Butterfly Valve Installation & Maintenance

Butterfly valves require careful installation and consistent maintenance for their optimal functionality. This article provides a detailed guide on butterfly valve installation, emphasizing the key factors to consider to prevent future operational issues. It further highlights the significance of regular maintenance in enhancing the valve's efficiency and durability. Read our butterfly valve overview article for more details on the working and types of butterfly valves.

Table of contents

• Pre-installation guidelines
• How to install a butterfly valve
• Troubleshooting common installation problems
• How to repair a butterfly valve
• Butterfly valve maintenance procedure
• FAQs

Pre-installation guidelines

Before installing a butterfly valve, careful planning and preparation are crucial to ensure the proper installation and operation of the valve.

• Ensure the operational conditions, like temperature and pressure, fall within the recommended range of the installed butterfly valve.
• Verify that the butterfly valve's construction material is chemically compatible with the medium used.
• Examine the valve's flange ends and the pipeline's mating flanges to ensure they are clean and defect-free. Also, ensure the pipeline is properly aligned.
• Verify that there is enough clearance for the valve installation by measuring the distance between the pipe flanges.
• Keep necessary lifting equipment readily available to position larger valves.
• Confirm that the sizes of the existing pipes align with the inlet and outlet sizes of the valve being installed and that there's no obstruction. Additional support may be required for larger valves where the valve's weight can cause strain to the pipeline.
• Install butterfly valves at least six pipe diameters away from upstream components and four pipe diameters away from downstream components for optimal performance. This helps reduce turbulence and flow disturbances, ensuring efficient valve performance by stabilizing flow.

How to install a butterfly valve

Installation direction

The butterfly valve installation direction refers to the orientation in which the valve is installed in relation to the flow of the medium.

• Horizontal orientation: In most cases, butterfly valves are installed horizontally, meaning the valve's stem is positioned horizontally, and the disc opens and closes in a vertical plane. This orientation allows for easy operation and maintenance as gravity helps to close the valve, and the handle or actuator is easily accessible.

• Vertical orientation: Butterfly valves can also be installed vertically, with the stem positioned vertically and the disc opening and closing in a horizontal plane. This orientation may be used when space is limited or the pipeline runs vertically. In this orientation, it's important to consider the flow direction. If the flow is from bottom to top, the valve may close more easily due to the force of gravity. However, if the flow is from top to bottom, the force of gravity may make it harder to close the valve.

Regardless of the orientation, it's important to consider the flow direction, which is usually indicated by an arrow on the valve's body. The valve should always be installed so that the flow of the medium matches this direction. This ensures optimal performance and minimizes wear and tear on the valve. However, if there's a choice, install the valve with the stem horizontally. This distributes the weight of the stem and disc evenly, minimizing seat wear. Moreover, if the media is abrasive, this configuration creates a self-cleaning effect, thereby extending the valve's lifespan.

Installation procedure

Before starting the installation process, it is important to review the manufacturer's instructions carefully. The common steps in installation are:

1. Positioning: The valve should be properly aligned with the pipe where it will be installed. Ensure that the butterfly disc is open to prevent any damage during installation.

1. Concentric butterfly valves: Also known as resilient-seated butterfly valves, these valves have a rubber seat and a disc centered in the middle. The installation process involves aligning the valve between two pipe flanges and securing it using bolts. After securing the valve, the disc can be rotated to ensure it doesn't interfere with the valve seat or pipe flanges.
2. Double offset butterfly valves: Installation of double offset butterfly valves involves careful alignment of the valve in the pipeline to ensure the disc can rotate freely without hitting the pipe flanges. The offset design may require more careful positioning and alignment than a concentric butterfly valve.
3. Triple offset butterfly valves: Installing a triple offset butterfly valve requires precision to ensure the offsets align correctly with the pipeline. This may require more complex mounting procedures and should be done by trained professionals.

2. Securing the butterfly valve: Once the valve is positioned, it must be secured. This is typically done by bolting the valve between two pipe flanges. The bolts should be tightened evenly to avoid unnecessary stress or distortion of the valve.

1. Lugged butterfly valves: Lugged butterfly valves have threaded sockets on both sides of the valve body, allowing them to be installed in a system using two bolt sets without the need for nuts. The valve is positioned between two flanges, with a pair of bolts securing each flange. This design allows either side of the piping system to be disconnected independently without affecting the other side.
2. Wafer butterfly valves: Wafer butterfly valves are installed by sliding the valve between the flanges on the pipe, then the flanges are tightened onto the valve to hold it in place. This makes them easy to install and disassemble, but they cannot be used when the flow needs to be disrupted.

