Introduction to the Selection and Application of Butterfly Valves for Water Applications

Butterfly valves are commonly used in water applications due to their reliable sealing performance, low flow resistance, and ease of operation. This article provides an overview of the selection criteria and application conditions for butterfly valves in water applications.

Selection Criteria

1. Fluid Characteristics: The fluid characteristics including corrosiveness, viscosity, temperature, and suspended solids or debris determine the materials and sizes of the butterfly valves. For example, corrosive fluids require a valve made of stainless steel or have a rubber lining.

2. Flow Rate: The flow rate and the valve size are interrelated, which is dependent on the valve's flow coefficient. The higher the flow coefficient, the smaller the valve's size required.

3. Pressure: The valve's pressure rating should be about 1.5 to 2 times greater than the system pressure. This ensures the butterfly valve can withstand the required operation pressure conditions.

4. Installation Space: Butterfly valves have a compact design and require less installation space. The installation space should be considered when choosing the valve's size and connection type.

Application Conditions

1. Flow Control: Butterfly valves are commonly used to regulate the flow rate in water systems. The valve's actuator type and control signal are crucial parameters that must be chosen based on the control requirements.

2. Emergency Shut-off: Butterfly valves can quickly close in an emergency to prevent water hammer or system damage. The valve should have a fail-safe design for reliable operation during emergency situations.

3. Water Treatment: Butterfly valves are commonly used in water treatment systems for adjusting pH levels or controlling the dosage of disinfectants. The valve's materials and sealing design must be selected carefully to avoid any potential contamination by the water treatment chemicals.

4. Irrigation: Butterfly valves are used in irrigation systems for controlling the flow of water to the field. The valve's material and construction are crucial parameters that must be selected based on the properties of the irrigation water.

Conclusion

Butterfly valves are widely used for water applications due to their excellent sealing performance, low flow resistance, and easy operation. Selecting the appropriate butterfly valve depends upon the fluid characteristics, flow rate, pressure, and installation space. Their application conditions include flow control, emergency shut-off, water treatment, and irrigation systems. By selecting the right butterfly valve, water systems can operate efficiently and effectively without any downtime or system damage.