Stud-bolt length and specification for pipe flanges — HG/T 20592 (PN) and HG/T 20615 (Class). Lengths are taken from the standard LZR tables; select the sealing face to switch between RF and FF variants.
LZR = stud-bolt length for raised-face (RF) flange. For PN standard, the bracketed value is the flat-face (FF) variant. 'N' = not applicable.