What is Pneumatic Wafer Type Centerline Butterfly Valve
The pneumatic wafer-type centerline butterfly valve is composed of a pneumatic actuator and a wafer-type butterfly valve body. It uses compressed air to drive the butterfly plate to rotate (0-90 degrees range). The valve body has no built-in flange and is directly clamped between two pipe flanges by bolts to achieve a seal, thereby completing the automatic valve for cutting off or connecting pipeline media or regulating basic flow.
Structural Features
Core Structure: In this pneumatic wafer-type centerline butterfly valve, the valve stem axis, the center of the butterfly plate, and the center of the valve body are located at the same position. This design makes the valve structure simple, compact, and easy to manufacture.
Sealing Method: Soft sealing is commonly used, such as rubber-lined butterfly valves and PTFE-lined butterfly valves. The sealing principle utilizes elastic sealing materials such as rubber or PTFE. When the valve is closed, the butterfly plate compresses the sealing material, causing it to elastically deform and fill the gap between the butterfly plate and the valve body, thus achieving a good sealing effect.
Actuating Mechanism: Supports multiple actuation methods including manual, electric, and pneumatic, meeting the needs of different working conditions. The operating lever can rotate 360 degrees, making operation flexible and convenient. Opening and closing can be achieved with a 90° rotation. The operating torque is low, requiring minimal effort and is lightweight.
Performance Characteristics
Superior Sealing Performance: Utilizing an elastic sealing ring, the valve disc and seat have a large contact area, ensuring reliable sealing. In a fully sealed state, gas leakage is zero during testing.
High corrosion resistance: The valve body and disc are often made of stainless steel or corrosion-resistant materials, suitable for handling various media, including corrosive media.
Good regulating performance: The flow characteristics are nearly linear, providing excellent regulating performance, and can be used to regulate fluid flow and pressure.
Long service life: With tens of thousands of opening and closing tests, it ensures long-term stable operation.
Easy installation: Small and lightweight, easy to disassemble and maintain, and can be installed in any location, saving space.
Applications
Pneumatic wafer-type centerline butterfly valves are widely used in many fields such as petroleum, chemical, power, metallurgy, hydropower, mining, water treatment, shipbuilding, biofuel production, and food industry. For example:
Oil and gas industry: Commonly used in pipeline systems for transporting oil and natural gas, its excellent sealing performance and corrosion resistance allow it to adapt to complex chemical environments.
Power industry: Pneumatic wafer-type centerline butterfly valves are used to control the flow of power systems, ensuring the stability and safety of power transmission.
Metallurgical Industry: Used to control the flow of molten metal and gas; its high-temperature and corrosion-resistant properties make it perform excellently in high-temperature and corrosive environments.
Water Treatment and Seawater Desalination: Used to control water flow, ensuring the efficiency and quality of water treatment.
Selection Factors
Media Characteristics: Consider fluid type (gas, liquid, particulate/corrosive media, etc.), medium temperature, viscosity, corrosivity, etc.
Operating Pressure and Temperature Range: Determine the maximum operating pressure and temperature range. High-temperature media require metal-sealed butterfly valves; low-temperature media require attention to the low-temperature brittleness of the material.
Flow Control Requirements: Whether flow regulation is required, or if it is only used for on/off (switch type).
Structural Type: Select a center-line butterfly valve (suitable for low-pressure, normal-temperature applications without stringent sealing requirements), a double-eccentric butterfly valve (superior sealing performance compared to the center-line type, suitable for medium-pressure, medium-temperature conditions), or a triple-eccentric butterfly valve (metal-to-metal sealing surface, resistant to high temperature and pressure, suitable for harsh conditions) based on the operating conditions.
Connection methods: Clamp-on type is compact and suitable for space-constrained pipelines; flange type facilitates installation and disassembly, offers good sealing, and is suitable for high-pressure, large-diameter pipelines; welded type is used for high-pressure or special media.
Material selection: Valve body materials include cast iron (low pressure, normal temperature), carbon steel (medium and high pressure), and stainless steel (corrosive media); sealing materials include rubber (EPDM, NBR, etc., for non-corrosive media such as water and air), polytetrafluoroethylene (PTFE, corrosion-resistant, high-temperature resistant, suitable for chemical media), or metal seals (stainless steel, alloy, high-temperature and high-pressure resistant, used in triple-eccentric butterfly valves).
Nominal diameter and pressure rating: The nominal diameter must match the pipeline inner diameter to avoid excessive flow velocity leading to wear or noise; the pressure rating must be selected based on the system's maximum working pressure.
Operation methods: Manual operation is suitable for small-diameter valves or applications requiring infrequent operation; electric actuators are used for automated control or remote operation; pneumatic actuators are suitable for explosion-proof environments or rapid opening and closing requirements; hydraulic actuators are used for high-torque, large-diameter valves.
Sealing Class Requirements: Centerline butterfly valves are typically Class VI (minor leakage is permissible), while triple eccentric butterfly valves can reach Class V or zero leakage (metal hard seal).
Maintenance Points
Visual Inspection: Regularly inspect the valve's appearance, including the valve body, stem, and actuator. Clean dust, oil, rust, and other contaminants from the surfaces to maintain a clean appearance.
Connection Inspection: Carefully check the bolts and nuts connecting the valve to the pipeline for looseness, damage, or missing parts. Tighten or replace them promptly if necessary. Also, check the flange sealing surfaces for damage, deformation, or corrosion to ensure good sealing performance.
Air Supply System Maintenance (Pneumatic Type): Ensure the air supply is clean. Regularly drain water and impurities from the air filter. Check the oil level in the lubricator and replenish lubricating oil as needed. Check the air supply pressure at least once a day to ensure it is within the specified operating pressure range.
Actuator Maintenance: Regularly manually operate or remotely control the valve to observe whether the actuator's movement is flexible and smooth, and whether there is any jamming, shaking, or abnormal noise. Inspect the actuator seals, such as piston seals and O-rings. Replace any seals found to be aged, cracked, or worn. Regularly apply an appropriate amount of lubricant to moving parts of the actuator, such as the piston rod and shaft.
Internal valve inspection: Periodically disassemble the valve and inspect the sealing surfaces of the valve plate and seat for wear, corrosion, scratches, or deformation. Minor damage can be repaired by grinding; severe damage requires immediate replacement. Inspect the valve stem for bending, deformation, corrosion, or wear, ensuring a secure connection between the valve stem and valve plate. While inspecting, use compressed air or a clean cloth to clean impurities, dirt, and rust from inside the valve.
Pneumatic Wafer Type Centerline Butterfly Valve in stock
