Hole is a through hole on the flange surface?

If the end is threaded on both sides of the blind hole, and not in the same circumference, whether the flange, why?

Answer:

Flange connection or flange connection, is defined by the flange, gasket and bolt connection between the three sealing structure of the detachable connection as a combination of group pipe flange refers to the pipeline installation of piping flange, used in equipment refers to equipment import and export flange.

Flanges in the narrow senseFlange (Flange), also called flange or flange plate. The flange is the part that connects the pipe to the pipe and is connected to the end of the pipe.

The flange is lined with bolts to secure the two flanges. Gaskets for gaskets between flanges. Flange, threaded connection (wire), flange and welding flange.Flange connecting has threaded hole, also is not uniform in the same circumference, mainly to see the effect, whether for connection;