Lug-type butterfly valve connection issues
Thread Content
Lug-type butterfly valve flange, large diameter of 20 inches; four of the holes are threaded counterbored while the others are through-holes. Why is it designed this way? Wouldn’t it be fine if they were all through-holes, or all threaded holes? Through-holes don’t seem to be useful at all, do they? If there are threaded counterbore holes on both sides, just connect it directly to those threaded counterbore holes.
There are standards for flange openings; it’s not possible to drill them however one wishes. The drilling of the flanges is carried out in accordance with the pipeline design standards provided by the customer’s design engineering company.
Are these four counterbore holes there for easier disassembly? ? ?
This is mainly because the upper and lower ends are where the valve stem passes through; after the valve is assembled, the valve stem will block those openings, so they can only be designed as threaded holes. I hope you can understand my explanation.
We are a butterfly valve manufacturer; generally, all holes in the lug-type design are threaded holes, and through-holes are used only if requested by the customer