December 13, 2024
A check valve, also known as a one-way valve, is an automatic valve that ensures that liquid or gas can only flow in one direction, effectively preventing reverse flow.
Valve leakage
Reason for malfunction:
Sealing surface damage: Impurities in the fluid wash, corrosion, or frequent opening and closing operations cause wear on the sealing surface of the valve disc and seat. For example, solid particles in sewage pipes are prone to scratching the sealing surface.
Aging of sealing materials: Poor quality or prolonged use of sealing materials can cause rubber and other sealing materials to age, harden, and deform. In high-temperature environments, the aging rate of rubber seals will accelerate.
Improper installation: During installation, the valve disc is not aligned with the valve seat, or the pipeline connection is not tight, resulting in stress that prevents the valve disc from tightly fitting the valve seat.
Solution:
Repair or replace sealing surface: Grinding repair can be carried out when the sealing surface is slightly worn, and the valve disc or seat can be replaced when it is severe. Professional grinding can be performed to check chemical pipeline valves.
Replace sealing material: When the sealing material ages, choose a suitable new sealing material based on the fluid properties and pressure. Polytetrafluoroethylene sealing materials can be chosen for high-temperature and highly corrosive fluids.
Reinstall the valve: If there is an installation error, reinstall it to ensure the pipeline connection is firm, the valve disc is aligned with the valve seat, and the installation direction is correct.
The valve cannot be opened normally or is not fully opened
Reason for malfunction:
Valve disc stuck: Impurities such as rust and mud can get stuck on the valve disc, or long-term disuse can cause the valve disc to adhere to the valve seat. Sediments are prone to accumulating in the unused water supply and drainage pipelines, leading to the valve disc of the check valve getting stuck.
Insufficient pipeline pressure: This occurs frequently in pipelines with erratic flow or inadequate power sources when the fluid pressure inside the pipeline is less than the pressure needed for the check valve to open.
Solution:
Clean up impurities inside the valve: When impurities get stuck in the valve disc, disassemble the valve for cleaning. Place filters in front of impurity-prone pipelines, such as filter screens in front of check valves for irrigation systems.
Check pipeline pressure: Determine the cause of insufficient pressure. If it is a power source issue, repair or adjust the source; if the pipeline resistance is high, consider optimizing the pipeline layout or increasing the pipe diameter.
The valve cannot be closed properly or is not fully closed
Reason for malfunction:
Valve disc damage: Excessive impact force or long-term wear can deform the valve disc, preventing it from closing tightly. This issue is likely to occur when the hydraulic system is shut down quickly.
Foreign object obstruction: The foreign objects in the fluid can become lodged between the valve disc and the valve seat. In pipelines transporting chemical raw materials, undissolved solid materials may disrupt valve closure.
Solution:
Repairing or replacing the valve disc: This involves handling it according to the extent of damage, reshaping it if it is somewhat bent, and replacing it with a new one if it is badly damaged.
Remove foreign objects: Disassemble the check valve to remove foreign objects while strengthening fluid filtration in the pipeline.
Conclusion
To put it briefly, knowing the typical problems with check valves and how to fix them is essential to guaranteeing regular operation, successfully extending their service life, and lowering operating risks and expenses.
