Exploring the Superior Features of Vane Actuators in Contrast to Rack & Pinion and Scotch-Yoke Designs

Pneumatic actuators are vital components in many industrial processes, enabling the automation of valve and damper operations. The three most commonly used types of pneumatic actuators are vane, rack and pinion, and scotch yoke. This post provides an analysis of the technical design differences between these actuators, focusing on the advantages of Kinetrol vane actuators. We will also discuss why Kinetrol vane actuators last longer in industrial valve and damper applications, and how they provide a lower cost of ownership than other types of pneumatic actuators.

Design Differences Between Vane Actuators, Rack and Pinion Actuators, and Scotch Yoke Actuators

Kinetrol Pneumatic Vane Actuators

Kinetrol pneumatic vane actuators utilize a simple yet effective design consisting of a central shaft connected to a flat vane inside a semi-cylindrical housing. When pressurized air is applied to the housing, the vane rotates the central shaft, creating a rotary motion that operates the valve or damper.

Pneumatic Rack and Pinion Actuators

Pneumatic rack and pinion actuators consist of a piston connected to a rack, which engages with a pinion gear on the output shaft. As the piston moves linearly, the rack converts this motion into rotation through the pinion gear, driving the output shaft.

Scotch Yoke Actuators

Scotch yoke actuators employ a slotted yoke mechanism that translates linear motion from a piston into rotary motion. The piston rod has a pin that engages with the yoke, which in turn is connected to the output shaft. As the piston moves, the pin slides within the yoke slot, causing the yoke to rotate the output shaft.

Advantages of Kinetrol Pneumatic Vane Actuators

Simplicity and Compactness

Kinetrol vane actuators boast a simple design with fewer moving parts compared to rack and pinion or scotch yoke actuators. This simplicity results in a more compact and lightweight unit, which requires less space and is easier to install and maintain.

High Torque-to-Size Ratio

Kinetrol vane actuators have an exceptional torque-to-size ratio, providing more torque per unit size compared to other actuators. This enables Kinetrol actuators to deliver powerful performance even in space-constrained applications.

Less Friction and Wear

The design of Kinetrol vane actuators minimizes contact between moving parts, resulting in reduced friction and wear. This leads to a longer service life and lower maintenance requirements.

Smooth, Precise Control

Kinetrol actuators provide smooth and precise control of the valve or damper position, with minimal backlash or hysteresis. This ensures accurate and consistent process control, essential for maintaining product quality and efficient operations.

Longer Life in Industrial Valve and Damper Applications and Lower Cost of Ownership

Kinetrol vane actuators last significantly longer in industrial valve and damper applications due to their design, which minimizes friction and wear. Their simple construction and fewer moving parts result in reduced likelihood of component failure and increased resistance to harsh operating conditions. This translates into fewer breakdowns, less downtime, and lower maintenance costs.

The cost advantages of Kinetrol pneumatic vane actuators stem from their durability, ease of maintenance, and lower energy consumption. With fewer components to replace, lower maintenance requirements, and longer service.

For more information, contact:
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.

WEFTEC 2017

WEFTEC is recognized as the world’s largest annual water quality technical conference and exhibition, providing extensive educational opportunities and unparalleled access to the field’s most cutting-edge technologies and services.

WEFTEC's expansive show floor provides unparalleled access to the most cutting-edge technologies in the field; serves as a forum for domestic and international business opportunities; and promotes invaluable peer-to-peer networking among registrants.

The conference provides insights and products for water and wastewater technologies including:

• Collection Systems - Management, operations and maintenance, infrastructure, overflow reduction, wet weather planning, watershed approaches, and regulations
• Energy Conservation and Management - Resource recovery, combined heat and power, biogas optimization
• Membrane Technologies - Application in wastewater and water reuse, innovations, enhanced performance, regulatory compliance
• Plant Operations and Treatment - Innovations, technologies, processes, and proven solutions in water and wastewater treatment; including nutrient removal and odor control
• Regulations - CMOM/SSO Rules, TMDL/Watershed Rules, Nutrient Trading, and NPDES Phase II
• Research - Leading edge process applications in water and wastewater treatment and recent developments
• Residuals & Biosolids - Incineration, disposal, reuse through land application, research, regulations, politics, and public perception
• Stormwater - Treatment, green infrastructure, wet weather management, modeling
• Utility Management - Asset Management and financial planning for infrastructure, technology, regulatory compliance, and security; including environmental management systems (EMS)
• Water Reuse/Recycling - Research, regulations, emerging technologies, proven processes
• Water Quality & Watershed Management - Stormwater, wet weather, and watershed issues

Kinetrol is exhibiting again this year and will be in booth 4136. Please come by and visit us if you attend.

