Bi-directional Positioning of Large Dampers Using Rotary Actuators and 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, 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 Universal Limit Switch from Kinetrol USA

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

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.

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.