Why do flange holes need to be processed after hot-dip galvanizing flanges?

After hot-dip galvanizing, flange holes still need to be processed, mainly based on three requirements: ensuring sealing performance, optimizing anti-corrosion effect, and improving connection reliability. The specific analysis is as follows:

1、 Ensure sealing performance and prevent medium leakage

The flange hole is a critical part of pipeline connection, and its sealing performance directly affects the operational safety of the system. If there is zinc layer accumulation or burrs on the edge of the flange hole after galvanizing, it will cause the sealing surface to be uneven, making it difficult for the gasket to fit tightly with the flange, thereby causing medium leakage.

2、 Optimize anti-corrosion effect and extend service life

Although the hot-dip galvanized layer itself has excellent anti-corrosion performance, if there are zinc layer defects (such as uneven thickness, pores, etc.) at the edge of the flange hole, it will become the starting point of corrosion. Post galvanizing treatment can eliminate these defects and improve the anti-corrosion effect

Fate.

3、 Improve connection reliability and meet operational requirements

The treatment of flange holes also involves ensuring connection strength. If there are burrs or unevenness on the edge of the flange hole after galvanizing, it will exacerbate wear during installation and reduce connection reliability.