Q:What are common problems with check valves and how can they be avoided?

Check valves are generally simple and reliable components, but improper selection, installation, or operation—especially in demanding environments—can lead to performance issues and even system failure. Common problems include leakage, reverse flow, noise, vibration, sticking of internal parts, and wear caused by frequent cycling or fluid conditions.

These issues can be significantly reduced by choosing the appropriate valve type for the application—such as spring-assisted or non-slam check valves—and ensuring proper installation, flow direction, alignment, and maintenance. Doing so helps maintain system safety, minimizes pressure shock or energy loss, and extends the service life of both the valve and the pipeline system.

1. Reverse Flow / Backflow
Problem: Valve fails to close completely, allowing fluid to flow backward.
Causes: Worn sealing surfaces, debris stuck on the disc, damaged springs, incorrect installation.
Prevention:
Ensure proper valve orientation and flow direction.
Use strainers/filters to prevent debris entry.
Regularly inspect seals and springs for wear.
2. Water Hammer
Problem: Loud banging noise and pressure surge in the pipeline when the valve closes suddenly.
Causes: High fluid velocity, long pipeline runs, slow-closing check valves.
Prevention:
Use spring-assisted or non-slam check valves.
Maintain recommended installation distance (5–10 pipe diameters from pumps or elbows).
Control fluid velocity.
3. Valve Flutter or Chattering
Problem: The disc repeatedly opens and closes rapidly.
Causes: Low or unstable flow, oversized valve, wrong cracking pressure.
Prevention:
Select a valve sized for actual flow, not pipe size only.
Use a valve with proper cracking pressure.
Maintain steady flow conditions when possible.
4. Wear, Corrosion, and Erosion
Problem: Damage to discs, hinge pins, body, or seat surfaces.
Causes: Abrasive particles, corrosive fluids (seawater, wastewater, chemicals), cavitation.
Prevention:
Choose suitable valve materials (e.g., stainless steel, duplex, rubber-lined or coated type).
Use corrosion-resistant coatings or full rubber-lined check valves.
Install upstream strainers to remove solids.
5. Sticking or Blocked Disc
Problem: Valve cannot open or close fully.
Causes: Dirt, sediment, biological fouling, rust buildup.
Prevention:
Regular maintenance and cleaning.
Use anti-fouling designs/materials in seawater or wastewater systems.
Ensure clean fluid supply or add filters.
6. Incorrect Installation
Problem: Misalignment, leaks, or failure to operate.
Causes: Wrong flow direction, no gasket, over-tightened bolts, improper distance from elbows/pumps.
Prevention:
Always follow manufacturer installation guidelines.
Install between flanges evenly (for wafer type).
Maintain straight pipe runs before and after the valve.