5 Types Commonly Used Flange Faces

Flanges play an important role in connecting pipes, besides knowing the basic types of flanges, it is necessary to further understand the form and application of flange faces. In addition, since the specifications of flanges are very diverse, the standard classification of flanges also needs to be paid attention to when selecting them. The common flange standards will be introduced in the next article.

What are the commonly used flange faces?

1. Flat Face (FF): The smooth surface and simple structure make it easy to process the corrosion-resistant lining. Using full-face gasket to cover the entire flange sealing surface. Due to the large contact area between the sealing surface and the gasket, after pre-tightening, the gasket is easily moved to both sides and be squeezed out of the sealing surface. It is well suited to low pressure and low temperature applications. Flange gaskets are generally divided into metal gaskets and non-metal gaskets, flat face flanges use non-asbestos gaskets.

2. Raised Face (RF): The smooth surface and simple structure make it easy to process. Because of its easy installation, it is the most widely used type of flange employed in the oil and gas and chemical engineering industries. The contact surface of the gasket protrudes from the bolting circle face, concentrating the pressure on a smaller gasket area, thereby increasing the pressure containment capability. Applicable gasket materials include non-metallic flat-ring gaskets and metallic spiral wound gaskets and metal jacketed gaskets.

3. Ring Type Joint (RTJ): The metal ring is placed in the groove, and the gasket will not be pressed into the groove. The compression area is small, and the pressure of the gasket is uniform. When the bolt is tightened, the metal ring is compressed to form a tight seal. Because the gasket and the medium are not in direct contact, it can be used in applications with strict sealing requirements, such as high temperature and high pressure, flammable, explosive and toxic media. Ring type joint flanges use oval ring gaskets or octagonal ring gaskets.


4. Male and Female (MFM): It consists of a male face and a female face, which are used in pairs and are easy to align during installation. Placing the gasket on the female face can prevent the gasket from being extruded, so it can be used in applications with high pressure and strict sealing requirements, but it is not easy to replace the gasket. However, the gasket may still be squeezed out when the male and female flanges are used under high temperature operating conditions. Applicable gasket materials include non-metallic flat gaskets, metallic spiral wound gaskets and metal jacketed gaskets.


5. Tongue and Groove (TG): It consists of a tongue flange and a groove flange, which are used in pairs. The tongue flange is manufactured with a raised ring that is machined into its face, and the groove flange is produced with a matching depression machined onto its face. Placing the gasket in the groove flange, so the compression area is small, the gasket is uniformly stressed, and it is not easy to be extruded. Because the gasket is not in direct contact with the medium, the sealing effect is good, and it can be used in high pressure, flammable, explosive and toxic media, etc. Tongue and Groove flanges use metal and non-metallic flat gaskets, metallic spiral wound gaskets and metal jacketed gaskets.

The above is the basic description of the flange faces. When choosing the flange installed with the pump, it is recommended to consult with professionals before   select it.