Flange gasket
Thread Content
In chemical industry standards, some gaskets come with an outer ring and an inner ring. What are the advantages of this? What is the difference between them? How should one choose when selecting such gaskets? ?
The gaskets in the full inner and outer ring configurations can withstand higher pressures than those with only an outer ring, but one cannot rely on visual differences to determine this in practice. Check the pressure indicated on the gasket.
These issues are explained in detail in HG20583; you might want to take a look.
HG20583-1998 _ Code for Structural Design of Steel Chemical Vessels – I have uploaded it to the documentation area.
The selection is mainly based on different pressure levels.
It is determined based on the shape of the flange surface whether to use an outer ring or an inner ring. Raised-face flanges should be selected with an outer ring, while recessed-face flanges should be selected with an inner ring.
If conditions permit, it’s best to have the inner ring as well. Without an inner ring, the winding gasket tends to come apart easily during tightening. In such a case, the winding material may be carried into the pipeline by the force of airflow, potentially damaging valves or other equipment.
It is necessary to take into account factors such as pressure rating, flange type, and the properties of the medium. Of course, this is an exchange of experience; for more detailed requirements, relevant documentation can be consulted.
Choose the specific flange sealing type based on different pressures