The main differences between a butterfly valve and a gate valve are:
1. **Valve Design**:
- Butterfly valve: Has a circular disc that rotates on a shaft to open and close the valve. The disc pivots across the pipe diameter to control the flow.
- Gate valve: Has a flat, circular or wedge-shaped gate that slides in and out of the valve body to open and close the flow path.
2. **Flow Characteristics**:
- Butterfly valve: Provides a more linear flow characteristic, Extension Stem Manual Butterfly Valve meaning the flow rate changes more proportionally with the valve position.
- Gate valve: Provides a more on/off flow characteristic, where the flow is either fully open or fully closed, with less fine control between.
3. **Pressure Drop**:
- Butterfly valve: Generally has a lower pressure drop when fully open compared to a gate valve of the same size.
- Gate valve: Can have a higher pressure drop when fully open due to the flow having to make sharper turns around the gate.
4. **Ease of Operation**:
- Butterfly valve: Requires fewer turns of the valve stem to fully open/close, making them quicker and easier to operate.
- Gate valve: Typically require more turns of the valve stem to fully open/close.
5. **Cost and Size**:
- Butterfly valve: Generally less expensive and more compact than a gate valve of the same pipe size.
- Gate valve: Tend to be larger and more costly, especially for larger pipe sizes.
In summary, butterfly valves are more suitable for applications requiring frequent throttling and a more linear flow control, while gate valves are better for on/off flow control where the pressure drop is less critical.
