HT PIPE supply all different types and scales of flanges. Please feel free to contact us for further product information and pricing.
A slip-on flange is designed to slide over the outside diameter of the pipe. It is then welded both internally and externally (fillet welds) to provide strength and prevent leakage.
The Class 400 designation indicates the pressure-temperature rating of the flange. While less common than Class 150 or Class 300, Class 400 flanges are the go-to choice when a system's operating pressure exceeds Class 300 limits but doesn't quite require the massive wall thickness (and added cost) of a Class 600 system.
Key Dimensions for Class 400 Slip-On Flanges
Outside Diameter (O.D.): The total width of the flange disk.
Bore Diameter (I.D.): The inner diameter, which is slightly larger than the outside diameter of the matching pipe so it can slip on smoothly.
Thickness (Y): The total thickness of the flange, including the raised face. Class 400 flanges are significantly thicker than Class 150/300 to handle higher pressures.
Bolt Circle Diameter (B.C.D.): The centerline circle where the bolt holes are drilled.
Number & Diameter of Bolt Holes: Essential for selecting the correct heavy hex bolts and gaskets.
Application of Class 400 Slip-On Flanges
Oil and gas: submarine pipelines, downhole tools for acid gas wells.
Chemical equipment: sulfuric acid reactors, phosphoric acid evaporators, pickling equipment.
Nuclear industry: containers and pipelines for nuclear waste treatment systems.
Marine engineering: seawater desalination devices, heat exchangers.
Environmental protection: key components of flue gas desulfurization (FGD) systems.
ASME B16.5 Class 400 Slip-On Flange Dimension
