Comparing Industrial Butterfly Valves: Rubber Lined, High Performance, and Offset Designs

Butterfly valves play a vital role in industrial fluid control systems, efficiently regulating flow across a wide range of applications. Rubber-Lined (General-Purpose) Butterfly Valves—and High-Performance Butterfly Valves (including Double and Triple Offset designs) stand out due to their unique designs and specific uses. Understanding the differences in valve style, construction, and application is crucial for selecting the most suitable valve for a given industrial need.

Rubber-Lined (General-Purpose) Butterfly Valves feature a straightforward, robust design ideal for low-pressure and low-temperature environments. In these valves, the stem is centered in the middle of the disc and seat, meaning the disc remains in constant contact with the seat throughout its operation. The valves consist of a disc mounted on a rotating shaft within a rubber-lined body, where the rubber lining acts as both the seat and the seal, ensuring tight shut-off when the disc closes. While this design offers simplicity and cost-effectiveness, it can lead to increased wear under higher pressures and temperatures due to the constant contact between the disc and seat. Industries such as HVAC, water treatment, and general manufacturing frequently employ rubber-lined butterfly valves due to their reliability and economical nature, especially in applications involving non-corrosive fluids at low pressures and temperatures.

In contrast, High-Performance Butterfly Valves are engineered for more demanding applications involving higher pressures and temperatures. These valves often incorporate advanced materials like stainless steel or specialized alloys for the disc and seat, enabling them to handle steam, gases, and corrosive chemicals. High-performance designs include Double Offset and Triple Offset Butterfly Valves, each offering enhanced capabilities for specific industrial needs.

Double Offset Butterfly Valves incorporate two distinct offsets: one from the centerline of the pipe and the second from the centerline of the seat cone. This design minimizes rubbing between the disc and seat during operation, reducing wear and enhancing seal longevity. The reduced friction allows these valves to operate effectively in higher pressure and temperature conditions than zero offset valves. Industries requiring reliable performance and extended service life under challenging conditions often utilize double offset designs.

Triple Offset Butterfly Valves add a third offset by designing the sealing components with a conical profile. This feature ensures that the disc contacts the seat only at the final point of closure, virtually eliminating wear and providing a torque-seated, zero-leakage valve. Constructed with metal-to-metal sealing surfaces, triple offset valves can withstand extreme temperatures and pressures. Industries such as petrochemical, power generation, and refining favor these valves for critical applications where safety and reliability are paramount.

Comparing these valves reveals key differences in design and operational capabilities. Rubber-lined valves, with their concentric design and elastomeric lining, offer simplicity and cost-effectiveness for general-purpose use but are limited to lower pressure and temperature applications. High-Performance Butterfly Valves, including double and triple offset designs, enhance performance for moderate to high-pressure systems thanks to their offset stems and improved sealing mechanisms.

Selecting the appropriate butterfly valve hinges on the application's specific requirements, including the type of fluid, pressure, temperature, and the necessity for tight shut-off. Rubber-lined butterfly valves present economical and effective solutions for general-purpose needs involving non-corrosive fluids at low pressures and temperatures. Conversely, High-Performance Butterfly Valves with double and triple offset designs are better suited for challenging environments where reliability and longevity are essential under higher pressures and temperatures.

Understanding the nuances of each valve type ensures optimal performance, safety, and cost-effectiveness in industrial fluid control systems. Engineers and operators can make informed decisions that enhance system efficiency and reliability by carefully considering valve style, construction, and application requirements.

Classic Controls  

+1 863-644-3642  

https://classiccontrols.com

Revolutionizing Process Management: The Role of Digitalization in Enhancing Industrial Valve and Instrumentation Operations

Factory digitalization, or Industry 4.0 or the Fourth Industrial Revolution, is characterized by integrating digital technologies into manufacturing processes. Key technologies include:

• Internet of Things (IoT): Sensors and devices interconnected over the internet, providing real-time data.
• Big Data Analytics: Analyzing large volumes of data for insights to optimize processes.
• Artificial Intelligence and Machine Learning: Intelligent systems that learn from data and improve decision-making.
• Cloud Computing: Remote servers store and process data, providing scalability and flexibility.
• Cyber-Physical Systems (CPS): Integration of physical processes with computer-based algorithms.
• Additive Manufacturing: 3D printing technologies for creating components.

Impact on Industrial Valves

Industrial valves are critical for controlling the flow of liquids and gases in various industrial processes. Digitalization has led to the development of 'smart valves' with embedded sensors and actuators. These advancements allow for:

• Real-time Monitoring: Enhanced capabilities for monitoring valve conditions, predicting maintenance needs, and avoiding unscheduled downtimes.
• Automated Control: Valves can automatically adjust based on real-time data, optimizing flow and reducing human intervention.
• Predictive Maintenance: AI algorithms analyze data to predict valve failures before they occur.
• Energy Efficiency: Optimizing valve operations to reduce energy consumption in processes.

