Flange Types
Slip-On Flanges
Cost-effective flanges that slide over the pipe for easy installation.
Slip-on flanges (also called SO flanges or hubbed flanges) have a bore slightly larger than the pipe outside diameter, allowing the pipe to slide through the flange before welding. Two fillet welds attach the flange to the pipe: one on the outside of the hub and one on the inside bore. The pipe typically extends approximately 1/8" past the flange face before the inside weld is applied.
Slip-on flanges cost less than weld neck flanges and are easier to align during installation, making them popular for general-purpose piping in Class 150 and Class 300 service. However, they develop approximately two-thirds the strength of a comparable weld neck flange and are not recommended for severe cyclic loading, high-pressure, or high-temperature applications where fatigue life is a concern.
Flanges.IO stocks slip-on flanges in sizes from 1/2" through 24" in pressure classes 150 through 600. Standard materials include carbon steel (A105), stainless steel (A182 F304/F304L, F316/F316L), and alloy grades. Raised face is the standard configuration, with flat face and RTJ available on request. Contact us for pricing and immediate availability.
