Fail-Safe Functionality in Actuators: A Line of Defense in Industrial Control

In critical process control applications across the chemical, oil and gas, water treatment, pharmaceutical, and power generation sectors, engineers and operators constantly consider one central question: "What happens when something goes wrong?" The concept of "fail-safe" lies at the heart of that question. In industrial actuators, fail-safe design protects people, equipment, and the environment when systems lose power or encounter a fault.

A fail-safe actuator ensures that a valve or damper moves to a predetermined, safe position during a failure event. This position might be open, closed, or somewhere between—whatever best minimizes risk for the specific application. In a chemical plant, for example, a valve that isolates a toxic chemical must shut completely if power is lost. In a cooling system at a power station, a valve might need to open fully to keep temperatures under control during an emergency. Engineers design these responses in advance based on safety studies, process requirements, and industry regulations.

Unlike standard actuators that stop moving or hold their last position when power or signal disappears, fail-safe actuators rely on mechanical or stored-energy systems—typically springs or capacitors—to drive the actuator to its safe state. Spring-return pneumatic actuators remain popular, using compressed air during regular operation and releasing stored spring energy to move the valve when the air supply or control signal fails. Electric fail-safe actuators often store energy in supercapacitors or battery systems to complete the fail-safe stroke when the power source vanishes.

These mechanisms don't just protect equipment; they actively prevent disaster. In oil and gas pipelines, fail-safe valves can shut off flow to contain leaks or explosions. Water treatment facilities might divert or isolate flow to prevent contamination. Pharmaceutical manufacturers use fail-safe actuators to maintain cleanroom integrity or safeguard precise mixing conditions. Every sector applies the principle differently, but the goal remains: respond instantly and predictably in the face of failure.

Designing a fail-safe system requires more than just choosing the proper actuator. Engineers must consider the entire control loop, the speed and force of valve closure, environmental conditions, and how often the actuator cycles. Maintenance teams also need easy ways to test and verify the fail-safe action without disrupting regular operations.

Ultimately, fail-safe actuators deliver more than just mechanical motion. They offer confidence. They help operators sleep at night, knowing that the process won't spin out of control even if the worst happens—be it a blackout, a signal failure, or a system fault. That assurance makes all the difference in high-stakes environments where seconds matter, and consequences ripple far beyond the plant walls.

UniTorq Actuators and Controls
2150 Boggs Road, Suite 410
Duluth, GA 30096
https://unitorq.com
Phone: (770) 446-7074
Fax: (770) 447-1825

Critical Factors in Proper Pneumatic Valve Actuator Sizing

Properly sizing a pneumatic valve actuator is essential for reliable and safe valve operation in industrial environments. It involves carefully analyzing the valve’s torque requirements, actuator characteristics, and the conditions under which the system will function.

The first step is determining exactly how much torque the valve requires. Valve manufacturers typically specify torque ratings that detail the force needed to open and close the valve under normal operating conditions. However, these torque values can change depending on factors like the valve design, the fluid or gas passing through it, and the pressures and temperatures involved. For instance, metal-seated butterfly valves usually require higher torque initially to break away from their seats but less force once they begin moving. In contrast, ball valves often need more consistent torque throughout their movement.

Once the valve’s torque requirements are determined, it’s essential to include an appropriate safety margin to account for variations or unexpected conditions. A standard industry practice is to add around 25% to the highest torque requirement. This extra margin ensures the actuator can handle unforeseen situations like the buildup of deposits within the valve or temperature extremes, which can increase torque demands beyond normal operating conditions.

Next, selecting the correct actuator type is essential. Pneumatic actuators come primarily in two varieties: rack-and-pinion and scotch yoke designs. Rack-and-pinion actuators offer consistent torque throughout their stroke, making them ideal for valves requiring uniform torque application. Scotch yoke actuators, meanwhile, produce higher torque at the start and end of their stroke. This characteristic makes them particularly suited to valves requiring significant force to break open or securely close.

Another critical factor is the available air supply pressure, which directly impacts how much torque an actuator can generate. It is vital to confirm that the actuator can deliver the necessary torque at the lowest expected air pressure. If the air supply pressure drops below expected levels, the actuator may not produce sufficient torque, potentially leading to operational issues. Always verify actuator torque output at minimum air pressure against the valve’s torque needs, including the safety margin.

Additionally, defining any fail-safe requirements early in the selection process is essential. Depending on the application, valves may need to fail in a specific position, either open, closed, or remain stationary upon loss of air pressure. Single-acting actuators, which use internal springs, automatically return to a predetermined position when the air supply is lost, making them ideal for applications requiring a defined fail-safe condition. Double-acting actuators, however, rely entirely on air pressure for both opening and closing movements, causing them to remain wherever they happen to be when pressure fails.

