Engineers need to select the right connection hardware to ensure a secure seal when assembling piping systems. An RFSO flange is a common choice for these applications.
The abbreviation RFSO stands for “Raised Face Slip-On.” This specific “Slip-On” design allows the component to slide directly over the end of the pipe before being welded in place. The raised face part of the flange concentrates the pressure load onto a smaller gasket area, improving its sealing capabilities when compared to a flat-face flange.
There are several different ratings or “classes” for these flanges; the higher the class, the higher the pressure rating, with class #150 being the lowest and most commonly used rating. These components are generally preferred for low-pressure applications where easy alignment is needed during installation.
RFSO Flanges are a type of pipe flange on the edges of expansion joints in which the bolting circle face is slightly elevated. Moreover, as a slip-on flange, it can slide over the pipe to provide a better seal and protect against leakage. This is best used in low-to-moderate pressure applications, and is preferred in situations where welding access is easier and lower-cost fabrication is desired.