What Is a Flat Face Flange?

What Is a Flat Face Flange?

A Flat Face Flange, commonly known as an FF flange, has a completely flat sealing surface. Unlike a Raised Face flange, the entire flange face remains at the same level.

Flat face flanges are commonly used in piping systems where the connected equipment requires a full-face gasket.

Where Are Flat Face Flanges Used?

Typical applications include:

• Water treatment systems
• Low-pressure pipelines
• Cast iron equipment
• HVAC systems
• General industrial piping

The flat design provides full contact between the flange and gasket, helping distribute the bolt load across the connection.

Flat Face vs Raised Face

A Raised Face flange has a raised sealing area, while a Flat Face flange has a completely flat surface.

The choice depends on the connected equipment, pressure requirements, gasket type, and applicable piping standard.

Material Options

Flat face flanges can be manufactured from:

• Carbon steel
• Stainless steel
• Alloy steel
• Duplex stainless steel

Proper material selection is important for corrosion resistance, pressure performance, and service life.

As an experienced China steel flange manufacturer, we supply flat face flanges in different sizes, pressure ratings, materials, and standards for global industrial customers.