positioner, and cone indicator.  The valve is used to recycle processed water back into the plant for reuse in the extraction process. The valve and actuator experiences a very high cycle rate (400 cycles per day).

Intercepting and diverting surface water
  • Intercepting and diverting surface water (rain and snowmelt runoff, streams, and creeks) from entering the mine site by building upstream dams to reduce the potential for water contamination from exposed ore and waste rock
  • Recycling water used for processing ore in order to reduce the volume of water requiring treatment
  • Capturing drainage water from precipitation at the mine site through the use of liners and pipes and directing the water to tailings dams in order to prevent potentially contaminated water from entering groundwater or flowing off site
  • Allowing the water to evaporate in ponds to reduce the volume of contaminated water; in dry regions, enough water may be evaporated that no water needs to be discharged, resulting in the containment of contaminates at the mine site
  • Installing liners and covers on waste rock and ore piles to reduce the potential for contact with precipitation and contamination of groundwater
- See more at: http://www.miningfacts.org/Environment/How-is-water-managed-and-treated-in-mining/#sthash.0qMpVdHr.dpuf

Segment Ball Control Valve with Vane Actuator, Pneumatic Positioner, and I/P Transmitter

Actuator and Positioner
Actuator and Positioner
Ball, plug and butterfly valves all belong to a class of valves commonly referred to as "quarter-turn" valves. This refers the 90 deg (angular) rotation required to go from full closed, to full open position.

In most cases standard ball, plug, or butterfly valves are not the best choice as control valves (where the process media has to be modulated or throttled). Standard ball, plug and butterfly valves usually introduce very non-linear, dynamic flow coefficients. Furthermore, they can introduce undesirable turbulence to your piping system.

As a means to linearize flow coefficients and reduce turbulent flow, the machining, or characterization, of the valve disk is done so that the machined shape allows for more optimized flow.

For ball valves in particular, machining the ball's flow port with a "V", or even by machining the ball more radically, can deliver excellent flow curves. A term for a more radically machined ball is the "segment ball" (sometimes called "segmented").  In the following video you can see how a Kinetrol pneumatic actuator, postioner, and I/P transmitter team up with a segment ball valve foe an excellent control valve.

Very High Cycle, Coal Power Plant Butterfly Valve Application

vane actuator
One moving part. Simply the best.

A coal fired power plant was using old Powell gate valves with dual air cylinders and volume tanks. Because of high cycle rate (the valve cycles open/closed every 30 seconds), the Powell gate valves were breaking down constantly - leaking at first, then failing. Downtime for repair was costing a fortune.
Kinetrol Model 12
Kinetrol Model 12

A local Kinetrol Distributor was called in to recommend a better solution. After discussing the capabilities of Kinetrol, the power plant decided to replace the gate valves with 6" high performance butterfly valves actuated with Kinetrol size 12 actuators, spring returns and limit switch packages. 

The result was a robust valve/actuator package that could handle the 120 cycles per hour required - truly a difficult application. As of two years in operation, both valve and actuator have been running reliably much to the delight of the power plant maintenance crew. 

High cycle coal fired power plant Kinetrol / HPBV application.

Innovative Approach to Add Manual Failsafe Handles for Large Quarter-Turn Valves


manual failsafe unit
Kinetrol manual failsafe unit
Let's assume you have an application where it's critical that a large, pneumatically actuated valve cannot be left unattended in the wrong position (opened or closed). Or maybe your application requires the use of a manual operator with a fire-safe fusible link. The problem though, is the valve you want to control has torque requirements much greater than the output of any manual failsafe unit can provide. 

Here's an innovate and effective way to incorporate a manual failsafe unit on large size ball, butterfly, or plug valves. 

Retrofit your large valve with a 3-way "L" port ball valve and a manual failsafe spring handle on the large valve actuator's inlet air supply port. 

This allows the opening of the valve with the manual failsafe handle. When the handle is released, the valve shuts automatically by venting the air to atmosphere, and allowing the springs in the actuator to close the valve. 

Size limitations on the valves are no longer an issue, and this will work on anyone's pneumatic spring return actuator (spring return required, will not work on double acting actuators). 


Manual Override for Larger Valves
Manual Override for Larger Valves

Limit Switches for Your Rotary Vane Actuator in Hazardous Areas

This Explosion Proof Limit Switch Box offers a wide range of signaling options in a compact corrosion resistant aluminum alloy housing available for close - mounting onto Kinetrol actuators or discrete mounting via a Kinetrol 05 square or industry standard VDI/VDE interface onto any make of rotary actuator. Easy to wire and set up with true industrial robustness.

