What gaskets are used for natural gas pipeline flanges?
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Common gasket types used in natural gas pipelines include polytetrafluoroethylene gaskets, metal wound gaskets, reinforced graphite gaskets, and asbestos-free gaskets. Recent airtightness tests on these gaskets have shown that metal wound gaskets and PTFE gaskets provide the best initial sealing performance. However, metal wound gaskets are too expensive, so they can only be used in part to reduce costs. PTFE has the problem of cold flow, while graphite gaskets require a high torque to prevent leaks, resulting in low installation efficiency. I also tried PTFE-coated gaskets and non-asbestos gaskets. The PTFE-coated gaskets performed very well: they required low torque and were inexpensive as well. Yet, the natural gas industry hardly uses PTFE-coated gaskets; I’m not sure why Non-asbestos gaskets are inexpensive, but they suffer from significant leakage when not soaked in oil; on the other hand, using them only after soaking them in oil is too troublesome. Do any experts have any recommendations for non-asbestos gaskets that can be used without being soaked in oil?
This post was last edited by Desert Fish on 2020-12-19 at 12:12. Modified polytetrafluoroethylene material can be used to alter the material’s own creep and cold flow properties; we also have asbestos-free versions imported from abroad available. Please contact us if you need samples
Metal gaskets are the preferred choice, followed by modified polytetrafluoroethylene
First, there are metal wound gaskets; gaskets account for a small portion of the total cost. The price of high-quality RPTFE isn’t any lower than that of metal wound gaskets, and cheap ones still don’t provide proper sealing
Metal gaskets are the preferred choice; for non-metallic gaskets, the grounding resistance also needs to be taken into account, and if the resistance is too high, a bypass wire must be added. The effort and trouble aren’t worth it
Do you mean electrostatic bonding when you talk about cross-wiring?
Non-asbestos materials are not safe for use in gases; winding is the preferred method, and materials can be selected accordingly
Selection is made based on installation requirements and process parameters (temperature, pressure, corrosion, etc.)
Metal wound gaskets are the first choice, while polytetrafluoroethylene is the second choice