Changes in Process Control Instrumentation

Process control instrumentation has also undergone significant changes due to digitalization. Flow meters, pressure gauges, and temperature sensors are now smarter and more interconnected. The impacts include:

• Enhanced Data Accuracy: Digital instruments provide more precise and reliable data.
• Remote Monitoring and Control: Operators can monitor and adjust processes from remote locations, enhancing flexibility and safety.
• Integration with Control Systems: Seamless integration with advanced control systems for more efficient process management.
• Predictive Analytics: Use data analytics to foresee potential issues and optimize process parameters.

Challenges and Opportunities

While factory digitalization offers numerous benefits, it also presents challenges:

• Cybersecurity: Increased digitalization heightens the risk of cyber attacks.
• Skilled Workforce: There's a growing need for a workforce skilled in digital technologies.
• Investment Costs: Initial investment in digital technologies can be high.

However, the opportunities are substantial:

• Increased Efficiency and Productivity: Automation and data analytics lead to more efficient operations.
• Enhanced Quality Control: Better monitoring and control improve product quality.
• Sustainability: Digitalization can lead to more sustainable manufacturing practices.

Conclusion

Factory digitalization is reshaping the industrial landscape, including industrial valves and process control instrumentation. By embracing these changes, manufacturers can gain significant efficiency, quality, and competitiveness advantages. However, they must also navigate challenges such as cybersecurity and needing skilled personnel. The future of manufacturing lies in successfully integrating these digital technologies into everyday industrial practices.

Classic Controls
+1 863-644-3642
https://classiccontrols.com

Fluid Processes - When A Butterfly Valve Is The Best Choice

High performance butterfly valve with actuator
Image courtesy ABZ Valve

Industrial process control valves are available in uncountable combinations of materials, types, and configurations. An initial step of the selection procedure for a valve application should be choosing the valve type, thus narrowing the selection field to a more manageable level. Valve "types" can generally be classified by the closing mechanism of the valve.

A butterfly valve has a disc that is positioned in the fluid flow path. In the most common form of butterfly valve, the disc rotates around a central axis, the stem, through a 90 degree arc from a position parallel to the flow direction (open) to perpendicular (closed). A variety of materials are used in the valve body construction, and it is common to line the valve with another material to provide special properties accommodating particular process media.

What attributes might make a butterfly valve a beneficial selection over another valve type?

• The closure arrangement allows for a comparatively small size and weight. This can reduce the cost, space, and support requirements for the valve assembly.
• Generally low torque requirements for valve operation allow for manual operation, or automation with an array of electric, pneumatic, or hydraulic actuators.
• Low pressure drop associated with the closure mechanism. The disc in the flow path is generally thin. In the fully open position, the disc presents its narrow edge to the direction of flow.
• Quarter turn operation allows for fast valve operation.
• Some throttling capability is provided at partially open positions.
• Small parts count, low maintenance requirements.

What may be some reasons to consider alternate valve types?

• Butterfly valve throttling capability is generally limited to low pressure drop applications
• Cavitation can be a concern.
• Some sources mention the possibility of choked flow as a concern under certain conditions.

Butterfly valves, like other valve types, have applications where they outperform. Careful consideration and consultation with a valve expert is a first step toward making a good selection. Combine your process know-how with the product application expertise of a professional sales engineer to produce the best solutions to your process control challenges.

Resilient Seated Butterfly Valves from Classic Controls, Inc.

Valve Control Monitor Adapts to Wide Range of Actuators

Valve monitor control mounted using cast NAMUR bracket
Courtesy Westlock Controls

Combining control components from various manufacturers can sometimes facilitate the most effective or desirable solution to a process control challenge. This can certainly be true when configuring a control valve installation. Getting the feature set and packaging that best fit the application requirements can yield benefits throughout the useful life of the equipment.

Westlock Controls, manufacturer of valve control monitors, provides a convenient mounting bracket that adapts the installation of their valve control monitors to actuators employing NAMUR mounting patterns. The cast stainless steel bracket is provided in one of three available mounting kits, each complete with all necessary hardware.

More detail about the adapter bracket is found in the datasheet included below. For more information, share your control valve project requirements and challenges with process control valve experts, combining your own process knowledge and experience with their product application expertise to develop effective solutions.

Stainless Steel Cast NAMUR Mounting Bracket from Classic Controls, Inc.

Severe Service Valve Applications

Industrial valve for severe service

Industrial process control applications can be associated with some very stringent and challenging performance requirements for the physical equipment and components that are part of the process chain. In fluid based operations, the control and shutoff valves can be a significant impact point of extreme fluid conditions, requiring careful design and selection consideration to assure proper performance and safety levels are predictably maintained.

Industrial valves that are intended for application at the extremes are generally referred to as severe service valves. While there are plenty of published and accepted standards for industrial valves, one does not exist to precisely define a severe service valve. There is, however, some movement toward the development of severe service standards in some industry segments.

