What are the replacement standards for threaded quick-insert fittings?

1. Sealing judgment standards
According to the requirements, the leakage of thread type push-in fittings in the disconnected state should be ≤318mL/time. If the actual leakage exceeds this threshold, it indicates that the seal ring is aging or the valve core is deformed, and it needs to be replaced immediately. If oil leakage is found in the pipeline interface or the pressure of the air pressure system is abnormally attenuated during continuous operation, the integrity of the seal ring and the thread matching accuracy need to be checked. If the seal ring is cracked, hardened or the compression permanent deformation is greater than 30%, it must be replaced.

2. Structural integrity standard
If the thread wear causes the screwing clearance to exceed the standard, such as the wear of the outer thread middle diameter greater than 0.1mm or the cumulative error of the pitch exceeds the tolerance, it needs to be replaced. If cracks or broken teeth appear at the root of the thread, it should be replaced even if there is no leakage to avoid the risk of breakage. If plastic deformation, cracks or deviations in the flatness of the flange surface are observed in the metal shell, the threaded quick-insert fitting needs to be replaced.

3. Environmental and working condition adaptability
If the joint material reacts chemically with the medium, or the material strength decreases by more than 30% in a high temperature environment, the joint needs to be replaced with a suitable material. For joints exposed to salt spray environments (such as coastal areas), if the coating shedding area is greater than 5% or the corrosion depth is greater than 0.05mm, stainless steel (such as 316L) or chrome-plated models need to be replaced.