Views: 0 Author: J-VALVES Publish Time: 2025-06-11 Origin: Site
Understanding Bellows Globe Valves
Bellows globe valves combine the benefits of a bellows seal with the precise flow control capabilities of a globe valve. The bellows design provides a leak-tight seal, protecting the valve stem from corrosive media and ensuring long-term reliability. The globe valve mechanism allows for precise control over fluid flow, making it ideal for applications requiring accurate regulation.
Key Components of Bellows Globe Valves
• Valve Body: The main structure that houses all internal components.
• Bellows Assembly: Provides a leak-tight seal and protects the valve stem from corrosive media.
• Globe Valve Mechanism: Controls the flow of fluid through the valve.
• Valve Stem: Connects the valve mechanism to the actuator or handwheel.
• Valve Seat: Provides a tight seal when the valve is closed.
• Valve Plug: Opens and closes the flow path.
• Actuator: Provides the torque to operate the valve.
Sealing Requirements in Extreme Conditions
In high-temperature applications, the bellows and sealing materials must be capable of withstanding elevated temperatures without degradation. Common materials used for bellows in high-temperature applications include:
• Inconel: A high-performance alloy known for its excellent strength and corrosion resistance at high temperatures.
• Hastelloy: Another high-performance alloy that maintains its mechanical properties at extreme temperatures.
For high-pressure applications, the valve body and internal components must be designed to withstand significant pressures without deformation or failure. Bellows globe valves are available in various pressure ratings, including:
• Class 150 (PN16): Suitable for low-pressure applications.
• Class 300 (PN20): Ideal for moderate-pressure applications.
• Class 600 (PN40): Suitable for high-pressure applications.
• Class 900 (PN63): For very high-pressure applications.
• Class 1500 (PN100): For extremely high-pressure applications.
• Class 2500 (PN160): For ultra-high-pressure applications.
When dealing with corrosive media, the choice of materials is crucial for ensuring long-term reliability. Bellows globe valves are available in a variety of corrosion-resistant materials, including:
• Stainless Steel (316L): Provides excellent corrosion resistance and is suitable for a wide range of corrosive media.
• Duplex Steel: Offers superior corrosion resistance and strength, making it ideal for aggressive environments.
• Super Duplex Steel: Provides even greater corrosion resistance and strength compared to duplex steel.
Bellows globe valves are designed to provide precise flow control, making them ideal for applications requiring accurate regulation. The globe valve mechanism allows for fine-tuning of fluid flow, ensuring optimal process performance.
The flow characteristics of bellows globe valves can be tailored to meet specific application requirements. Common flow characteristics include:
• Linear: Provides a linear relationship between valve position and flow rate, making it suitable for applications requiring proportional control.
• Equal Percentage: Provides a logarithmic relationship between valve position and flow rate, making it ideal for applications requiring precise control over a wide range of flow rates.
Bellows globe valves are available with a variety of actuation options to suit different operating conditions and control requirements:
• Manual Actuation: Suitable for applications where manual control is preferred.
• Pneumatic Actuation: Provides precise control and is suitable for applications requiring remote operation.
• Electric Actuation: Offers precise control and is ideal for applications requiring integration with automated control systems.
• Hydraulic Actuation: Provides high torque and is suitable for applications requiring heavy-duty operation.
