How to Measure Butterfly Valves

Butterfly valves are widely used in industrial and domestic applications to regulate fluid flow. Measuring a butterfly valve correctly is crucial for ensuring proper installation, compatibility with piping systems, and optimal performance. Here’s a step-by-step guide to measuring butterfly valves:  

1. Understand the Components to Measure  

Before measuring, familiarize yourself with the parts of a butterfly valve that require dimensioning:  

- Valve Body: The main housing that contains the disc and seat.  

- Disc: The circular plate that rotates to control fluid flow.  

- Seat: The sealing surface between the disc and the valve body.  

- Stem: The shaft connected to the disc, which transfers motion from the actuator.  

- Flanges: The connection points between the valve and the pipeline.  

2. Tools You’ll Need  

- Measuring tape or caliper  

- Reference specifications or datasheets  

- Pipe size gauge (optional)  

3. Steps to Measure a Butterfly Valve  

a) Determine Valve Size  

- Nominal Diameter (DN): Measure the inside diameter of the pipe the valve will be installed in. The valve’s size should match the nominal diameter of the pipe.  

- Valve Bore: Measure the internal diameter of the valve when fully open to ensure it matches the pipe bore.  

b) Measure Face-to-Face Distance  

- Face-to-Face Distance: Measure the distance between the two flanges (or ends) of the valve body. This is critical for ensuring the valve fits within the pipeline system.  

c) Measure Flange Dimensions  

- Measure the outer diameter (OD) of the flanges.  

- Check the bolt circle diameter (BCD): The diameter of the circle formed by the center points of the bolt holes.  

- Count and measure the bolt holes: Verify the number of holes and their diameter.  

d) Measure the Valve Disc  

- Measure the diameter of the valve disc. Ensure it does not interfere with the internal diameter of the pipe or fittings when fully opened.  

e) Check Stem Length and Diameter  

- Measure the length of the valve stem to confirm it fits your actuator or handle requirements.  

- Measure the stem diameter to ensure compatibility with actuators or manual operators.  

f) Check for Clearance  

- Handle or Actuator Clearance: If the valve uses a lever or actuator, measure the clearance required around the stem to operate it freely.  

4. Important Considerations  

a) Standards and Specifications  

Butterfly valves are manufactured according to specific standards such as ANSI, DIN, or JIS. Ensure the measurements comply with the standard relevant to your region or application.  

b) Pressure Rating  

Verify the valve's pressure class (e.g., PN10, PN16) to ensure it meets the system's operating pressure requirements.  

c) Material Compatibility  

While not a direct measurement, ensuring the valve material (e.g., stainless steel, ductile iron) is compatible with the fluid being handled is critical.  

d) Seat and Seal Inspection  

Inspect the valve seat dimensions and sealing surfaces for wear or damage. Ensure the seat diameter matches the disc dimensions for a proper seal.  

5. Using Manufacturer Datasheets  

Many butterfly valves come with detailed technical datasheets. Cross-check your measurements with the datasheet to confirm the valve meets your system requirements.  

Conclusion  

Measuring a butterfly valve accurately ensures a proper fit, optimal performance, and long-term reliability. By following this guide and considering all critical dimensions, you can confidently select or replace a butterfly valve that integrates seamlessly into your system.

Tianjin Fuyaolai Technology Co., Ltd. is factory located in Tianjin China. Factory specialized in producing different type of valves. Butterfly valve is one of major products. We have all types of butterfly valves such as wafer butterfly valve, Soft/metal seal double eccentric flange butterfly valve, triple eccentric butterfly valve and so on. Technician would be give full advice for clients request in order to confirm they get proper product. Welcome inquiries from all over the world. Visit our website at www.fuyaolaivalve.com to learn more about our products. For inquiries, you can reach us at sales@fylvalve.com.