What type of metal wound gasket is used for steam pipes?
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For superheated steam at 1 MPa and 320 degrees, which type of gasket should be used? For saturated steam at 0.6 Mpa, if metal wound gaskets are also to be used, which model would be suitable? There are too many combinations of metal wound gaskets, and I’m not very good at choosing the right one.
It should also be heat-resistant; I’m not exactly an expert on which specific model to use, so I’ll wait for answers from other sea users
It is described in HG/T20610/HG/T20631
For diameters equal to or less than DN600, gaskets with an outer ring are recommended; for diameters greater than DN600, gaskets with both inner and outer rings are advised. The technical recommendations are as follows: For superheated steam at 1 MPa and 320 degrees: in the American system, use wound gaskets made of 0Cr18Ni9+F.G., with an outer ring, of PN50 standard, in accordance with SH/T 3407 (or HG/T20631), with a thickness of 4.5 mm and a RF finish. For saturated steam at 0.6 MPa, use wound gaskets made of 0Cr18Ni9+F.G., with an outer ring, of PN20 standard, in accordance with SH/T 3407 (or HG/T20631), with a thickness of 4.5 mm and a RF finish
Steam pipes are generally fitted with \"304 + flexible graphite gaskets\"; \"asbestos-free fiber rubber gaskets\" can also be used, but they are not recommended.
The model of the gasket should be chosen based on the sealing surface of your flange; detailed information is available for 20610 and 20631, so it’s best to take a look for yourself.
This post was last edited by Liu Jiajia on 2017-3-28 09:28. 1. The type of winding gasket is related to the flange sealing surface; RF type uses a gasket with an outer ring or both inner and outer rings (inner and outer rings are used for DN＞600, and for pressure grades of CL600 and above, inner and outer rings are used for all diameters)； MFM face with inner ring ； Basic TG face. 2. The material combination of the winding gasket is related to its temperature resistance and corrosion resistance; details can be found in the gasket standards. 3. The pressure rating of the winding gasket should be the same as that of the flange. 4. The thickness of the winding pad is generally 4.5 mm. 5. The notation for the winding pad can indicate the material directly or use a code. Note that the coding conventions for SH/T3407 differ from those of HG/T20610 and HG/T20631: SH/T3407 uses a sequence from inside to outside, while HG/T20610 and HG/T20631 use a sequence from outside to inside. 6. The flange joint is a single unit; for the selection of flanges, gaskets, and fasteners, references such as HG/T20614, HG/T20635, and SH/T3059 can be consulted. For superheated steam at 1.0 MPa and 320°C, as well as saturated steam at 0.6 MPa, RF-faced flanges are generally used. Optional winding gaskets with an outer ring or both inner and outer rings; material 304+FG will suffice.
Last edited by Xueren Lai on 2017-3-29 14:18: Gaskets composed of 0Cr18Ni9 material plus flexible graphite, with metal wave-shaped teeth; suitable for DN600 and below, in accordance with petrochemical and American standards. Also available as gaskets made of 0Cr18Ni9 steel strip and flexible graphite strip, with an outer ring, for use under chemical industry standards; PN2.5 RF, HG/T20610, T=4.5mm
The selection of gaskets is primarily determined by the flange type; for temperatures and pressures up to 320°C, a standard metal-wound gasket is sufficient