Internally fitted options include AS interface digital communication and a 4-20mA, 2-wire, modulating angle retransmit circuit. The range of switches and terminal arrangements includes 2 or 4 switches and extra connections - allowing single point termination of wiring for limit switches and solenoid valves. This product is available to mount on Kinetrol models 03 - 30.

Vane Actuator for Pneumatic Power on Roll Lifting Machine

vane actuator on roll lifter
Kinetrol vane actuator on roll lifter.
There are many examples in machine design where the need for pneumatically driven, 90 ° rotation is required. One such application is a coil/roll lifting machine used to lift heavy rolls of material.

The machine is pneumatically operated and provides an expandable shaft that grabs and holds on to the center hole of the roll. The expandable shaft also prevents spiraling while lifting.  The roller can be tilted 90 ° so that it will be retrieved horizontally and vertically. A Kinetrol pneumatic vane actuator is used for the 90 ° movement because it provides very smooth rotation and has exceptional long cycle life.

See the equipment in operation below. Note the function and use of the vane actuator.



Thanks to the equipment manufacturer, JLM Teknik.

Kinetrol Actuators Chosen to "Bust Myths" on Popular TV Show

Kinetrol Actuators on MythBusters
A mechanical "soldier" busting myths.
Kinetrol actuators have a great reputation in many heavy industries such as power generation, chemical processing, and pulp and paper, but here's one industry that's easy to overlook - special effects engineering for television and movie production.

Case in point, the very popular science entertainment show "MythBusters" (produced for the Discovery Channel).

In an episode challenging the concept of destructive harmonics caused by an army marching in unison, MythBusters decided to create an "army" of mechanical feet to march in over a mock bridge. An important requirement was a mechanical rotational movement device that would allow for synchronized movement (simulating the legs of soldiers). Accurate and smooth control of multiple actuators so the cadence could be controlled was crucial.  Enter Kinetrol.

To see a 4 minute clip of the setup, test and results, see Kinetrol in action on the Breakstep Bridge Minimyth here.

Below are some images from the broadcast.

The "army" of marching feet.


One of the test rigs.

Pneumatic Actuator with 180 Degree Rotation for Your Multi-Port Valve

180 degree actuator
180 degree actuator
for multi-port valves.
So you need a pneumatic actuator with more than 90 degrees of rotation - most likely for a multi-port valve, or a custom louver or damper. Here's an excellent solution.

The simplicity and dependability of a 90 degree rotary vane actuator with a 2:1 step-up linkage mounted to the output shaft.

Kinetrol vane actuators provide factory fitted, direct mount linkage units for their models 02, 03, 05, 07, 09, 12, 14 and 16 actuators, giving a neat single unit with no mount kits or brackets. An added benefit is the linkage’s unique geometry gives constant 2:1 step-up, so that the output torque remains constant throughout the actuator's travel.

The all-steel mechanism of the linkage employs rolling contacts to minimize frictional losses and wear, and to maximize life. The linkage is lubricated for life, and encased in a robust, fully sealed die cast alloy casing. Exterior surfaces are protected by a corrosion resistant epoxy stove enamel finish. 

Standard adjustable end-stops on the 90 degree actuator can be used to set the angle of travel. The other end of the 90 degree actuator allows the full range of Kinetrol modular accessories to be fitted directly.

120 degree actuators are also available with adjustable end stops to give up to 133°.

Keeping Critical Turbine Lubrication Flowing

Kinetrol actuator on lube skid
Lube filter diverters
(courtesy of Kinetrol USA)
Power plants generate power 24/7. Their generator turbines are constantly running.  Turbines require lubrication to protect against wear and also for cooling. Maintenance of the lubrication system is critical, and switching between two lube skids is a common way to perform maintenance without shutting down the turbine.

Two 3-way valves and pneumatic actuators are used to re-direct flow between between two lube filter housings. The valve and actuator must be extremely reliable as a failure requires the turbine shutting done.

Steam Turbine
Steam Turbine
(courtesy of Wikipedia)
The automated valves provides an “on-the-fly” ability to transfer turbine oil service between filters, allowing the unit to run, and maintenance to be performed on the filter not in service. This is an extremely critical service to protect the turbine.


