What materials are generally used for gaskets in low-pressure steam systems?
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What materials are generally used for gaskets in low-pressure steam systems? Which gaskets are both effective and cost-effective?
Oil-resistant asbestos gaskets can be used economically
Metal-wound graphite gasket. Previously, asbestos gaskets were used in some places, but they aged and leaked shortly after. For steam, metal-wrapped graphite gaskets are used. Ah, it’s safer that way
Metal wound gaskets with rings are the best! However, some low-pressure steam systems can also use high-strength gaskets (flexible graphite gaskets). Therefore, for pipeline flanges operating at low pressures (≤1.6 Mpa) on a continuous basis, metal wound gaskets are not necessary; flexible graphite gaskets can be used instead. For pressures ranging from 1.6 to 5.0 Mpa, metal wound gaskets should be used. In the case of backflow situations where the system is not in use regularly, it is recommended to use metal wound gaskets, especially in winter, due to thermal expansion and contraction – using flexible graphite gaskets increases the risk of them being damaged!
The pad is wrapped with Xinhua graphite, allowing for free adjustment due to thermal expansion and contraction
Nowadays, metal wound gaskets are mostly used; in the past, ones cut from asbestos rubber sheets were used
If the steam pressure is not high and you want to save money, then use asbestos sheet gaskets. Of course, this works fine for pipes with small diameters, but for larger diameters it’s better to use metal wound gaskets – the consequences of using something else in that case aren’t trivial at all.
Asbestos gaskets are generally suitable for low-pressure steam systems, but metal wound gaskets are recommended as the preferred choice.
Most of the gaskets currently available use metal-wound gaskets; some, in order to extend their service life and reduce loss due to burning, utilize graphite paper with low burn rate. For the metal strips used, more corrosion-resistant materials such as 316 are employed. Other types include 304 graphite-reinforced gaskets and asbestos gaskets, which can be seen occasionally. For more environmentally friendly options, asbestos-free gaskets are used.
We use black asbestos gaskets here, and there’s no problem with that. For metal wound gaskets, I don’t think low-pressure steam is really necessary; of course, it’s best to use it if one can afford to.