3. Connecting the actuator: Attach the handle (for manual valves) or gearbox to the valve. This is usually connected to the top of the valve and must be properly aligned to ensure correct operation.
4. Testing the butterfly valve: After installing the valve and connecting the actuator, it's essential to test its operation.

1. Visual inspection: Check the valve for any visible damages. Ensure it is installed correctly.
2. Operational test: Operate the valve to verify it opens and closes smoothly without any hitches.
3. Leakage test: With the valve closed, introduce a fluid pressure on one side and check for any leaks.
4. Functional test: Monitor and verify that the valve works as expected under normal operating conditions.
5. Performance test: Check for any performance issues such as unusual noises, vibrations, or temperature variations.

5. Final adjustments: The last step is to make any necessary adjustments. This might include tightening the bolts further, adjusting the positioning of the valve, or fine-tuning the actuator. Once all adjustments are made, the installation process is complete.

Troubleshooting common installation problems

Troubleshooting common installation problems in butterfly valves ensures their proper functioning within various industrial processes.

• Misalignment: Ensure that the valve and pipe flanges are correctly aligned before securing the valve.
• Difficulties in securing the valve: If there are troubles in securing the valve, ensure that the bolts are the correct size and that the bolt holes on the valve and flanges align correctly. If the valve still can't be secured, it may be due to a problem with the valve or flanges.
• Issues with testing the valve's operation: If the valve doesn't operate smoothly during testing, it may be due to the disc catching within the valve or pipe, or the actuator being improperly connected or adjusted. Check each of these areas and correct them as necessary.

How to repair a butterfly valve

The first step in any repair process is to identify the problem. For butterfly valves, common issues are:

• Leakage, which may be due to worn out seals or gaskets
• Difficulty in turning the handle
• The valve not closing or opening fully

Once the problem has been identified, determine if a repair or replacement is needed. Some issues, such as a stiff handle or minor leaks, can be repaired. This might involve lubricating the valve stem, adjusting the actuator, or replacing worn-out seals. Always remember to shut off the flow and relieve any pressure in the line before starting any repair work.

Replacing butterfly valve components

• Handle: Unscrew the old handle from the valve stem. Once the old handle is removed, you can attach the new handle and secure it in place. Make sure the new handle is compatible with your specific valve model.
• Seal or gasket: Shut off the flow, relieve the system pressure, and remove the valve from the pipeline. Then, remove the disc and replace the old seal and gasket with new ones. Ensure to clean the seating area. Reassemble and reinstall the valve.

If the butterfly valve is seriously damaged or worn out, replacing the entire valve might be more cost-effective. This involves removing the old valve from the pipeline and installing a new one in its place. Ensure the new valve matches the specifications of the old one, including size, type, and material.

Butterfly valve maintenance procedure

Regular maintenance is key to ensure the butterfly valve continues to function optimally. This includes periodic checks, testing of the valve's operation, and inspection for signs of wear or damage. Be alert for signs that the valve may not be working correctly. This can include leaks, unusual noises when the valve operates, or failing to open or close fully. The valve may need adjustment or repair if any of these signs are observed.

• Verify that the valve functions correctly in both the fully closed and fully open positions. Adjust if necessary.
• Visually inspect the valve and its surroundings to check for any signs of leakage. Check the gearbox regularly for any signs of wear, corrosion, or damage. Lubricate the gearbox regularly to reduce friction and wear.
• Inspect bolts, piping, wiring, and any other related equipment visually for issues that could interfere with operation, such as loosening or corrosion.

FAQs

What should I consider when purchasing butterfly valve replacement parts?

Ensure the parts are compatible with your valve model, made of suitable material for your application, and from a reputable manufacturer.

What is the butterfly valve testing procedure?

Butterfly valve testing involves visual inspection, operational test for smooth opening/closing, leakage test for leaks, functional test under normal conditions, and performance test for noise or vibration.

How can I replace a butterfly valve's gasket, seat, and handle?

Shut off the flow and relieve pressure. Remove the valve from the pipeline. Replace the old gasket, seat, and handle with compatible new ones, and reinstall the valve.

What is the correct installation orientation for a butterfly valve?

Butterfly valves can be installed horizontally or vertically, but the preferred orientation is with the stem on top for easy operation and maintenance. Also, check an arrow on the valve's body that indicates its flow direction.