Kinetrol Actuator on Asphalt Plug Valve

kinetrol actuator on asphalt valve
Kinetrol actuator on asphalt valve.
A Mid-west asphalt manufacturer purchased Kinetrol actuators for use at two of their plants as a trial for possible standardization. This asphalt producer owns 7 asphalt mix plants and has been plagued with failing rack and pinion actuators. They're used to open and close their liquid asphalt valves (Homestead plug valves).

The service is extremely nasty, as the asphalt is hot, sticky and gets everywhere. The Kinetrol actuators were installed on 3” Homestead liquid asphalt plug valves with extended brackets and couplings to prevent the actuators from seeing over-temperatures. The valves are cycled 10 times per day.

Since the summer of 2014 they have installed 5 Kinetrol actuators and all are working without problems. The initial results are so positive the customer plans to standardize on Kinetrol Vane Actuators, and replace the rack and pinion actuators as they fail.

Rotary Vane Actuator on Specialty Valves, Dome Valves, and Double Flap Valves Used for Abrasive Powders and Bulk Materials

actuators for bulk material handling
Actuators on specialty
purpose valves and gates.
Kinetrol actuators, positioners, indicators and limit switches are the preferred valve automation products when it comes to severe service applications.  One of the most challenging is bulk material handling.

Used to to accurately control the flow of bulk solids as they are being discharged from silos, bins and hoppers, Kinetrol products automate the specialized gate and mixer valves, dome valves, double flap valves, pot type diverter valves, and flow control gate valves.

These specialty valves all have one thing in common - the actuators are exposed to extremely dusty and dirty atmospheres, with significant amounts of vibration, and are located in areas where downtime is very costly.

Kinetrol vane actuators are used because of their ruggedness and their reliability. Positioners can be used to provide control via a 4-20ma input signals. Kinetrol pneumatic actuators have a much smaller footprint, smoother operation compared to more conventional linear pneumatic cylinders, and consume much less air. This results in significant savings in energy costs.

This video presents a variety of bulk material valve applications Kinetrol actuators have been used on.

Bi-directional Positioning of Large Dampers Using Rotary Actuators and Declutchable Manual Override Gearbox

declutchable manual override gearbox
Rotary Actuator with declutchable
manual override gearbox
Rotary actuators are used in a great variety of applications. There are many designs of rotary actuator, including examples actuated by hydraulic pressure, pneumatic pressure and electric drives. It is also known to use position controllers to modulate the position of the actuator. All of these various designs have in common the purpose of providing an output torque which can be utilized to drive another device or mechanism.

One common application for bi-directional rotary actuators is the positioning of large damper valves controlling the flow of air and other gases along ducting in power generating plants. These dampers are often inaccessible, so it is not possible to install drives immediately adjacent the valve. In such circumstances, the rotary actuator drives the damper valve via a mechanical linkage. The rotary actuator will, in most cases, be used in conjunction with a position controller to provide for accurate control of the position of the damper valve.

In this, and other applications of rotary actuators, it can sometimes be desirable to provide for manual adjustment of the position of the actuator, for example during the initial set-up of a mechanism, or on failure of automatic actuator function. This is generally accomplished by using a so called declutchable manual override gearbox. The gearbox is mounted adjacent to the actuator and is connected to the output of the actuator. Drive is transferred via the gearbox to a drive shaft connected to the gearbox output. The gearbox includes a manually operable override, typically a wheel or lever, selectively engageable with the drive train in the gearbox. In normal operation, this manual override is de-clutched from the drive train. However, if it is desired to manually adjust the position of the actuator and the mechanism it drives, the manual override can be engaged.

A Cheesy Application for a Kinetrol Actuator & Positioner

Kinetrol Actuator on Steam Line
Kinetrol Actuator, Positioner and Spring on
Steam Line in Cheese Making Plant
High above the cheese factory floor, mounted to a 1-1/2 steam supply pipe is a lonely V-ported ball valve with a Kinetrol 097-120 actuator, spring  unit, and positioner. The valve is controlling 180 PSIG steam at 375 Deg. F. with the ambient air surrounding the actuator, positioner and spring unit at a constant 135 deg. F.

Its a tough application, and critical to keep running. Losing steam supply is very costly because of production losses and access to the valve is difficult.

The plant maintenance people tried a few of the more well-known valve/actuator packages without success. These packages would last a few weeks (a couple months at best), before failing. Frustrated and out of answers, the maintenance crew turned to a local Kinetrol Distributor salesperson for advice.

Knowing Kinetrol actuators, spring units and positioners are designed for the toughest applications, the salesperson specified the 097-120 on top of a Triad v-ported ball valve. Hopeful, but with little optimism, the maintenance crew installed the 1-1/2 control valve on the steam line and fired the system up.