Exhibition Details:
McCormick Place | Chicago, IL
Exhibition: October 2 - 4, 2017
Hours: 8:30 am - 5:00 pm daily
COME VISIT US AT BOOTH 4136

Integral Vane-Shaft Actuators Best for High Cycle Rate and Modulating Applications

Internal view of vane actuator. Note the
single piece vane/shaft design.

Rack and pinion and scotch yoke type pneumatic actuators depend on gears to transfer torque and movement, while integral vane-shaft actuators have no gears (or linkages). As a result,  integral vane-shaft actuators are the hands-down choice for high cycle rate and modulating valve/damper actuation.

Why? Because of the mechanical problems inherent to the use of gears.

According to Wikipedia, "A gear or cogwheel is a rotating machine part having cut teeth, or cogs, which mesh with another toothed part to transmit torque."

The primary disadvantages to gears are:

• Friction
• Fretting Wear
• Backlash

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".

For pneumatic actuators with very low cycle rates, or ones that are not used for modulating service, internal gears may be acceptable. However, for applications where there are high cycle rates, or require accurate modulation, the use of a single machined vane actuator with integral shaft is preferred. The reason? No friction, wear, or backlash. 100 percent of the movement of the vane is transferred to the shaft without loss or hysteresis.

For any questions about applying the most appropriate type of actuator for any valve or damper application, call Kinetrol at 972-447-9443 or visit http://www.kinetrolusa.com.

A Basic Description of Valve Actuators

Automated plug valve with
actuator, limit switch, and indicator.

Valves are used to control the flow of fluids in process systems. In order to meet the needs of a process system some method of changing the positions of the valve is needed. 

Some valves can be operated with hand wheels or levers, but some valves have to be open and closed or throttled frequently. Manually positioning valves in these types of situations is not always practical. So instead of hand wheels or levers, actuators are used to position the valves. 

An actuator is a mechanism that moves or controls a device such as a valve. Actuators reduce the need for operators to go to every valve that needs repositioning and operate the valve by hand. When actuators are used, valves can be repositioned from a central remote location, such as a control room. This is very important in processes where a number of valves have to be repositioned accurately and quickly.

There are three basic types of actuators pneumatic actuators, hydraulic actuators, and electric actuators. Pneumatic actuators use air pressure to produce motion to position the valve. They're probably the most common type of actuator used in process systems. Actuators that are powered by a pressurized liquid, such as hydraulic fluid, are called hydraulic actuators. Compared to pneumatic actuators, hydraulic actuators of the same size are usually more powerful. Electric actuators use electricity to produce motion. They usually fall into one of two general classifications: solenoid actuators or motor-driven actuators. 

Regardless of the type of actuator used with valves, actuators are normally part of process control systems. From a control room, valves with actuators can be quickly and accurately positioned to deal with frequent flow changes. 

Valve actuators operate to position valves in response to signals from controllers. Controllers are part of the instrumentation systems that monitor plant processes and response to variations in the processes. Basically a controller is a device that receives an input from another part of the instrumentation system, compares that input to a set point, and sends out a corrective signal to regulate the value of a process variable such as temperature, pressure, level, or flow. 

Generally, actuators are used with valves that are designed for throttling or regulating flow. Valves that are used to automatically throttle flow are generally referred to as control valves. However some on-off or isolation valves may also require actuators. Although these isolation valves may require actuators, they're not commonly referred to as control valves. Control valves can be either linear that is the stem moves the valve disc up and down as in globe and gate valves, or they can be rotary which means that they're positioned by rotation. Butterfly valves and ball valves, which open or closed with a 90-degree turn, are examples of rotary control valves.

Troubleshooting & Set Up Guide for Kinetrol EL Positioners

Kinetrol EL Positioner

The Kinetrol EL Positioner operates by modulating the percent opening / closing of a valve or damper by converting an electrical signal to a pneumatic output, which in turn, regulates the position of a pneumatic actuator.

In terms of response and accuracy, the EL Positioner is arguably one of the best electro-pneumatic positioners in the world,  particularly when used in tandem with a Kinetrol vane actuator.

The document below provides an illustrated troubleshooting and set-up guide for the EL electro-pneumatic positioner and is available to support the all the units installed in chemical, petro-chemical, water treatment, power generation and other applications across the world.

Illustrated Troubleshooting & Set Up Guide for Kinetrol EL Positioners from Kinetrol USA