Material of the gate valve cover gasket
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I would like to ask everyone: are gasket materials for the large covers of gate valves usually asbestos or graphite? The large cover of a water valve in my installation is leaking; after removing the cover, I found that the gasket was made of asbestos. I’m not sure what material is generally used. Thank you
It is difficult to clean the gaskets during subsequent maintenance work involving asbestos; for low-temperature applications, PTFE gaskets work well, while for high-temperature applications, graphite gaskets are a good choice. It depends on the sealing groove – in some cases, internal ring wound gaskets may be used
The selection of gasket material depends on many factors, including operating conditions: pressure, temperature, and medium； The material, type, and roughness of the sealing surface, among other factors, should be considered comprehensively to select the appropriate material. Asbestos materials are being phased out gradually due to their harmful effects on humans and the environment, and they are being replaced by asbestos-free fiber compressed boards. Graphite gaskets are generally used in high- and low-temperature environments, while polytetrafluoroethylene is often used in low-temperature areas where corrosion resistance is required. And asbestos-free materials can be used under normal temperature, pressure, and medium conditions
Use asbestos-free gaskets; they are environmentally friendly
Use graphite gaskets as much as possible; polytetrafluoroethylene can also be used if the temperature is not high. As asbestos products are carcinogenic, do not use asbestos pads.
Graphite is the most expensive and offers the best results; PTFE was almost used instead
Metal-graphite wound gaskets are better.
I’m going to check the actual images of the relevant gaskets