Showing posts with label valve automation. Show all posts
Showing posts with label valve automation. Show all posts

Wednesday, June 19, 2019

Mounting and Adjusting a Rack & Pinion Actuator


A-T Controls is a global leader in the design, manufacturing and sale of manual & automated process valves for all types of industries.

This video details the steps required to mount and adjust a TRIAC rack and pinion actuator to an AT Controls ball valve.

Piping Specialties sells, services, and automates A-T Controls valves and TRIAC actuators in New England.

For more information, contact Piping Specialties by calling 800-223-1468 or visiting https://psi-team.com.

Saturday, February 23, 2019

Types of Pneumatic Valve Actuators

Scotch-yoke actuators
Scotch-yoke actuators (Morin)
Pneumatic valve actuators all provide the same function:  They convert air pressure to rotational

movement and are designed to open, close, or position a quarter-turn valve.  These include ball valves, plug valves, butterfly valves, or other types of 90 degree rotational valves.

The basic design variations of pneumatic valve actuators are as follows:

  • Rack and pinion
  • Scotch-yoke
  • Rotary vane

Let's review each of these in detail:

Rack and Pinion Actuators

Rack and pinion actuator
Rack and pinion actuator (Unitorq)
These actuators are sometimes referred to as, “lunch box,” because they, well, look like a lunch box. This actuator uses opposing pistons with integral gears to engage a pinion gear shaft to produce rotation. They are usually more compressed than a scotch yoke, have standardized mounting patterns, and produce output torques suitable for small-to-medium sized valves.  Rack and pinion nearly always include standard bolting and coupling patterns to directly attach a valve, solenoid, limit switch or positioner.  One of their features include several smaller coil springs mounted internally, which provide the torque to return the valve to its starting position.

Scotch-yoke Actuators 

Scotch-yoke actuators
Scotch-yoke actuators internal view.
These actuators come in a multitude of sizes, but are usually used on larger valves because they can produce a very high torque output.  They employ a pneumatic piston mechanism to transfer movement to a linear push rod.  That rod, in turn, engages a pivoting lever arm to provide rotation. Spring return units have a large return spring module mounted on the opposite end of the piston mechanism working directly against the pressurized cylinder.

Rotary Vane Actuators 

Rotary vane actuators
Rotary vane actuator animation.
These actuators are usually used when the application requires a significant space savings.  They take up less space when comparing size-to-torque with rack and pinion and scotch yoke. Rotary van actuators also benefit from a reputation of longevity.  They contain fewer moving parts than other types of pneumatic valve actuators.  Rotary vane actuators use externally mounted, helically wound "clock springs" for their spring return mechanism.

These style of valve actuators can all be secured with direct acting or spring return versions. Direct acting actuators use the air supply to move the actuator in both directs (open and close). Spring return actuators, as the name describes, uses springs to move the actuator back to its "resting" state. Converting a version 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.

When considering the choice of pneumatic valve actuators, your decision comes down to size, power, torque curve and the ease of adding peripherals. To ensure that your valve actuation package will be optimized for safety, longevity, and performance, the advice of a qualified valve automation expert should be sought out. That expert will be able to help you with the best selection of the appropriate valve actuator for any quarter turn valve application.

For more information on valve actuation, contact Piping Specialties, Inc.
https://psi-team.com
800-223-1468

Thursday, January 31, 2019

MOGAS Industries Authorized Valve Automation Center


Piping Specialties, Inc. is an authorized Valve Automation Center for MOGAS Industries, Inc. serving New England and the Northeast U.S.A. MOGAS is the leading manufacturer of severe service ball valves for extreme industrial applications.

Piping Specialties, Inc.
https://psi-team.com
800-223-1468

Sunday, September 30, 2018

Piping Specialties / PSI Controls: New England's Preferred Source for Industrial Valves, Valve Automation, and Process Instrumentation

Founded in 1975, with offices in Portland, Maine and Danvers, Massachusetts, PSI has earned their reputation as New England's premier supplier of industrial valves, valve automation, process instrumentation and specialty process equipment.

PSI specializes in engineered products for these industries:

  • Power Generation
  • Pulp & Paper
  • LNG / LPG / Natural Gas / Gas Storage & Distribution
  • Pharmaceutical / BioTech
  • Food and Beverage
  • HVAC
  • Water & Wastewater

Piping Specialties, Inc / PSI Controls
https://psi-team.com
800-223-1468

Wednesday, April 18, 2018

Piping Specialties and PSI Controls

Piping Specialties was founded in 1975 with the mission of providing specialty valves and mechanical products and unsurpassed customer service to industrial users throughout the Northeast. Over the years our company has experienced steady, sustainable growth in both our customer base and product offerings. With offices in Danvers, MA and Portland, ME, we are geographically well-positioned to serve all of the Northeast.

PSI delivers our products and services through our 3 operating divisions:
  • Piping Specialties: valves and mechanical specialties.
  • PSI Controls: automated valves and process instrumentation & controls.
  • PSI Services: valve automation, valve and instrument repair, calibration, and turnkey installation and field services.


