BUTTERFLY VALVE ASSEMBLY
🦋 Butterfly Valve – Full Details
🔧 What is a Butterfly Valve?
A butterfly valve is a quarter-turn rotational motion valve used to regulate or isolate the flow of a fluid (liquid or gas). It uses a disc as the closing mechanism which rotates to open or close the flow path.
⚙️ Basic Working Principle:
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The disc is mounted on a rotating shaft.
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When the valve is fully closed, the disc blocks the flow path.
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When the valve is fully open, the disc is rotated a quarter turn to allow flow.
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Intermediate positions allow for throttling.
🧩 Main Components:
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Body – Housed between two pipe flanges.
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Disc – The flow-controlling element.
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Seat – Seals between the disc and the body to prevent leakage.
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Stem/Shaft – Connects the actuator or handle to the disc.
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Actuator – Manual (lever), electric, pneumatic, or hydraulic operation.
📦 Types of Butterfly Valves:
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| Type | Description | Use Case |
|---|---|---|
| Concentric | Disc and stem centered in the seat | Low pressure, general purpose |
| Double Offset (High Performance) | Stem is offset from disc and body | Higher pressure and temperature |
| Triple Offset | Stem and disc are offset with a cone profile | Tight shut-off, high-performance industries |
🛠 Materials Used:
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Body: Cast Iron, Stainless Steel, PVC
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Disc: Stainless Steel, Aluminum Bronze, Nylon-coated
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Seat: EPDM, PTFE, Viton, Nitrile
🌍 Applications:
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Water supply and treatment
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Chemical and food processing
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Fire protection systems
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HVAC (Heating, Ventilation, and Air Conditioning)
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Oil & Gas
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Marine systems
✅ Advantages:
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Compact and lightweight
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Fast operation (90° turn)
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Cost-effective
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Low maintenance
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Suitable for large diameter pipes
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Throttling capabilities (some designs)
❌ Limitations:
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Not suitable for high-pressure drops
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Potential for pressure loss and turbulence
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Throttling can cause disc vibration at certain flow rates
