As an important fluid control component, butterfly valves are widely used in pipeline systems. However, the leakage problem of butterfly valves is often a headache, especially when it is operated incorrectly or improperly maintained, the risk of leakage will increase significantly. This article will take an in-depth look at what incorrect practices can cause butterfly valve leaks, how to avoid them, and how to fix the problem if a leak occurs.
Common types of incorrect operations
1.1 Improper installation
The installation quality of butterfly valve directly affects its service life and sealing performance. If there are deviations or errors during installation, the valve may not close or open properly, causing leaks.
Common installation errors include:
Incorrect installation position: The butterfly valve needs to be installed to ensure that it is aligned with the center of the pipe. If misaligned, the valve plate will be subject to uneven pressure when opening or closing, causing wear or damage to the sealing surface, which can lead to leakage.
The flange connection is not tight: When installing the butterfly valve, the flange connection is too tight or too loose, which will cause problems. Too tight will cause the sealing surface to deform, while too loose will cause the medium to leak from the flange connection.
1.2 Improper use
During the use of butterfly valves, incorrect operating habits or misunderstandings can cause damage to the valve and cause leakage problems.
Common incorrect operations include:
Overload Operation: Butterfly valves are usually designed for use within a specific pressure and temperature range. If operated beyond design parameters, the valve body and seals may be damaged, resulting in leakage.
Frequent switching operations: Frequent switching of butterfly valves will accelerate the wear of the sealing surface, especially in high-pressure and high-temperature environments, the wear rate will be faster.
Wrong operating direction: The opening and closing directions of some butterfly valves are fixed. If they are opened or closed in the opposite direction during operation, the seal may be damaged and leakage may occur.
1.3 Improper maintenance
Regular maintenance of butterfly valves is essential to ensure their long-term stable operation. However, wrong maintenance methods are often counterproductive. Common maintenance mistakes include:
Lack of regular inspection: If the butterfly valve is not inspected for a long time, its sealing surface may suffer from wear, corrosion and other problems, eventually leading to leakage.
Incomplete cleaning: In some pipelines containing particulate matter or corrosive media, the sealing surface of the butterfly valve is easily affected by media residues, resulting in a decrease in sealing performance. If cleaning is not thorough, residue may build up and damage the sealing surface.
Failure to replace damaged parts in time: When seals or other key components are found to be aged or damaged, leakage problems will be unavoidable if they are not replaced in time.
How to avoid incorrect operations?
2.1 Correct installation method
To avoid leakage problems caused by improper installation, be sure to take the following measures:
Ensure center alignment: When installing, make sure the butterfly valve is aligned with the center of the pipe and avoid collision between the valve plate and the pipe wall. Professional alignment tools can be used to ensure installation accuracy.
Connect flanges correctly: When tightening flange bolts, a diagonal step-by-step tightening method should be used to ensure uniform force application and avoid deformation of the sealing surface. In addition, the flange gasket should be made of media-compatible materials to ensure a good sealing effect.
2.2 Standardize operating procedures
By standardizing the operating procedures, the risk of butterfly valve leakage can be significantly reduced:
Follow design parameters: When operating a butterfly valve, the designed pressure and temperature range must be strictly followed to avoid overload operation. Especially in high temperature and high pressure environments, operators should be more cautious.
Avoid frequent switching: Unless necessary, try to avoid frequent operation of the butterfly valve, especially in harsh environments. This extends the life of the seal and reduces the risk of leaks.
Correct operating direction: Read the operating instructions of the butterfly valve in detail before operation to ensure that the valve is opened or closed in the correct direction.
2.3 Regular maintenance and upkeep
Scientific maintenance is the key to ensuring long-term and stable operation of butterfly valves. The following measures are recommended:
Develop a regular inspection plan: Develop a detailed inspection plan based on the nature of the pipeline medium and the working environment of the butterfly valve. For pipelines containing corrosive media or particulate matter, inspection frequency should be increased.
Cleaning and lubrication: Clean the sealing surface of the butterfly valve regularly to ensure that there is no residue. Additionally, proper lubrication reduces friction and extends seal life.
Replace components in a timely manner: When seals, valve stems or other key components are found to be aging or worn, they must be replaced immediately to prevent leakage.
How to solve the problem of butterfly valve leakage?
Even with all the precautions taken, sometimes a butterfly valve can still leak. In this case, the following steps should be taken to resolve:
3.1 Preliminary inspection
When a butterfly valve is found to be leaking, a preliminary inspection is first needed to determine the specific location and cause of the leak:
Check the flange connection: If the leak occurs at the flange connection, it may be due to a loose connection or an aged gasket.
Check the sealing surface: If leakage occurs between the valve plate and the sealing surface, it may be caused by wear of the sealing surface or deformation of the valve plate.
Check the valve stem and packing: If the leakage occurs at the valve stem, it may be caused by a loose packing gland or aging packing.
3.2 Taking temporary measures
Where immediate repair is not possible, there are some temporary measures that can be taken to reduce the impact of the leak:
Increase the tightening force: For flange leakage, you can try to increase the tightening force of the bolts appropriately to ensure that the flange connection is tight.
Adjust the operating angle: For leakage caused by slight wear of the sealing surface, you can try to adjust the opening angle of the butterfly valve to find the best sealing position.
3.3 Repair and replacement
Once the initial inspection determines the cause of the leak, repair work should begin as soon as possible:
Replace the gasket or packing: If the problem lies with the flange gasket or stem packing, it is recommended to replace the corresponding parts immediately and ensure that the replacement part is compatible with the medium.
Repair or replace the sealing surface: If the sealing surface is lightly worn, grinding or spraying repair can be used to restore the sealing performance. But if the wear is severe, it’s best to replace the entire seal assembly.
Inspect butterfly valve: For leaks caused by damage to the valve body or valve plate, the butterfly valve may need to be disassembled and fully inspected or replaced.
3.4 Adjust operation and maintenance strategies
After the repair is completed, the existing operation and maintenance strategies should also be evaluated and adjusted to avoid similar problems from happening again:
Strengthen operational training: Ensure that operators fully understand the correct operation methods of butterfly valves to avoid leaks caused by human errors.
Optimize the maintenance cycle: Adjust the frequency of maintenance inspections based on the actual operating conditions of the butterfly valve. Especially in situations with harsh operating conditions, the inspection cycle should be shortened.
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