What is the difference between flange adaptor with jointing face with o-ring groove and the flange adaptor combined jointing face flat and serrated, and when we use each flange? - Quora
HFL- Flange NH MALE Adapters: STRAIGHT- MADE IN USA - Hydrant Storz
Flat Face Flange Storz Adapters: 30 DEGREE ELBOW - SOS Safety
Lap-joint flange 150LB | Fitting Service
Ductile Iron Vs. Steel Flanges – Are They Interchangeable? - McWane Ductile - Iron Strong
Flange Faces - Raised Face (RF), Flat Face (FF), Ring-Type Joint (RTJ), Male-and-Female (MF), Tongue-and-Groove (TG)