Check valves are widely used in industrial piping systems to prevent backflow and protect pumps, compressors, and pipelines. However, during long-term operation, problems such as corrosion, wear, debris blockage, and improper installation can lead to valve failure.
Understanding common check valve problems and their solutions can help reduce downtime, improve pipeline safety, and extend valve service life.
This article explains the six most common check valve failure symptoms, their causes, and practical troubleshooting methods for industrial maintenance teams.
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1. Check Valve Cannot Close Properly and Backflow Occurs
One of the most common check valve failures is severe backflow caused by the valve not sealing completely.
Possible Causes
1) Valve disc stuck in the open position
2) Damaged sealing surface
3) Internal debris blockage
4) Corrosion inside the valve body
Troubleshooting Methods
1) Disassemble the valve and remove welding slag, rust, or foreign particles
2) Inspect the valve disc and seat sealing surfaces for wear or corrosion
3) Repair sealing surfaces by grinding or replace damaged valve components
Ignoring backflow problems may result in:
1) Pump reverse rotation
2) Equipment damage
3) Pipeline pressure instability
4) Water hammer
2. Check Valve Cannot Fully Open and Flow Rate Is Low
Insufficient flow is often related to incorrect installation or improper valve selection.
Possible Causes
1) Incorrect installation direction
2) Spring tension too strong
3) Insufficient pressure differential
Troubleshooting Methods
1) Verify that the flow direction matches the arrow on the valve body
2) Replace with a lower cracking pressure spring
3) Check whether the pipeline pressure difference meets opening requirements
Proper valve sizing is critical for maintaining stable system flow and preventing excessive pressure loss.
3. Repeated Clicking or Water Hammer Noise
Frequent “clicking” sounds usually indicate water hammer caused by rapid valve closing.
Possible Causes
1) Valve disc slamming against the seat
2) Sudden flow velocity changes
3) Oversized valve selection
Troubleshooting Methods
1) Upgrade to a silent check valve or non-slam check valve
2) Install a water hammer arrestor or surge tank
3) Verify whether the valve size is too large for the application
Water hammer can seriously damage:
1) Pumps
2) Pipelines
3) Flanges
4) Valve seats
4. External Leakage from Valve Body
External leakage is usually related to sealing component failure or casting defects.
Possible Causes
1) Aging gasket
2) Loose bolts
3) Valve body casting defects or cracks
Troubleshooting Methods
1) Tighten flange bolts evenly
2) Replace damaged sealing gaskets
3) Replace the valve immediately if cracks or casting holes are found
Pressure repair welding on damaged valve bodies is not recommended during operation.
5. Severe Disc Wear or Disc Breakage
Excessive wear significantly reduces check valve reliability and service life.
Possible Causes
1) Particle-containing media
2) Frequent rapid opening and closing
3) Incorrect material selection
Troubleshooting Methods
1) Choose wear-resistant or rubber-lined check valves
2) Install strainers or filters upstream
3) Upgrade to lift check valves or silent check valves to reduce impact wear
For abrasive media applications, material selection is especially important.
6. Valve Sticking in High or Low Temperature Environments
Extreme temperatures can affect internal clearances and valve movement.
Possible Causes
1) Thermal expansion or contraction
2) Freezing in low-temperature environments
3) High-temperature deformation
Troubleshooting Methods
1) Use high-temperature or cryogenic check valves
2) Install heat tracing or insulation systems in cold environments
3) Adjust installation clearances according to operating temperature
Special operating conditions require specially designed industrial valves.
Practical Check Valve Inspection and Maintenance Guide
Routine inspection is one of the best ways to prevent unexpected valve failures.
Daily Inspection Checklist
Listen for Abnormal Sounds
Check for:
1) Knocking
2) Friction noise
3) Disc impact sounds
These may indicate sticking or unstable operation.
Monitor Pressure Readings
Abnormal pressure fluctuations may indicate:
1) Incomplete opening
2) Reverse flow
3) Internal blockage
Check Valve Surface Temperature
Local overheating may suggest:
1) Internal blockage
2) Restricted flow
3) Disc sticking
Inspect for Leakage
Check:
1) Valve body
2) Flange connections
3) Gaskets
4) Bolts
Basic Check Valve Repair Procedure
When maintenance is required, follow these basic steps:
1) Stop the pump and fully release pipeline pressure
2) Isolate the pipeline before disassembly
3) Remove the valve cover and inspect internal components
4) Clean welding slag, rust, and debris
5) Repair or replace damaged sealing surfaces
6) Reassemble the valve and perform pressure testing
After maintenance, confirm:
1) No leakage
2) Stable opening and closing
3) Proper sealing performance
Important Maintenance Precautions
To ensure safe maintenance operations, avoid the following mistakes:
Never Change Spring Direction Randomly
Spring orientation directly affects:
1) Opening pressure
2) Closing speed
3) Valve performance
Incorrect installation may cause valve malfunction.
Never Disassemble Under Pressure
Disassembling a pressurized check valve can cause:
1) Sudden media release
2) Serious injury
3) Equipment damage
Always isolate and depressurize the pipeline first.
Never Use Valves Beyond Their Rated Service Conditions
Highly corrosive or abrasive media require specially designed check valves. Using unsuitable valves will significantly shorten service life and increase maintenance costs.
Conclusion
Check valve failures can lead to serious operational problems, including backflow, water hammer, leakage, and equipment damage. Understanding common failure symptoms and applying proper troubleshooting methods can greatly improve pipeline reliability and reduce downtime.
Whether you use swing check valves, lift check valves, wafer check valves, or silent check valves, regular inspection and correct maintenance are essential for long-term performance.
Choosing the correct industrial check valve and following proper maintenance procedures will help ensure safe and efficient pipeline operation.