Friday, March 23, 2018

The Important Role of Valve Actuators

Valve actuation
Actuator being positioned on large ball valve.
(Piping Specialties)
Valves are essential to modern industry. The prevalence of valves in engineering, process control, and manufacturing across the world is astounding, and each valve application requires it's own performance standard. Product safety, quality, and consistency is dependent on the proper selection of valves, whether ball, butterfly, gate or globe. Along with proper selection of the valve type, selecting the proper valve operator is critical for controlling the process, assuring quality, and protecting equipment and personnel.

Actuators are powered mechanisms that position valves between open and closed states; the actuators are controllable either by manual operators, or as part of an automated system where the actuator responds to a remote control signal. The valve actuator is as important to the valve, as the valve is to the industry in which it functions.

Thanks to actuators, multiple valves can be controlled in a process system in a coordinated fashion; imagine if, in a large industrial environment, engineers had to physically adjust every valve via a hand wheel or lever! It is completely impractical from a logistical and economic perspective. Actuators enable automation to be applied to valve operation throughout the facility.

Valve actuators serve as the interface between the control intelligence and the physical movement of the valve. The most obvious advantage of valve automation is risk mitigation, where, as long as the system is functioning correctly, critical calamities in either environmental conditions or to a facility can be pre-empted and quickly prevented.

Rack and pinion actuators
Rack and pinion actuators.
(Flo-Tite)
Regardless of its power source, be it electricity, hydraulic fluid, air pressure, or other, all valve actuators share a singular purpose; to produce linear or rotary motion under the command of a control source. Depending on the design and settings of the actuator, valves can be closed, fully open, or somewhere in-between. Modern actuation technology allows for remote indication and control of valve position, as well as other diagnostic and operational information.

Pneumatic actuators utilize air pressure as the motive force which changes the position of a valve. Hydraulic actuators depend on non-compressible liquids under pressure to provide the motive force. Electric actuators, either motor driven or solenoid operated, rely on electric power to change valve position.

As automation continues to advance throughout every industry, manual valve operation makes less and less sense. Component integration, lower cost and universally accepted valve communications systems are becoming the norm. Simple, seldomly operated, basic valves are now outfitted with inexpensive automation packages that allow them to be monitored as part of the entire process control system.

Automated valves
Automated valves ready for shipment.
Thanks to their versatility, reliability, and technological advances, valve actuators provide safe and repeatable operation in critical processes all over the world.  Just as industries are the backbones of societies, valves are key building blocks to industrial processes, with actuators ensuring both safe and precise operation.

For information on valve automation, contact Piping Specialties by calling 800-223-1468 or by visting https://psi-team.com.

Tuesday, November 28, 2017

Understanding Rack & Pinion Pneumatic Valve Actuators

Internal view of rack and pinion actuator.
Internal view of rack and pinion actuator (UniTorq)
Rack & Pinion actuators are designed for operating quarter-turn valves such as butterfly, plug, and ball valves or for actuating industrial or commercial dampers.

The rotational movement of a rack and pinion actuator is accomplished via linear motion and two gears. A circular gear, referred to a “pinion” engages the teeth of a linear gear “bar” referred to as the “rack”.

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

Rack and Pinion Animation
Rack and Pinion Animation
Pneumatic actuators have cylinders with pistons and springs that provide the linear movement. When one side of the piston is pressurized with air, gas or oil, the pinion bearing turns in one direction. When the air, gas or oil from the pressure side is vented, a spring (spring-return actuators) may be used to rotate the pinion gear in the opposite direction. A “double acting” actuator does not use springs, instead using the air, gas or oil supply on the opposing side of the piston to turn the pinion gear in the opposite direction.

Pneumatic pneumatic rack and pinion actuators are compact and save space. They are reliable, durable and provide a good life cycle. Mechanical wear of the heads and seals are their primary disadvantage.

Most actuators are designed for 100-degree travel with clockwise and counterclockwise travel adjustment for open and closed positions. World standard ISO mounting pad are commonly available to provide ease and flexibility in direct valve installation.
Rack and Pinion Actuator
Rack and Pinion Actuator (UniTorq)
NAMUR mounting dimensions on actuator pneumatic port connections and on actuator accessory holes and drive shaft are also common design features to make adding pilot valves and accessories more convenient.

Feel free to contact Piping Specialties, Inc. at www.psi-team.com or 800-223-1468 with any questions you may have about valve actuation.

Thursday, July 20, 2017

PSI Controls and Piping Specialties Intro Video

For those who may not know us, please take a minute to watch our 1 minute intro video.

Welcome to the PSI Controls and Piping Specialties Blog

We hope you find our product and application articles helpful and informative. Our goal is to do our part in improving access to process control information and knowledge through Internet resources. Please feel free to reach out and contact us if you ever have a question or comment.

Sincerely,
PSI Team