For 11 months now (without any downtime), 24 hours a day, this lonely control valve, powered by a Kinetrol positioner and vane actuator, accurately throttles the steam supply and reliably keeps the cheese process line running.

Problem solved by Kinetrol!

The Kinetrol Universal Limit Switch

The Kinetrol universal limit switch box offers a wide range of signa ling options in a zinc alloy fully enclosed corrosion resistant case available for direct mounting onto Kinetrol rotary actuators,
or discrete mounting via an industry standard VDI/VDE interface onto any make of rotary actuator. Easy to wire and set up with real industrial-quality robustness. - Internally fitted options include AS interface digital communication and a 4-20 mA 2-wire modulating angle retransmit circuit.

Kinetrol Solves the Toughest Pneumatic Actuator Challenges

Kinetrol pneumatic vane actuators are world-renowned for their high cycle rate, durability, sealed spring unit, and precise control.

Kinetrol provides a rugged, corrosion-resistant pneumatic vane actuator with only a single moving part.

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.

The Kinetrol vane actuator is warranted to operate trouble-free for 4,000,000 (million) cycles.



For more information, contact:

KinetrolUSA
1085 Ohio Drive
Plano, Texas 75093
(972) 447-9443 phone
(972) 447-9720 fax
sales@kinetrolusa.com

An Extremely Accurate and Precise Valve Positioner

The EL electropneumatic positioner combines the precision and adaptability of a digital electronic control circuit with the smoothness and efficiency of Kinetrol's proven proportional servo valve, to give the best available 4-20mA positioning performance from rotary pneumatic actuators. 

This unbeatable performance is combined with the easiest available setup procedure, easiest access to all functions and options, easy connectibility, and a truly compact all-metal enclosure, plus unique easy-set isolated angle retransmit and limit switch options inside the same enclosure.

Features
  • Fast, smooth and precise control from a digital circuit and proportional servo valve 
  • Simple time saving field set up
  • Quick calibration via push buttons and LED feedback and easy reversal of rotation sense (clockwise/counter clockwise) without special tools or parts change. 
  • Universal application
  • The unit can be mounted in any orientation on to any quarter turn or linear application by connection via a NAMUR or Kinetrol square interface. 
  • Loop powered
  • No separate power needed, just a 4-20mA signal plus air supply. 
  • Integral options - easily retrofitted modules include:
    • Two wire 4-20mA isolated angle retransmit 
    • Mechanical or inductive position indicator switches (general or hazardous areas) 
    • Clear Cone high visibility indicator 
    • Threaded conduit entries or DIN plugs for external connection.
  • Intrinsically safe approved options 
  • Weatherproof, compact and robust metal housing 
  • Zero backlash coupling with easily adjustable switch strikers 
  • Vibration and shock resistant to 4G 
  • Built in gauge ports/external connections

Why Kinetrol Pneumatic Vane Actuators Are Superior in Design - in 20 Sec...

It's a bold statement, but it's backed up with decades of proven performance, millions of actuators in the field, and many happy customers.




  • Single moving part - Simplest and most reliable mechanism for quarter-turn rotary actuation.
  • Close couple control modules - Fail-safe spring returns, limit switches, positioners and solenoid valves all close couple to the actuators.
  • No cranks or gearing - No power loss or backlash - allows accurate positioning.
  • Durable corrosion resistant finish
  • Long maintenance-free life - Up to 4 million operations guaranteed.
  • Compact - space saving - efficient - Best torque/size package available, fast operating speeds, best air consumption, proven design.
  • Millions of units in trouble free service all over the world
  • Choice of male or female output drive square - easy to interface to application
  • Unique serial number for identification and traceability


Kinetrol USA
1085 Ohio Drive
Plano, Texas 75093
(972) 447-9443 phone
(972) 447-9720 fax
sales@kinetrolusa.com

Work with a Valve Automation Professional on Your Next Project for Improved Outcome and Efficiency

Valve Sales Professional
The valve automation
sales professional
will help with your next 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.

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.

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.

rotary vane actuator
Article courtesy of Kinetrol USA
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.

Use Vane Actuators on the Toughest Applications

Vane Actuator
Use vane actuators on
tough applications.
The "vane type" pneumatic valve actuator is well regarded for its simplicity in design and extremely long life, even in the toughest valve actuation applications.

