Issues regarding the installation of graphite wound gaskets
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Whether it is for pipe flanges, vessel manway flanges, or metal-graphite wound gaskets on vessel shell flanges, should they be installed directly or after applying sealant to the gasket? If the flange sealing surface develops rust after many years of use, and the rusting is mild, is it better to apply sealant to the gasket? What should be done if the flange sealing surface is severely corroded?
There’s no need for a new sealing surface; if there is slight rusting later on, it’s fine to apply sealant or wrap some tape when replacing the gasket! If the damage is severe, the flange must be replaced or the sealing surface repaired
The corrosion is severe; to repair the sealing surface, the flange has to be cut off and then repaired using a lathe. This is a very complicated process. Is it possible to carry out the repair without cutting the flange?
For the first question, no glue is used. For the second question, no sealant is needed, as slight rust on the gasket can be compensated for. If the flange is severely corroded, there are several approaches: it can be replaced, the sealing surface can be processed directly with a pipe cutter to allow continued use, it can be filled with a special filler material; in less severe cases, sealant can be applied, or the flange can be rewelded after the sealing surface is leveled
Additionally, for flanges on larger-diameter container cylinders, if the sealing surfaces are still new, is it necessary to apply sealant to the metal-graphite wound gaskets?
Install it directly; after cleaning off any mild rust, check that the surface is smooth before installation. In cases of severe rust, the flange needs to be repaired
We install them directly; the gasket itself has a certain degree of flexibility, so there’s no need to add silicone as well； Actually, I don’t quite understand your question. If the flange is in use for a long time, the sealing surface will not suffer from severe corrosion ； If it’s a new installation, then there’s no need to cut it out ； Besides, if the requirements are high and there’s no dedicated test for the flatness of the flange, would you still dare to use it?
How to repair flange sealing surfaces online? Could you provide a detailed introduction?