How to Repair and Maintain the Butterfly Valve

Flanged butterfly valve

As one of the important industrial valves for fluid treatment in pipelines, butterfly valves will suffer varying degrees of wear due to frequent use in long-term and harsh environments. Therefore, regular maintenance and repair are also necessary. Just replace necessary parts to avoid equipment shutdown or safety hazards caused by valve failure, which can extend the use of the valve and save costs.
What is the maintenance on a butterfly valve? Butterfly valve maintenance repairs may vary depending on the type of damage or failure. It can be divided into maintenance, general repair and heavy repair.

  • Maintenance refers to daily maintenance, and there is no need to disassemble the butterfly valve or replace parts. For example, when the butterfly valve is not in use, the accumulated water should be drained, regular lubrication should be performed, and the butterfly valve should be checked regularly for leaks.
  • General maintenance refers to valve stem straightening, connecting bolt tightening, etc.
  • Severe maintenance requires the replacement of valve plates, valve seats and other major items.

What are the main parts of a butterfly valve?

all part for the wafer butterfly valve










The main Parts of butterfly valves including:







so, How to fix butterfly valve?

1. The first step in maintenance is to determine the fault problem.

How do you troubleshoot a butterfly valve? Thoroughly inspect the valve and surrounding components. Only by identifying the exact cause of the problem can you treat it appropriately. For example, there may be a leak caused by a loose connection. There is no need to remove the valve and replace the valve seat, just like there is no need to have surgery if you have a cold.

Leakage - Loose bolts, valve seats and seals may age, causing leakage and affecting the valve's sealing ability.
Wear - Within a valve, the disc, stem and seals are subject to wear and tear due to standard operation, resulting in reduced performance and leakage
Corrosion - Over time, continued exposure to corrosive environments can cause material damage
Stuck valve stem - Due to the entry of foreign matter, the valve stem may become stuck, causing the valve to not function properly.

2. If the valve really needs to be disassembled, then we move on to the second step.

Before disassembly, please close the upper-level valve to prevent fluid flow and depressurize the system to ensure safety. Remove all connections to the valve and disconnect the electric or pneumatic actuator (if present). Use appropriate tools to loosen and remove bolts or fasteners holding valves and pipes in place.
Warm reminder: Pay attention to the arrangement and orientation of components for reassembly.

3. Check for damage:

After removing the valve, inspect the appearance of each component for signs of damage, wear, or corrosion. Check the disc, stem, seat, seals and any other related parts for cracks, corrosion or deformation.
The process of disassembling the butterfly valve is shown in the video below.

4. Repair and replace faulty components

If there are impurities stuck between the valve plate and the valve seat, first remove the impurities and observe whether the valve seat is deformed due to this.
If the valve stem is deformed, it can be removed and straightened.
If any part is found to be damaged or worn beyond repair, it should be replaced with a suitable replacement. Make sure the replacement part is of the same specification as the original part. Common parts that may need to be replaced include seals, stems, and O-rings.

5. Reassemble the valve

Reassemble the butterfly valve in the reverse order of disassembly. Clean and lubricate parts as needed to ensure smooth operation and proper sealing. Tighten bolts or fasteners, being careful not to overtighten to avoid damaging valve components or surfaces.

6. Test

After the valve has been reassembled, functionality must be tested before being put back into service. First, conduct a pressure test alone to observe the operation of the valve and check for leaks or abnormalities. Verify valve opening and closing.

7. Installation

Proper reinstallation procedures are critical to achieving optimal valve function, extending valve life, and ensuring safe and efficient operating conditions.
Repairing a butterfly valve involves a systematic approach to identifying, disassembling, inspecting, replacing, reassembling and testing components to restore their functionality. By following correct procedures and taking precautions, you can ensure reliable operation of your butterfly valve in a variety of industrial applications. If you are unsure about any aspect of the repair procedure, consult a qualified professional or refer to the manufacturer's guidelines for specific instructions.