The heart of this simple design, and the primary reason for such long life, is the "single moving part" - a one-piece shaft and vane that moves in response to the air pressure differential on either side of the vane. A rotary vane actuator has no gears or yokes which will wear and cause problems over time. Wear, movement slop, and internal corrosion are the most typical modes of failure for rack and pinion and scotch yoke actuators.

The video below illustrate the elegance and simplicity of the rotary vane actuator and its "single moving part".

Louver and Damper Control with Vane Actuators

Besides pneumatic valve actuation, Kinetrol vane actuators are used widely on controlling industrial and commercial louvers and dampers.

The video below gives you a short visual demo of a louver being opened, closed and positioned with a Kinetrol vane actuator and electro-pneumatic positioner.

Louvers and dampers are used to stop or regulate the flow of air inside a duct, chimney, air handler, or other air handling equipment.

Some varieties of dampers are:
  • Louvered Inlet Box Dampers
  • Radial Inlet Dampers
  • Variable Inlet Vane (VIV) Dampers
  • Vortex Dampers
  • Discharge Dampers
Industries that use dampers include:
  • Petrochemical
  • Oil & gas
  • Power generation
  • Construction industries

Pneumatic Actuators in Marine Environment (Offshore Rigs)

Kinetrol in Marine Environment
High density, cramped spots are ideal
for Kinetrol actuators and accessories.
Offshore oil rigs present some special challenges to pneumatic actuator manufacturers. First, the corrosive marine environment takes a harsh toll on the internal and external parts of a typical actuator. Rack and pinion actuators are particularly susceptible.

Because rotary vane actuators, (such as Kinetrol) or their spring units, don't "breathe" ambient air, they have great immunity to internal corrosion. Also, a very durable, epoxy enamel finish and stainless steel hardware provide maximum external protection.



Kinetrol in Marine Environment
Ideal for corrosive, marine installation.
Another challenge for offshore use is the very limited space available. Facilitation of large scotch yoke actuators, is quite difficult. Actuators such as Kinetrol's compact vane design with integral direct-mount limit switch make it a perfect choice in applications where space is at a premium. In these cramped and below grating installations you want the long maintenance-free life that you can install with confidence for years of service.

Click on images for larger view.
Kinetrol in Marine Environment
Low maintenance is important
in hard to get to places

Kinetrol in Marine Environment
Long life where access is a problem.

Kinetrol Pneumatic Rotary Vane Actuator Product Selection

Here is an easy-access, online vane actuator catalog from Kinetrol that includes pneumatic actuators, spring return units, positioners, indicators, limit switches, solenoid valves, and other valve actuation equipment.

Elegantly Engineered Pneumatic Valve Actuators. A Simple, Single Moving Part

Vane Actuator
One moving part. Simple. Elegant.
According to Wikipedia, elegance is "a synonym for beauty that has come to acquire the additional connotations of unusual effectiveness and simplicity." In engineering terms, "a solution may be considered elegant if it uses a non-obvious method to produce a solution which is highly effective and simple. "

When you compare the mechanics of various other pneumatic valve actuators, such as rack and pinion or scotch yoke with their internal gears, bushings and bearings, you immediately understand that simplicity is sacrificed and the design is certainly not elegant.

gears
Actuators with gears wear.
When gears mesh, there is friction. Friction causes heat and wear, which effects the mechanical life of the actuator. Friction converts kinetic energy into thermal energy and can have dramatic consequences if left unchecked. Another important consequence of friction is wear, which may lead to performance degradation and/or damage to the internal components of a rack and pinion or scotch yoke actuator.

"Fretting wear" is caused by the repeated cyclical rubbing between two surfaces (gears in the case of scotch yoke or rack and pinion actuators) and over a period of time, will remove material from one or both surfaces.

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".

A well designed vane actuator 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.

For more information, contact:

Kinetrol USA
1085 Ohio Drive
Plano, Texas 75093
(972) 447-9443 phone
(972) 447-9720 fax
sales@kinetrolusa.com

Why the Rotary Vane Actuator Design is Superior to Rack and Pinion & Scotch Yoke Designs

When it comes to pneumatically actuating an industrial quarter-turn valve, you basically have only three types of mechanical technologies to choose from: rack and pinion, scotch yoke and the rotary vane design. This post describes why a rotary vane design is the clear winner when it comes to efficiency and reliability.

First, let's describe how rack and pinion and scotch yoke actuators work.

