Check Valve Replacement Timing and FAQs
When to Replace a Check Valve?
Service Life and Regular Inspection
Normal service life: High-quality check valves (such as those manufactured by PPR) are typically used for 5-10 years but need to be evaluated according to the operating environment.
Shortening service life in Harsh Environments: In humid environments, high temperature differences or environments containing corrosive agents, inspections are recommended every 3 to5 years and replacement if necessary. For example, kitchen check valves may require to be replaced more frequently if they are exposed to grease and smoke for long periods of time.
Performance Degradation: If poor sealing performance (e.g., leakage), inflexible opening and closing (e.g., jamming), corrosion resistance, etc., should be replaced in a timely manner.
Major Fault Signals
Backflow: The return of a kitchen odors or gas may be caused by a check valve failure.
Significant damage: cracked valve body, disc distortion or aging seal (e.g. hardened and cracked rubber rings).
Excessive Repair Costs: If repair costs are close to or exceed the price of a new valve, direct replacement is recommended.
Compulsory replacement in Special Scenarios
System upgrade: When piping is upgraded or equipment replaced, check valve should be replaced at the same time to ensure compatibility.
Safety Hazards: gas pipeline check valves leakage may cause explosion, require to be replaced immediately.
II. FAQs and Solutions
Leakage Problems
Reasons: aging seal, improper disc/seat installation, cracked valve body.
Solutions:
Replace seals (e.g., rubber rings, graphite gaskets) to ensure model compatibility.
Grind disc and seat sealing surfaces to repair scratches or deformations.
Check valve body integrity and replace any damaged valves.
Opening/ closing
Causes: impurity blockage, valve disc deformation, or wear of guide rail components.
Solutions:
Remove valve and remove internal sediment (e.g. welding slag, rust).
Correct or replace deformed disc and repair guide sleeve.
Apply lube (oil) to moving parts (e.g. stem).
Too much noise
Reasons: excessive media flow rate, poor valve selection, or installation problems.
Solutions:
Optimize pipeline design to reduce flow (e.g. increase pipe diameter).
Reassess valve model and replace check valve suitable for operating conditions (e.g. silent check valve). Check that the direction of installation is consistent with the direction of the medium and avoid reverse installation.
Valve failure (unable to close/ open)
Reason: Spring fracture, disc and seat misalignment, or medium pressure abnormality.
Solution: Replace spring or disc to adjust the valve seat coaxiality.
Check if upstream pressure exceeds the valve's rated value (PN). Install relief valve if necessary.
For vertical check valves, make sure the media flow is ``bottom to top ''.
Vibration and Water Hammer
Reason: Pulsating flow (e.g. near pump outlet) or valve closing too quickly.
Solution: Stay away from pump outlet (recommended distance ≥ 5 times pipe diameter) and avoid installation near throttle valves.
a water hammer eliminator downstream were installed downstream of large diameter pipelines (DN≥200).
Choose to close check valve slowly to reduce closing impact.
III. Maintenance Recommendations
Daily cleaning
Kitchen/Bathroom Check Valves: Remove and wash every 1-2 months, using a soft brush to remove oil or dust.
Industrial check valve: internal impurities are removed and polished every 1-2 years.
