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

The Increasingly Important Role of Industrial Valve Actuators

Industrial Valve Actuators

Valves are critical components of industries that provide the backbone of the modern world. Because valves are standard in engineering, mechanics, and science, each valve must perform to a specific standard. The valve actuator is as crucial to the valve as the valve is to the industry in which it operates.  

Actuators are powered devices that move valves between open and closed states; the actuators can be controlled manually or as part of an automated control loop. The actuator responds to a remote control signal. Valve types can be closed, fully open, or somewhere in between, depending on the valve and actuator combination. Current actuation technology enables remote indication of valve position as well as other diagnostic and operational data. Regardless of its power source, whether electric, hydraulic, pneumatic, or another, all actuators create either linear or rotating motion when controlled by a control source. 

Multiple valves in a process system are operated in a coordinated manner thanks to actuators; imagine if engineers in a vast industrial environment had to change every valve through a hand wheel or lever physically! While such a manual system may produce jobs, it is, unfortunately, logistically and economically impractical. Actuators make it possible to automate valve action. 

Pneumatic actuators use air pressure as a driving force to adjust the position of a valve. Hydraulic actuators are devices that rely on pressurized fluids. Electric actuators, whether motor-driven or solenoid-driven, use electricity to move the valve trim into position. Changes in valve position provide the needed response to maintain the desired process condition. Signals from controllers constantly monitor the process and evaluate inputs, subsequently adjusting the actuator's motion.

Manual valve operation and regulation are becoming less common as automation gains traction across many industries. Valve actuators serve as the link between control intelligence and physical valve movement. The timeliness and automation advantages of valve actuators also serve as enormous assistance in risk mitigation. Severe tragedies in either environmental conditions or a facility can be pre-empted and rapidly stopped as long as the system is functioning correctly. Manual actuators rely on the hand operation of levers, gears, or wheels in general. Still, valves that are frequently changed (or that exist in remote areas) benefit from an automatic actuator with an external power source for various practical reasons, most notably being located in an impractical area for manual operation or complicated by hazardous conditions. 

Actuators serve as industrial keystones to one of the essential control elements of industries worldwide due to their variety and tiered usage. Valves are vital building blocks of industrial processes, just as industries are the backbones of society, with actuators serving as an invaluable device assuring both safe and precise functioning.

Swanson Flo produces tested, certified, and exceptionally reliable actuated valves for fully automated essential valve systems with optimum fit, highest performance, and most extended life. Swanson Flo professionals combine decades of experience and knowledge with a wide range of readily available components that are carefully selected to provide customers with the highest quality and value possible.

Swanson Flo
https://swansonflo.com
800-288-7926

Full Service Valve Automation


From simple pneumatically or electrically actuated valves, to fully automated critical valve systems, Swanson Flo delivers tested, certified, and extremely reliable product every time. Actuated valve assemblies precisely engineered for the best fit, highest performance, and optimal life.

With decades of combined experience and knowledge, Swanson Flo technicians match state-of-art components with best-in-class manufacturers and deliver carefully crafted valve packages.

Swanson Flo customers always receive the highest quality and best value possible. Their strong reputation was built upon:
  • The largest, most comprehensive facility in the Midwest.
  • In-house capabilities for all electric, pneumatic and electro-hydraulic actuators.
  • Experienced design engineering and fabrication.
  • Support for assembly of all valve, actuator, monitor and positioner technologies.
  • Complete solution for testing and serialization.
800-288-7926

What Are Valve Positioners?

Digital Positioner
Digital Positioner (Valtek)
A valve positioner is used in combination with a valve actuator to precisely position a valve so that optimum flow accuracy may be achieved. The positioner does this by measuring a the process variable, comparing it to a desired condition (set point) and then pneumatically, electrically, or hydraulically changing the valve disc, globe, plug or ball position until the difference between the set point and actual position is zero.

Valve positioners are key elements in a closed loop control system where the final control element is a valve. They assist in maintaining tight control, overcoming the realities of imprecise calibration, differential pressure across the valve, valve wear and a host of other process control challenges.

A valve positioner responds to a signal from some type of master control system, typically a distributed control system (DCS), a programmable logic controller (PLC), or PID controller. The control system reads a signal from a process sensor (flowmeter, temperature sensor, pressure sensor, etc...) and compares that reading to the desired setpoint. A corrective signal, based on the difference,  is provided to the valve positioner which re-adjusts (if necessary) the valve position to bring the system in to equilibrium.

Valve positioners are available with pneumatic, electrical, electro-pneumatic, and digital operation. Here is a brief description of each:

Pneumatic
Pneumatic Positioner
Pneumatic Positioner (Valtek)
Pneumatic positioners receive pneumatic signals (3-15 or 6-30 PSIG). The positioner then throttles supply air to the valve actuator to move the valve to the required position. Pneumatic positioners are intrinsically safe and can provide a large amount of force to close a valve.

Electric
Electric valve positioners receive an electric signal, usually 4-20 mA, 1-5 VDC, 2-10 VCD or 0-10 VDC and generally drive the motors in electric actuators. They perform the same function as pneumatic positioners do, but use electricity instead of air pressure as an input signal.

Electro-Pneumatic
Electro-pneumatic Positioner
(PMV)
Electro-pneumatic valve positioners contain internal I/P (current to pneumatic) modules that converts the electrical input signal to a pneumatic output (4-20 mA to 3-15 PSIG for instance). Very similar to a pneumatic positioner except that its input is electrical.

Valve positioners are used throughout the process industries including power, pharmaceutical, chemicals, oil and gas, food and beverage, pulp and paper, refining and petrochemicals, pipelines, and many other processes.

For more information on valve positioners, contact Swanson Flo by visiting https://swansonflo.com or by calling 800-288-7926.

Worm Gear Valve Operators

Worm gear operator
Worm gear operator (WedgeRock)
Every industrial valve needs a means to open and close, allowing the process to flow.  Worm gear actuators provide a mechanical advantage to make hand operation possible for most quarter-turn butterfly, ball, and plug valves as well as quarter-turn and multi-turn dampers. Gears provide mechanical advantage to an operator providing the force required to open and close the valve.  Torque can be increased or decreased by changing the size of the hand wheel. Manual worm gear operators are relatively inexpensive and require little involvement beyond their in the process line.

Download the WedgeRock RW Series IOM PDF here.

Swanson Flo Performance

Specialists in valves, automation and instrumentation, Swanson Flo Performance sets the standard for process control optimization and training that maximizes plant uptime, safety and operating efficiency.
  • Valve automation center 
  • Experienced staff of factory-certified technicians 
  • Responsive on-call repair and service 
  • Extensive OEM parts inventory 
  • Third party audited standards 
  • The region’s widest range of industry application experience 
  • Comprehensive multi-brand process equipment knowledge
Please take a minute to watch the video below for more information.

Your Partner for Process Control Automation: Swanson Flo

Founded in 1960, Swanson Flo has long maintained our position as an industry leader in process automation with unmatched project success leveraging industry preferred products and services.

Our mission is to provide innovative process control solutions for engineers, managers and maintenance professionals through quality equipment and experienced application engineering. These efforts combined with excellent aftermarket service yield reduced operating costs and improved production. Visit http://www.swansonflo.com or call 800-288-7926.