1. Expected life range and core influencing factors
The expected life of a check valve is usually 5-15 years, which is determined by the following factors:
Material differences:
Cast iron material: Strong corrosion resistance, life can reach 10-15 years under normal working conditions;
Carbide cladding valve disc (such as cobalt-based alloy): Wear-resistant and high-temperature resistant, life can be extended to more than 12 years in high-pressure scenarios of petroleum and chemical industries;
Plastic material: Easy to age and become brittle, life is about 5-10 years, high temperature and strong corrosive environment should be avoided.
Use environment:
Clean medium (such as water, steam): life is close to the upper limit; Particle/corrosive medium (such as mud, acidic liquid): internal wear is accelerated, life may be shortened to 5-8 years; Pressure and temperature fluctuations: High pressure (≥1.6MPa) or high temperature (＞80℃) scenarios require enhanced design, otherwise the life is reduced by 30%-50%.
II. Comparison of the lifespan of different types of check valves Swing check valve:
Structural advantages: The valve disc rotates around the axis, and the flow resistance is small, which is suitable for scenes with large diameter (DN≥200) and impurity-containing media; Life performance: The conventional design life is 8-12 years, and it can reach 15 years when using a carbide valve disc and auxiliary spring/weight structure.
Spring check valve:
Core limitation: Spring is a vulnerable part, and the life of ordinary compression spring is about 500,000-500,000 opening and closing cycles (about 3-5 years in home scenarios;
Enhancement solution: Use special alloy springs (such as high carbon steel + surface coating), the life can be increased to 2 million times, but it needs to be replaced regularly;
Comprehensive life: The life of the valve body is about 10 years, but the spring needs to be checked and replaced every 1-2 years, otherwise the sealing performance will be greatly reduced.
III. Key maintenance measures to extend the life
Regular inspection:
Check the valve disc wear, sealing surface integrity (swing type) and spring elasticity (spring type) every 1-2 years;
The system containing particle media needs to increase Filter device, reduce scouring inside the valve.
Installation optimization:
When the swing check valve is installed vertically, it relies on gravity to close, and it is necessary to ensure that the valve disc is not blocked;
Spring check valves should avoid horizontal installation deviation to prevent spring fatigue caused by unilateral force.
Working condition matching:
For high-pressure scenarios (≥1.6MPa), carbide valve discs or special spring designs are preferred;
For high-temperature environments (＞80℃), heat-resistant rubber seals or metal-to-metal sealing structures are required.
IV. Typical scenario life reference Municipal water supply pipelines (swing cast iron valves): about 12-15 years; Household independent heating system (spring check valve): valve body life 8-10 years, springs are replaced every 3 years; Chemical high-pressure pipelines (H44H swing carbide valves): 10 years or more, the sealing surface needs to be checked every year