Selection of flange gaskets when installing instruments
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Hello everyone, we are working on an instrumentation project for a factory, where many of the instruments are connected to tanks/pipes via flanges. When selecting flange gaskets, I follow the principle of using the same type of gasket as that used for the main pipes in the process. There are a few detailed questions I would like to ask everyone. 1. Are the principles I mentioned just now appropriate? 2. There are polytetrafluoroethylene gaskets and tetrafluoroplastic gaskets used in manufacturing; are these two the same? What’s the difference? 3. Some gaskets are made of soft PVC. What are the characteristics of these gaskets compared to the ones mentioned above? 4. It has been mentioned in some places that PTFE gaskets are not suitable for non-metallic connections; our flanges are not made of metal. Is there a better alternative? Waiting online, thank you all.
Gaskets made of polytetrafluoroethylene and tetrafluoroplastics are actually the same thing; it’s just that they have different names. The gaskets made of PVC are made of polyvinyl chloride, and they do not possess the heat and pressure resistance of PTFE. Teflon can be used for both metal and non-metal connections, depending on the medium and the pressure rating of the equipment; equipment with a high pressure rating can use teflon, while those with a lower pressure rating can use polyvinyl chloride
These days, metal wound gaskets are mostly used as they are very convenient to use. One only needs to specify the flange size and then indicate the material type.
In fact, PTFE and PFA are not the same thing; there seem to be no gaskets made of fluoroplastics, as fluoroplastics are used for lining purposes.
Your principle is correct. However, the selection of gaskets is closely related to the properties of the process medium, pressure, temperature, as well as the connecting flanges. The selection of flange gaskets is an area that poses challenges for the instrumentation field, requiring particular care. It is recommended to consult technical personnel or designers in the field of process engineering around you, or to refer to the specifications or standards related to pipe flanges used in the process pipelines of this project.
I’ve learned something; thank you all. I basically understand it now; after checking the standards and discussing it with the technical team, a decision was finally made. Hehe.