Pneumatic control valves are widely applied in various industrial conditions due to their diverse structures, precise control, and strong adaptability. Below are their main applicable conditions and characteristics:
1. High Pressure Differential and Flashing/Cavitation Conditions
• Multi-stage Pressure Reduction Design: Suitable for high-pressure differential environments, it gradually reduces pressure through multi-stage pressure reduction valve cages (sleeves), preventing flashing and cavitation phenomena and extending valve lifespan.
• Cavitation Resistance: Special trim structures (such as multi-hole sleeves) can reduce fluid noise and minimize damage to valve internals caused by cavitation.
2. Extreme High/Low Temperature Environments
• High-Temperature Type: Utilizes metal sealing ring structures, suitable for temperatures up to 550°C (e.g., high-temperature steam, hot oil systems).
• Low-Temperature Type: Features an extended bonnet design, suitable for cryogenic media at -196°C (e.g., liquefied natural gas, liquid nitrogen).
3. Corrosive Media
• Fluorine-Lined Valves: Used for strongly acidic, alkaline, and other corrosive media (e.g., hydrochloric acid, sulfuric acid), lined with materials such as PTFE and PFA.
• Stainless Steel/Alloy Valve Bodies: Such as 316L and HC276, suitable for corrosive fluids in the chemical and pharmaceutical industries.
4. High-Precision Flow Control
• Equal Percentage/Linear Flow Characteristics: Suitable for applications requiring precise regulation (e.g., chemical reactors, heat exchangers).
• High Rangeability (30:1~50:1): Suitable for regulating a wide range of flow rates.
5. Special Industrial Applications
• Petrochemical Industry: High-pressure, high-temperature, and corrosive media (e.g., refining, cracking units).
• Power Industry: Steam regulation (e.g., boiler feedwater, turbine control).
• Water Treatment/Environmental Protection: Wastewater treatment, acid-base neutralization, and other conditions.
6. Other Special Requirements
• Low Leakage Requirements: Soft-seated valve seats (e.g., PTFE) can achieve ANSI B16.104 Class VI sealing, suitable for toxic or hazardous media.
• Explosion-Proof Environments: Explosion-proof actuators can be used in flammable and explosive conditions (e.g., oil and gas pipelines).
Summary
Pneumatic control valves are suitable for a wide range of conditions. When selecting a valve, it is essential to consider media characteristics (corrosiveness, temperature, pressure), flow control accuracy, and environmental requirements (explosion-proof, low noise). Specific models (such as cage-guided, multi-stage pressure reduction, fluorine-lined types) should be matched according to actual conditions.