Finally, after thoroughly evaluating all these factors—valve torque requirements, actuator type, available air pressure, and fail-safe positions—you can confidently choose an actuator model. Manufacturer-provided actuator performance charts are valuable tools at this stage. These charts display torque output at various air pressures, helping match the actuator capabilities directly to your calculated torque requirements.

Selecting the right pneumatic valve actuator requires a methodical approach to ensure both performance and safety. When evaluating actuator options, carefully assess torque requirements, operating conditions, and fail-safe needs while consulting manufacturer specifications throughout the process.

Remember that proper sizing directly impacts system reliability, efficiency, and workplace safety. All pneumatic actuator specifications should undergo expert review prior to installation to verify compatibility with your specific application and compliance with relevant safety standards.

UniTorq
https://unitorq.com
770-446-7074

Innovative Valve Automation: UniTorq’s Cutting-Edge Actuators and Control Solutions

UniTorq Actuators and Controls drives innovation in valve automation. The company stands out by designing and manufacturing a wide range of actuators, limit switches, and valve positioners that meet the toughest demands in industrial and commercial applications. Based in Duluth, GA, UniTorq has built a solid reputation over more than 25 years by putting quality, reliability, and customer service at the forefront of every project.

Actuator Products That Deliver

UniTorq engineers design pneumatic actuators that respond quickly and precisely to production needs. Their rack and pinion and scotch-yoke designs deliver robust performance and durability. Customers enjoy actuators that halt directly at the pinion, a feature that boosts accuracy and minimizes wear. In addition, UniTorq’s electric actuators pack a compact, efficient design into every product. These electric units offer reliable motion control in environments where space is at a premium.

The company continuously innovates its product line to meet ever-changing industry requirements. For example, the new M-Series actuators represent a leap forward in design and performance. UniTorq engineers adjust travel stops with precision, provide enhanced tooth engagement, and incorporate a unique “top hat” thrust bearing. These design elements ensure consistent torque output and extend the life of critical components.

Limit Switches That Enhance Safety and Control

UniTorq features a specialized line of limit switches marketed under the SeniTec brand. These switches serve as vital position indicators that help maintain safe and reliable valve operation. Customers in high-demand industries rely on these devices to monitor valve position and provide early alerts if a valve fails to reach its designated position. UniTorq tailors these solutions to a variety of applications, ensuring that every installation meets strict performance and safety standards.

Valve Positioners That Optimize Automation

UniTorq designs valve positioners to work hand-in-hand with its actuators. The company offers both electro-pneumatic and digital valve positioners that convert control signals into precise mechanical movement. In operation, these positioners quickly adjust valve positions to match a 4–20 mA signal or another control input. This precision gives industries the confidence that process fluids will flow correctly, which is essential in chemical processing, water treatment, power generation, and oil and gas operations.

The transition to digital valve positioners further improves accuracy. Digital systems offer advanced diagnostics and enhanced communication capabilities, helping operators monitor equipment health and maintain system integrity. Whether customers require traditional electro-pneumatic positioners or the latest digital technology, UniTorq provides solutions that optimize performance and reduce downtime.

Serving Major Industries with Integrated Solutions

UniTorq tackles challenges in industries where valve automation remains critical. The company serves sectors like oil and gas, chemical processing, water treatment, power generation, and food and beverage production. Each industry benefits from UniTorq’s focus on durability and reliability. For instance, in harsh chemical environments, stainless steel body pneumatic actuators stand up to corrosion and reduce maintenance costs. In water treatment and power generation, rapid actuator response and precise valve positioning help maintain process control and safety.

UniTorq builds every product with an emphasis on quality management. The company adheres to ISO 9001:2015 standards, a testament to its commitment to continuous improvement and customer satisfaction. Customers trust UniTorq not only for innovative design but also for dependable service, prompt support, and competitive pricing.

A Company That Puts Customers First

UniTorq proves that success comes from more than just a quality product. The company prioritizes craftsmanship and service, tailoring solutions to each customer’s unique challenges. UniTorq’s experienced support team guides customers through every step—from product selection and installation to ongoing project support. This customer-first approach transforms one-time buyers into long-term partners, reinforcing UniTorq’s position as a trusted advisor in valve automation.

By consistently delivering intelligent, integrated solutions for valve automation, UniTorq Actuators and Controls continues to set new standards in the industry. Customers count on the company’s actuators, limit switches, and valve positioners to optimize their processes, reduce downtime, and maintain safe, efficient operations every day.

