Proper Installation & Positioning of Butterfly Valves
Publish Time: 2025-03-20 Origin: Site
Butterfly valves are widely used in industrial piping systems due to their compact structure, easy installation, and excellent flow control capabilities. They are especially suitable for applications where space is limited or pipe spacing is tight. When fully open, the valve offers minimal resistance to fluid flow, resulting in a low pressure drop, making it highly efficient for flow regulation.
Preparing for Installation
Before starting the installation, proper preparation is essential to ensure optimal valve performance and avoid potential issues:
Check the valve: Verify that the butterfly valve matches the required specifications and inspect it for any damage or deformation.
Gather tools: Prepare necessary installation tools such as bolts, nuts, gaskets, and wrenches.
Clean the pipeline: Ensure the inside of the pipeline is free from debris, welding slag, or any foreign objects that could affect sealing or damage the valve seat.
Installation Steps
Proper installation is crucial for ensuring a tight seal, preventing leaks, and maintaining operational safety. Understanding the process will help achieve a secure and efficient setup.
Example: Installation of a Wafer-Type Butterfly Valve
Determine Installation Orientation
Vertical Installation (Recommended): The valve stem should be perpendicular to the ground for easier operation with a handwheel or actuator.
Horizontal Installation: If space is limited, the valve stem can be positioned horizontally. Ensure the flow direction follows the arrow marked on the valve body. (Some butterfly valves do not have strict direction requirements, but following the markings is advised.)
Position the Valve
Place the butterfly valve between the two pipeline flanges, keeping the disc slightly open (about 5°–10°) to prevent the seal from being compressed.
Install Gaskets
Position a sealing gasket on the flange face on each side of the valve, ensuring they are properly aligned and cover the entire sealing surface.
Insert and Secure Bolts
Use double-end studs or long bolts to pass through the pipeline flange and valve flange holes. Hand-tighten the nuts to ensure the valve is centered with the flanges.
Bolt Tightening Sequence
Tighten the bolts in a diagonal (cross) pattern to distribute force evenly and prevent leaks. Follow the recommended torque values according to valve or flange standards (e.g., ISO, ANSI) to avoid over-tightening, which could damage the gasket.When tightening flange bolts, follow the recommended sequence to ensure the flange surfaces are pulled together evenly.
Initial Hand-Tightening: First, tighten the bolts by hand to secure the alignment.
Gradual Tightening with a Wrench:
Tighten each nut one full turn initially.
Then, continue tightening in increments of ½ turn per cycle.
Final Torque Application: Once fully assembled, tighten the flange bolts to the specified torque settings suitable for the operating pressure and temperature, following the same diagonal sequence.
Final Valve Testing
Operational Test: Fully open and close the valve to check if the disc moves smoothly without obstruction.
Actuator Inspection (for Electric or Pneumatic Valves): Ensure the actuator's travel settings are correctly adjusted so the disc fully opens and closes without misalignment or interference.
Leak Test: Introduce the working medium at the appropriate pressure and check for any leakage around the valve.
Butterfly Valve Pipeline Installation Position
The installation direction and position of a butterfly valve significantly impact its lifespan and sealing performance. Below are key installation guidelines for different scenarios.
1. Matching the Installation of a Butterfly Valve with a Centrifugal Pump
Align the Pump Shaft with the Valve Stem:
If the pump shaft is vertical, the butterfly valve stem should also be vertical.
If the pump shaft is horizontal, the butterfly valve stem should also be horizontal (as shown in the "CORRECT" example).
Consequences of Incorrect Installation:
If the valve stem direction does not match the pump shaft, the fluid flow will impact the valve disc unevenly.
This misalignment can lead to vibration, noise, and accelerated wear of the sealing components (as shown in the "INCORRECT" example).
2. Installing Butterfly Valves Downstream of Axial Pumps and Elbows/Reducers
Installation After an Axial Pump
If the pump shaft is horizontal, the butterfly valve stem should be vertical.
If the pump shaft is vertical, the butterfly valve stem should be horizontal (as shown in the "CORRECT" example).
Installation Downstream of an Elbow or Reducer
The valve stem should be perpendicular to the flow direction (as shown in Figure 1).
Avoid horizontal installation, as it can cause flow deflection and vibration, leading to uneven wear on the valve disc and sealing surfaces.
3. Installation Guidelines for Tees, Reducers, and Multiple Valves
Installing a Butterfly Valve Downstream of a Tee or Reducer
The valve stem should be perpendicular to the main flow direction (as shown in Figures 2 and 3).
This ensures a symmetrical flow field, reducing turbulence and impact forces on the valve disc.
Installing Multiple Butterfly Valves
Incorrect Installation: If all valve stems are aligned in the same direction, fluid disturbances increase, leading to higher noise, vibration, and potential erosion (as shown in the "INCORRECT" example).
Correct Installation: The control valve stem should be positioned at a right angle to the other valve stems (as shown in the "CORRECT" example).
This helps counteract fluid drift and minimizes negative effects such as uneven pressure distribution and excessive wear.
The correct installation of butterfly valves is essential for maintaining sealing integrity, operational safety, and extended service life in piping systems. To achieve optimal performance, it is crucial to:
Follow proper valve stem orientation to minimize flow disturbances.
Use appropriate tightening methods to prevent leaks and structural damage.
Conduct thorough testing to ensure smooth operation and reliable sealing.
Additionally, choosing the right installation position can prevent issues such as fluid impact, seal damage, or disc misalignment, ultimately enhancing the overall efficiency and durability of the valve.
Choose TFW Valve for a More Reliable Piping System
As a leading manufacturer in the butterfly valve industry, TFW Valve is committed to delivering high-quality valve solutions that ensure stability and safety in your piping systems. We offer a wide range of butterfly valve sizes from 2 inches to 24 inches, designed to meet diverse system requirements.
If you're looking for high-performance, dependable butterfly valves,choose TFW Valve—we provide premium products and expert technical support to help optimize your pipeline operations!