A rack and pinion actuator is comprised of two opposing pistons, each with its own gear (referred to as the "rack"). The two piston racks are set against a round pinion gear. As pressure increases against one side of each piston, each rack moves linearly against the opposite sides of the pinion gear causing rotational movement. This rotational movement is used to open and close a valve. Pretty basic stuff. See the animation (provided by Wikipedia) below for a visual understanding.

rack and pinion
Note rack and pinion gears
and how they are prone to
wear and slop.
A scotch yoke actuator relies on the scotch yoke mechanism to convert linear movement into rotary motion. In this case, a piston is coupled to the sliding yoke, which in turn moves a fixed pin on the shaft of the actuator to provide rotation. As one side of the piston is pressurized, the piston forces the yoke to move linearly, which allows a slot in the yoke to drive the pin on the actuator shaft. See the animation (from Wikipedia) below for clarification:
scotch yoke design
Scotch yoke operation. Easy to see its highly
susceptible to wear and resulting slop.

Both of these valve actuator mechanisms use several interconnected, mechanical moving parts. As a result, they are very susceptible to wear.

It All Comes Down to "A Single Moving Part"

The vane actuator has only one moving part and there is no linear-to-rotary conversion. An internal vane moves uniformly in response to inlet air pressure, without gears, slots, or levers. This is a clear advantage when you consider wear and tear, and also machine efficiency. See the video below for a visual explanation.




Vane = Simple, reliable design --------- Piston = Complicated, less reliable

One moving part --------------------------- Many moving parts
No O-rings ---------------------------------- Several sets of O-rings
Dynamic Memory Seals ------------------ Static seals
No linear to rotary motion ---------------- Linear to rotary = friction/wear
Spring isolated ------------------------------ Spring exposed to atmosphere
Very accurate control ---------------------- Hysteresis = poor control
Non-pressurized shafts -------------------- Pressurized shafts
4 million operations ------------------------ 500,000 to 1 million operations

Operation of the Kinetrol Model 20 Vane Actuator with Limit Switch

The following video demonstrates the Kinetrol Model 20, double acting, pneumatic vane actuator as it closes a large butterfly valve.

The Model 20 actuator is capable of delivering 89,000 inch pounds of torque at 80 PSI. The unit you see below is equipped with a dual coil, 4-way solenoid valve to control air flow to either side of the actuator, as well as control the opening / closing time. The actuator below also is equipped with a Kinetrol Universal Limit Switch with visual indication and internal electrical contacts.


EL Electropneumatic Positioner

The EL positioner controls airflow to an actuator and moves it to a position determined by a 4-20mA signal and using a unique low power proportional servo valve.

The microprocessor in the loop-powered 4- 20mA position circuit reads the signal via one channel of a 12-bit A-D converter, reads the position voltage from the feedback potentiometer via the second channel of the

A-D converter, and compares the two. If it detects a position which is different from that required by the signal, it changes the output to the servo valve, in order to drive the actuator in the direction required to reach the correct position. As the actuator moves, the feedback potentiometer voltage changes and the microprocessor continually calculates the adjustments required for the servo valve in order to guide the actuator accurately into position. The microprocessor is programmed with a sophisticated but compact algorithm which allows this critical dynamic valve adjustment to be made correctly. This in turn gives optimal results with any actuator/load combination - slow or fast, low or high friction, low or high inertia. All can be optimized by tuning the PGAIN and DAMP push buttons via the positioner circuit push buttons.



Actuators for Sludge Blowdown Valves in Municipal and Industrial Water and Wastewater Treatment Plants

Kinetrol Valve Actuator App Note
Large, bulky and unreliable old sludge
blow-down valve actuator packages.
Sludge blowdown valves are used in water and wastewater treatment systems that separate solids prior to filtration. They are typically plug valves with double acting pneumatic actuators that operate on a controlled time frequency. The frequency depends on the amount of solids in the media and cycle times of every 20 minutes are common.

The pneumatic actuators that are supplied with the original equipment have been known, in some cases, to have a short performance life due to the cycle frequency and environment. Some end users have experienced the original actuators failing in 3 - 4 months. Customers who have upgraded to Kinetrol actuators have experienced performance lives of over 5 times this and still counting.


Kinetrol Actuator App Note
New Compact and highly reliable Kinetrol install.

Kinetrol Actuator App Note
Getting ready to remove old actuators.

Welcome to the Kinetrol USA Blog

We'll be using this site as a place to educate people about the advantages of rotary vane actuators and showcase interesting and unique applications.

We'll try to post as often as possible and keep the site fresh. Please check back frequently.