These flanges as shown in ANSI B16.1 are largest, thicker and possess different bolt circles and may have more bolt holes. They cannot be joined to Class 125 Flanges. They are rated for 250 psi working pressure.
NOTE: Class 250 flanges have raised faces. If Class 250 flanges have raised faces, they should not be mated with flat faced Class 250 flanges.
Loose Flanges
Flanged pipe fabricated in accordance with these standards requires facing after machine tightening (ANSI/AWWA C115/A21.15 Section 15-9.2). It is therefore not recommended that flanges be ordered with flanges loose for field completion.
Threaded Mechanical Joint Adapters
Currently many fabricators provide threaded on mechanical joint bells in lieu of static castings. These bells are produced form dimensions provided by ANSI/AWWA C111/A21.11 and are threaded in accordance with ANSI/AWWA C115/A21.15.
