What is the difference between a flanged and wafer butterfly valve?
Structure and Installation Methods
1. Wafer Type Connection
Structural Features: The valve itself has no flange; both ends of the valve body are smooth sealing surfaces, secured solely by the flanges on both sides of the pipe (requires specialized gaskets, such as nitrile rubber or PTFE gaskets).
Installation Procedure:
Place the valve between two flanged pipe sections, aligning the bolt holes;
Insert the gaskets (one on each side of the valve body; some integrated valve designs require only one gasket);
Put in the bolts and tighten them evenly diagonally. The seal is achieved through the clamping force of the pipe flanges.
Key Components: No built-in flange is required; only bolts, nuts, and gaskets matching the pipe flange specifications are needed.
2. Flanged Type Connection
Structural Features: The valve has integrally cast or welded flanges at both ends. The flanges have pre-drilled bolt holes for direct face-to-face connection with the pipe flanges.
Installation Procedure:
Place one gasket between the valve flange and the pipe flange;
Align the bolt holes, insert the bolts, and tighten them diagonally. The seal is achieved through the bolt preload.
Key Components: Bolts, nuts, and a single gasket (only between the valve and pipe flanges) matching the flange specifications.
Recommended Application Scenarios
1. Application Scenarios for Wafer Butterfly Valves
Space-constrained scenarios: such as pump rooms with dense piping, internal equipment piping;
Low-to-medium pressure, normal temperature media: such as tap water, sewage treatment, HVAC systems (medium pressure ≤ 1.6 MPa, temperature ≤ 120℃);
Cost-sensitive scenarios with low maintenance frequency: such as municipal water supply and drainage projects, general industrial circulating water systems.
2. Application Scenarios for Flanged Butterfly Valves
High-pressure, high-temperature media: such as petrochemical and natural gas transportation (medium pressure ≥ 2.5 MPa, temperature ≤ 400℃);
Scenarios requiring high sealing: such as flammable and explosive media (e.g., liquefied petroleum gas, methanol), toxic and harmful media (e.g., acid and alkali solutions), where leakage risk must be avoided;
Scenarios requiring frequent maintenance: such as pipelines in chemical production processes where valves need regular maintenance;
Large-diameter valves (DN ≥ 300): Large-diameter wafer valves are difficult to align on both sides during installation; flanged valves are easier to install and provide more stable sealing.
Selection Considerations
Media Parameter Priority: If the medium pressure > 1.6 MPa or temperature > 120℃, flange type is preferred; for low pressure and normal temperature, wafer type can be considered.
Installation Space Check: If the axial space of the pipeline is insufficient (e.g., small distance between equipment inlet and outlet), wafer type is the only option.
Maintenance Frequency Assessment: For pipelines requiring frequent maintenance (e.g., feed valves for chemical reactors), flange type should be selected to reduce downtime for maintenance.
Pipeline Compatibility: If the existing pipeline already has flanges, the flange specifications (e.g., PN1.6/DN100) must be confirmed to avoid mismatched connection dimensions (for wafer type, the flange spacing between the pipeline and the valve body length must be confirmed to match).
Flange and wafer butterfly valve in stock