UniTorq Actuators and Controls  

2150 Boggs Road, Suite 410  

Duluth, GA 30096  

Phone: 770-446-7074  

Email: info@unitorq.com

https://unitorq.com

UniTorq’s Secret to 30+ Years of Success: Trust, Service, and Value

Longevity in business often stems from a simple but powerful equation: quality products, exceptional service, and competitive pricing. At UniTorq Actuators and Controls in Duluth, Georgia, this equation has fueled more than three decades of success in the manufacturing and supply of pneumatic and electric actuators, limit switches, and positioners. The company's ability to "stand the test of time" provides a compelling example of what it takes to thrive in a competitive industry.

UniTorq's reputation for delivering high-quality products did not happen by accident. From day one, the company has prioritized craftsmanship and reliability. Each actuator, limit switch, and positioner reflects a commitment to durability and performance, meeting the rigorous demands of industrial applications. Customers know they can rely on UniTorq products to work seamlessly, even in the harshest conditions. That trust builds loyalty and sets the company apart from competitors who might cut corners in the name of lower costs.

But quality alone does not guarantee longevity. UniTorq couples its manufacturing excellence with a laser focus on customer service. The team understands that every customer has unique challenges, and they respond with tailored solutions, rapid response times, and genuine care. This level of service turns one-time buyers into lifelong partners and positions UniTorq as more than just a supplier—it becomes a trusted advisor.

Competitive pricing completes the equation. While some equate high quality with high cost, UniTorq strikes a balance. The company's ability to deliver superior products at fair prices allows its customers to maximize value without sacrificing performance. This approach ensures that clients view UniTorq not just as a vendor but as an essential part of their success.

Thirty years of growth and customer loyalty don't just happen. They require vision, effort, and an unwavering commitment to doing things correctly. UniTorq's story reminds us that longevity isn't a coincidence—it's the natural outcome of prioritizing quality, service, and value above all else. For those who partner with UniTorq, the benefits of that philosophy are apparent every day.

UNITORQ
2150 Boggs Road
Suite 410
Duluth, GA 30096
https://unitorq.com
Phone: 770-446-7074
Fax: 770-447-1825

Merry Christmas and Happy New Year from UniTorq

As we close out 2024, all of us at UniTorq want to express our sincere gratitude for your trust and support throughout the year. Your partnership has been a cornerstone of our success, and we’re thankful for the opportunity to work alongside such valued customers, committed vendors, and dedicated team members.

Every project and milestone this year has reminded us how fortunate we are to be part of this incredible community. Your collaboration and confidence in us have made a lasting impact, and we sincerely appreciate your role in our success.

We hope you enjoy peace, joy, and meaningful time with family and friends during this holiday season. May the New Year bring good health, new opportunities, and continued success for you and your loved ones.

Looking ahead to 2025, we’re excited about what we can accomplish together. Your continued partnership inspires us to keep growing, innovating, and delivering our best.

From all of us at UniTorq, thank you for an outstanding 2024. Wishing you a wonderful holiday season and a happy, prosperous New Year!

Ensuring Reliable Valve Operation: The Role of Torque Safety Factors in Actuator Sizing

Pneumatic rack and pinion actuators are pivotal in automating industrial valves, enabling precise control over fluid flow in various processes. When engineers select these actuators for specific valve applications, they must ensure they can deliver sufficient torque to operate the valve under all expected conditions. This requirement leads to incorporating a torque safety factor in the sizing calculations. Understanding why this safety factor is essential involves examining the variables that affect valve torque requirements and the operational reliability of the actuator-valve system.

The Critical Role of Proper Actuator Sizing

Actuator sizing is not merely matching nominal torque values between the actuator and the valve. Valves often experience conditions that can significantly increase the torque required to open or close them. If the actuator cannot provide the necessary torque under these conditions, the valve may fail to operate as intended, leading to process interruptions, safety hazards, or equipment damage. Therefore, engineers must account for various factors influencing torque requirements to ensure reliable and safe valve operation.

Factors Influencing Valve Torque Requirements

Several factors can cause the torque required to operate a valve to exceed the nominal values provided by the manufacturer:

• Friction and Wear: Over time, valves can experience increased friction due to wear, corrosion, or the accumulation of deposits on sealing surfaces. This friction directly translates to higher torque requirements. For instance, sediment buildup in a butterfly valve can make it harder to turn, necessitating more torque from the actuator.
• Temperature Variations: Temperature changes can affect the materials of both the valve and the actuator. Thermal expansion or contraction can alter clearances and increase friction. Additionally, temperature changes can affect the viscosity of the process fluid, making it harder to move the valve.
• Pressure Fluctuations: The differential pressure across a valve influences the torque needed to operate it. Unexpected increases in upstream or downstream pressure can create additional forces that the actuator must overcome. For example, in a ball valve, higher pressure can increase the seating force, thus requiring more torque to unseat the ball.
• Valve Seat Aging: The degradation of valve seats over time can lead to increased torque requirements. Aging seats may harden, lose elasticity, or become damaged, making the valve harder to operate.
• Unanticipated Loads: External factors such as pipeline stresses, misalignment, or mechanical interference can impose additional loads on the valve stem, increasing the torque needed for operation.
• Supply Pressure Variations: Pneumatic actuators rely on a supply of compressed air at a specific pressure. Fluctuations in this supply pressure can reduce the actuator's output torque. For instance, if the air supply drops below the design pressure, the actuator may not produce enough torque to operate the valve.

