Summary of Flanges and Gaskets

In the previous episode, we briefly summarized the content of Episodes 18 to 21 and sorted out some basic knowledge of flanges. Next, we will continue to summarize the relevant content of flanges and gaskets, and explore the standards of flanges and gaskets, the sources of sealing stress and its direction of action in Episodes 22 to 25.

Standard Systems for Flanges and Gaskets

In engineering applications, following standards is crucial: These standards and specifications ensure the interchangeability of flanges and gaskets, enhance the reliability of sealing systems, and reduce the risk of leakage.

Domestic and Foreign Standards

The main standard systems for flanges and gaskets include foreign standards (such as ASME, DIN, JIS, etc.) and domestic standards (such as GB, HG, SH, JB, etc.).

This part focuses on the concepts of Nominal Diameter (DN/NPS) and Nominal Pressure (PN/Class), as well as their conversion relationships. It should be noted that the nominal pressure does not directly represent the allowable pressure of the medium. When selecting flanges, the relationship among the flange structure, sealing surface type, nominal diameter, and pressure range must be considered to avoid sealing failure or even safety accidents caused by improper selection.

Sealing Stress

Sources and Directions

Sustained and effective sealing stress is the primary condition to ensure reliable sealing. So, what are the sources of sealing stress?

BMCSE: It has a self-tightening function driven by the medium pressure.

1、Bolt Load
The initial clamping force generated by tightening the bolts, belonging to forced sealing.

2、Medium Pressure
The pressure of the medium in the system acts on the gasket, further compressing the sealing surface, belonging to self-tightening sealing.

3、Semi-self-tightening Sealing
Bolt load + medium pressure = semi-self-tightening sealing.

The direction of stress action is determined by the primary direction in which sealing stress is applied to the gasket, which helps us understand the design of sealing structures and sealing management.

Axial Sealing, Radial Sealing, Inclined Sealing

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!