Different types of flange faces are used as the contact surfaces to seat the sealing gasket material. ASME B16.5 and B16.47 define various types of flange facings, including the raised face, the large male and female facings which have identical dimensions to provide a relatively large contact area.

Flat face (FF) flanges are similar to the RF flanges, but they do not have the raised area like the RF flange. Instead, the whole surface is flat. That means that the gasket used with the FF flange has full contact with the whole surface where two flanges are mated.

Learn about types of flange faces: Flat Face (FF), Raised Face (RF), Ring Joint (RTJ), Tongue and Groove (T&G), and Male and Female types.

ASME B16.5 Flat Face Flange belongs to the ASME B16.5 standard. This standard covers flanges of different material grades that range from ½ inches to 24 inches in diameter. Their pressure capacities vary from class 150 to class 2500.

A flat face (FF) flange is a type of flange where the gasket surface is flat and covers the entire flange face. This design contrasts with raised face (RF) flanges, where the gasket surface is elevated above the bolting circle face.

Mar 28, 2025 · Flat face (FF) pipe flanges are characterized by their smooth, even surface without any protrusions. To ensure a secure and proper seal, they are paired with non-metallic gasket. This gasket provides full contact across the entire flange surface, spanning from its inner diameter to outer diameter.

Dec 12, 2024 · FF flanges require full-face gaskets to distribute pressure evenly, whereas RF flanges concentrate pressure on a smaller gasket area, leading to potential issues.

Apr 20, 2021 · Flanged butterfly valve has a flange on the valve, and bolts are used to connect the flanges at both ends of the valve to the pipe flange. Do you know all the 7 types of flange sealing surfaces?

Flat face (FF) flanges use non-metallic gaskets (soft gaskets) and should always have a serrated sealing surface. This type of flange is well suited to low pressure applications and is used for pressure classes 125 and 250.

What is Flat Face Flange? A flange with a simple surface or a Flat Face flange (FF) is one of the types of flanges that are used in the connections of pipes and industrial piping systems. Flanges are also available with other internal disc surface types.