The Justification for a Torque Safety Factor

Given the many variables that can increase the torque required to operate a valve, engineers incorporate a torque safety factor into the actuator sizing process. This safety factor is a multiplier, usually expressed as a percentage, applied to the nominal valve torque to ensure the actuator can handle the maximum expected torque under all conditions.

The torque safety factor accounts for the following:

• Operational Uncertainties: It compensates for unknown or unpredictable factors that may affect valve torque requirements during the valve's service life.
• Manufacturing Variances: This section considers tolerances and variations in the manufacturing of valves and actuators, which can affect performance.
• Maintenance Practices: It allows for less-than-ideal maintenance conditions, such as valves not being serviced as regularly as required.
• Extreme Conditions: It ensures that the actuator can operate the valve during extreme conditions, such as emergency shutdowns or start-ups, where conditions may not be typical.

By applying a torque safety factor, engineers build a margin of safety that enhances the reliability and longevity of the valve-actuator assembly. This practice helps prevent operational failures, reduces downtime, and maintains safety standards within the industrial facility.

Incorporating a torque safety factor when sizing pneumatic rack and pinion actuators for industrial valves is a critical engineering practice. It accounts for the myriad factors that can increase torque requirements beyond nominal values and ensures that actuators can reliably operate valves under all anticipated conditions. By doing so, engineers safeguard against operational failures, enhance system reliability, and uphold safety in industrial processes.

UNITORQ
2150 Boggs Road
Suite 410
Duluth, GA 30096
https://unitorq.com
Phone: 770-446-7074
Fax: 770-447-1825

Advantages of Stainless Steel Body Pneumatic Rack & Pinion Actuators

Stainless steel body pneumatic rack and pinion actuators have gained significant popularity in various industrial sectors due to their robust construction and reliable performance by combining the toughness of stainless steel with the efficiency of pneumatic operation, these actuators offer several advantages that make them suitable for demanding applications.

One of these actuators' primary advantages is their exceptional resistance to corrosion. Stainless steel protects against corrosion from exposure to harsh chemicals, moisture, and extreme temperatures. This quality makes these actuators ideal for chemical processing, pharmaceuticals, and food and beverage production, where equipment frequently contacts corrosive substances or requires regular washdowns.

Durability represents another significant benefit of these actuators. The stainless steel construction ensures long-term operational reliability, reducing the need for frequent maintenance or replacement. This durability translates into lower operational costs and increased productivity as minimal equipment downtime occurs. In industries where continuous operation remains critical, such as oil and gas or power generation, the reliability of stainless steel actuators becomes an invaluable asset.

These actuators also offer high performance in terms of torque output and speed. The rack and pinion mechanism efficiently converts the linear motion of the pneumatic piston into rotational motion, providing precise control over valve positions. This precision is crucial in applications that require accurate flow control, such as water treatment facilities or chemical dosing systems.

The hygienic properties of stainless steel make these actuators suitable for use in industries with strict sanitary requirements. Equipment in the food and beverage industry must adhere to stringent hygiene standards to prevent contamination. Operators can easily clean stainless steel actuators, which do not harbor bacteria, ensuring compliance with health and safety regulations. Similarly, in pharmaceutical manufacturing, maintaining sterile conditions is essential; stainless steel equipment supports this necessity.

Industries operating in extreme temperatures also benefit from stainless steel body pneumatic rack and pinion actuators. Stainless steel retains its mechanical properties over a wide temperature range, making these actuators suitable for cryogenic applications or high-temperature processes. For example, these actuators maintain consistent performance in power plants or refineries, where temperatures can fluctuate significantly.

Stainless steel body pneumatic rack and pinion actuators offer a combination of corrosion resistance, durability, precision, and safety. Industries that benefit most from these actuators include chemical processing, pharmaceuticals, food and beverage production, oil and gas, water treatment, and power generation. The unique advantages of stainless steel construction make these actuators reliable for applications that demand high performance and resilience in challenging environments. By investing in stainless steel actuators, industries can enhance operational efficiency, ensure compliance with regulatory standards, and achieve long-term cost savings through reduced maintenance and downtime.

UNITORQ

2150 Boggs Road

Suite 410

Duluth, GA 30096

https://unitorq.com

Phone: 770-446-7074

Fax: 770-447-1825