So, how do you know when to focus valve selection activities on severe service valves, as opposed to general purpose valves? There are a number of basic criteria that might point you in that direction:

• Very extreme media or environmental temperature
• High pressure drop operation that may cause cavitation
• Rapid and extreme changes to inlet pressure
• Certain types or amounts of solids contained in the fluid
• High number of mechanical operations
• Thermal cycling

Certainly, any of these criteria might be found in an application serviceable by a general purpose valve, but their presence should be an indicator that a closer assessment of the fluid conditions and commensurate valve requirements is in order. The key element for a process stakeholder is to recognize when conditions are in evidence that might overrun the capabilities of a general purpose valve, leading to premature failure in control performance or catastrophic failure that produces an unsafe condition. Once the possibility of a severe service condition is identified, a careful analysis of the possible operating conditions will reveal the performance requirements for the valve.

There are numerous manufacturers of severe service valves, each seeming to concentrate on a particular niche. The oil and gas industry presents numerous applications for specially designed valves, as do other industries.

You can always get more information, or discuss your special requirements, with a product application specialist. They have access to technical resources that can help with selecting the right valve configuration to meet your severe service applications.

Going International With Your Design - Solenoid Operated Valves

Industrial Solenoid Valve
Emerson - ASCO

It's no secret to you, Engineer, that the world is densely populated with standards and approvals. No matter where you live or work, the process equipment designs that flow from your workstation, your team, your company, are more likely than ever to end up on foreign shores.

Solenoid operated valves are ubiquitous, even a little mundane in their apparent simplicity, but still require expertise for proper specification and application. The jurisdictional requirements for a valve assembly applied in the same manner can vary from one country to another. This can be especially important when designing equipment or processes that may be installed in different parts of the world, such as United States and European Union production plants of a single company.

Fortunately, many manufacturers now provide valves with multiple approvals from around the world to facilitate the use of a single component across a wide geographic and jurisdictional range. Even with this accommodation, it is still the specifying engineer’s responsibility to select the correct valve, not only for the application, but for a regulatory environment that is populated with standards and approvals that can be difficult to coordinate with confidence. One prominent valve brand, ASCO, provides a white paper that delivers some insight into navigating this challenge, outlining an array of international approval agencies and providing a clear explanation of how T-codes (temperature codes) vary between US and EU agencies. The white paper is included below, a must-read for any engineer specifying or servicing solenoid valves.

Share your process control valve requirements and challenges with product application experts. Their expertise and your process knowledge, when combined, will deliver effective solutions.

Asco solenoid valve temperature code explanation whitepaper from Classic Controls, Inc.

High Performance Butterfly Valves Meet Special Application Challenges

High Performance
Butterfly Valve
ABZ Valve

Industrial process control applications can present stringent and challenging performance requirements for the physical equipment and components that comprise the process chain. The valves employed in fluid based operations need to be resistant to the impact of extreme fluid conditions, requiring careful design and selection consideration to assure proper performance and safety levels are maintained in a predictable way.

Industrial valves intended for extreme applications are generally referred to as severe service or high performance valves. While there are plenty of published and accepted standards for industrial valves, one does not exist to precisely define what constitutes a severe service valve.

So, how do you know when to focus valve selection activities on severe service or high performance valves, as opposed to those rated for general purpose? There are a number of basic criteria that might point you in that direction:

• Extreme media or environmental temperature or pressure
• High pressure drop operation that may cause cavitation
• Rapid or extreme changes to inlet pressure
• Certain types or amounts of solids contained in the fluid
• Corrosive media

Certainly, any of these criteria might be found in an application serviceable by a general purpose valve, but their presence should be an indicator that a closer assessment of the fluid conditions and commensurate valve requirements is in order. The key element for a process stakeholder is to recognize when conditions are contemplated that can exceed the capabilities of a general purpose valve, leading to premature failure in control performance or catastrophic failure that produces an unsafe condition. Once the possibility of an extreme or challenging condition is identified, a careful analysis of the range of operating conditions will reveal the valve performance requirements.

There are numerous manufacturers of severe service or high performance valves, each with specialized product offerings focusing on a particular performance niche. ABZ Valve manufactures high performance butterfly valves ranging from 2-48 inches and 150-600 psi. The valve design is ideal for manual or automated actuation, installed with a manual hand gear, electric actuator, or a pneumatic actuator. Seats are available as soft, metal, and fire safe, and body types include wafer, double flanged, and butt-welded. Construction materials include carbon steel and 316 stainless steel. A range of options and variants are available to customize the valve build to suit a replacement or new installation.

More information about the ABZ  Valve high performance offering is included below. You can always get more information and discuss your special requirements with a valve specialist. They have application experience and access to technical resources that can help with selecting the right valve components to meet your severe service and high performance applications.

Double Offset High Performance Butterfly Valves from Classic Controls, Inc.