Summary of Flanges and Gaskets
In industrial pipeline connections, flanges play a vital role. From Episode 18 to Episode 21, we briefly sorted out the basic knowledge of flanges, laying a solid foundation for their correct selection and application.
Structure and Types of Flanges
Core Structural Forms
Flanges are not uniform. According to connection methods and application requirements, they are mainly divided into:
Welded Types:Plate-type flat welding flange、Neck-type butt welding、flange、Neck-type socket welding flange、Integral flange/long hub flange,Non-welded Types:Neck-type loose flange、Threaded flange.
BMCMulgraf：Good medium resistance and wide application range
Applicability
Each flange structure has its specific application scenarios. For example:Neck-type butt welding flanges are commonly used in high-pressure and high-temperature working conditions.Neck-type flat welding flanges are suitable for medium and low-pressure environments.Loose flanged flanges facilitate installation and disassembly.Threaded flanges are applied to special occasions with smaller diameters.Selection should comprehensively consider factors such as pressure, temperature, and medium characteristics.
Sealing Surfaces
Key Interfaces for Connection
The flange sealing surface is known as the "first line of defense against leakage", with different forms corresponding to different working condition requirements. The sealing effect of a flange depends on its sealing surface type, and common types are as follows:
FF (Full Face Flange Sealing Structure)
Used with full-face gaskets, generally suitable for low-pressure applications.
MFM (Male/Female Face Flange Sealing Structure)
The male and female grooves are used in pairs, and the gasket is embedded in the groove to prevent extrusion. It is widely applied in valve body covers and valve bonnets.
BMC Spiral Wound Gasket
RF (Raised Face Flange Sealing Structure)
The sealing surface is set on the raised boss, and various flat gaskets can be installed during this process.
TG (Tongue-and-Groove Face Flange Sealing Structure)
The sealing element is placed inside this groove. The tongue face is inserted into the groove face, and they need to be used in pairs for precise positioning.
RJ (Ring Joint Face Flange Sealing Structure)
It is mainly characterized by line sealing and is used with a matching metal ring gasket. It is generally used in high - temperature and high - pressure environments.
BMCRIN：Has excellent compression resilience and sealing capability
Type C/O Ring Face(Type C and Type O Ring Flange Sealing Structures)
For special sealing requirements.
Understanding the structure, type, and sealing face of flanges is the first step to ensuring the safe and reliable connection of pipelines. Next episode sharing: Content such as the standard system of flanges and gaskets and sealing stress.
Ingenious Seal Mastery
For sealing leakage issues, Baohua provides solutions. If you have any doubts about sealing technology, please pay attention to Suzhou Baohua and feel free to consult, comment, or leave a message! Thank you all! In the next episode, we will continue the summary of flanges and gaskets. See you next time!
Email：marketing@mybmc.com.cn 
