Understanding The Difference Between Single and Double Flange Butterfly Valves

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The difference between double flange butterfly valves and single flange butterfly valves mainly lies in their structure, installation method, pressure capability, and typical applications. Choosing the right type affects system safety, sealing reliability, and maintenance efficiency.

1. Structural Design

A double flange butterfly valve has two full flanges, one on each side of the valve body.This structure offers excellent alignment and stability.

  • ①Bolts directly to both pipeline flanges

  • ②Valve becomes a fixed part of the pipeline

  • ③Provides strong mechanical support

A single flange butterfly valve has one flange, usually on one side, while the other side connects differently.This design saves space and reduces weight.

  • ①One flanged connection

  • ②The opposite side may be wafer-type or spigot-style

  • ③Lighter and more compact

2. Installation Method

Double Flange:Installed using bolts on both sides.Requires more installation space.Easy to align during mounting.The valve can handle higher tightening forces.

Single Flange:Installed with fewer bolts.Faster to install.Limited axial support.Alignment accuracy depends more on pipeline conditions.

d flange butterfly valve

3. Pressure and Strength CapabilityDouble Flange Butterfly Valve

  • ①Better suited for medium to high pressure systems

  • ②Strong resistance to pipe movement and vibration

  • ③Suitable for larger pipe diameters

Single Flange Butterfly Valve

  • ①Generally used in low to medium pressure systems

  • ②Less resistant to mechanical stress

  • ③Best for smaller or less critical pipelines

4. Sealing Performance

Double flange valves:More uniform gasket compression.Better long-term sealing reliability

Single flange valves:Depend more on installation accuracy.May experience uneven sealing under stress

5. Maintenance and ReplacementDouble Flange

  • ①Easy to remove as an independent pipeline section

  • ②Suitable for systems requiring frequent maintenance

Single Flange

  • ①Removal may affect pipe alignment

  • ②Better for systems with limited maintenance needs

s flange butterfly valve

6. Typical ApplicationsDouble Flange Butterfly Valves

  • ①Marine pipelines

  • ②Water treatment plants

  • ③Power stations

  • ④Large-diameter industrial systems

Single Flange Butterfly Valves

  • ①HVAC systems

  • ②Compact piping layouts

  • ③Light industrial applications

  • ④Cost-sensitive projects

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Company Name: Qingdao I- Flow Co., Ltd.
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Address:Unit 1517-1520, Building 4, Excellence Century Center, No. 31 Longcheng Road
City: Qingdao
Country: China
Website: https://www.iflowmarinevalves.com/