The Increasingly Important Role of 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

What Are Cryogenic Ball Valves?

Cryogenic Ball Valve (Flowserve Worcester)

Cryogenic ball valves are high-performance shutoff valves for intermittent and continuous flow applications with temperatures to -425°F. They are used on tough applications involving all types of cryogens, such as oxygen, hydrogen, methane, ammonia, nitrogen, fluorine, LNG and deuterium.

Cryogenic ball valves include unique features to ensure safety and performance in cryogenic applications. Central to the cryogenic design is a rugged, one-piece, pressure safe stem with a Polyfill thrust bearing and stainless steel split ring. It provides design safety and low operational torque. Polyfill seats give you tight shutoff throughout the temperature range. With an orientation-controlled stem/ball connection and an upstream hole in the ball, you get positive overpressure protection.

Summary of specialized design features:

Brass Cryogenic Ball Valve
(Flowserve Worcester)

• Positive Ball Cavity Relief – An upstream relief hole in the ball prevents dangerous overpressure due to thermal expansion. On extended stem valves through 2", a one-piece stem with alignment pin assures proper orientation of the ball.
• Pressure Safe Stem – Both one-piece and two-piece, assembled inside-the-body stems are safe from blowout and are supported with Polyfill® thrust washers.
• Zero Leak Packing – Belleville live-loaded TFE packing rings and stem centering followers assure zero leakage through the toughest, high-cycle applications.
• Effective Bonnet Extensions – The stem extensions of cryogenic valves conform to standard industrial practices. That means wall thickness and lengths that keep heat transfer down, the packing frost-free, operational torques low, and actuators solidly supported.
• High-Performance/Low-Thermal Stress – The special “part compatibility” design of valve parts, Polyfill seats and body seals assure tight shutoff, zero body leakage and low torque through large thermal excursions from ambient to -425°F.

Cryogenic valves are normally available in four body configuration, in either stainless steel or brass:

1. Three-piece construction - makes it easy to install, versatile in application and simple to maintain.
2. The cryogenic diverter valve - accepts media through the bottom inlet port and directs it to one of two side ports.
3. The wafer design - a flangeless cryogenic valve that mounts between ANSI Class 150 or 300 flanges.
4. A flanged design - has a body cast with ANSI Class 150 flanges.

Application for cryogenic ball valves:

• Over-the-Road LNG-LPG Trailers
• Terminal Unloading Stations
• High-Purity Cryogenic/Gas Systems
• LNG Storage and Distribution
• CO2 and Nitrogen Injection for Enhanced Oil Recovery
• Over-the-Road CO2, LNG, Food Carriers
• Petroleum Refining Unleaded Gasoline (Gas Treatment Skids)
• Lyophilization Systems
• Air Separation Plants
• Liquid and Gaseous Oxygen
• Inerting and Heat Treatment

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

Understanding Industrial Rack and Pinion Valve Actuators

Basic concept of
rack and pinion gear.

Valves are essential to industries which constitute the backbone of the modern world. The prevalence of valves in engineering, mechanics, and science demands that each individual valve performs to a certain standard. Just as the valve itself is a key component of a larger system, the valve actuator is as important to the valve as the valve is to the industry in which it functions. Actuators are powered mechanisms that position valves between open and closed states.

Pneumatic rack and pinion actuators utilize air pressure as the motive force which changes the position of a valve.  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. See the animation above (provided by Wikipedia) below for a visual understanding.

This short video introduces the basic parts and operation of rack and pinion valve actuators to anyone unfamiliar with the device.

Visit http://www.swansonflo.com to learn more about industrial valves, valve actuators, and valve automation.