How to choose the flange type?
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Flange type (PL, SO, WN. . ) What is used to make the choice? Flange sealing surface type (raised face, serrated face, fully flat face). . . ) And what is used to make the choice? Who can describe it?
The choice of flange type depends mainly on the medium pressure; for general chemical media, WN and FL/SE are typically selected.
The form of the sealing surface is determined by the process or piping specialists, with the choice being made primarily based on pressure conditions and the properties of the medium. For reference, see also the table of seal surface types on page 21 of HG20592
Generally, for pipelines carrying media with low pressure, that are non-toxic and non-flammable, plate face weld flanges, threaded flanges, flat weld flanges, and socket weld flanges are used, with the seal surface type being either full flat or raised； Conversely, for high-temperature and high-pressure, toxic, flammable, and combustible media, butt weld flanges are used, with the sealing surface taking on a ring shape or a male-female design. The specific selection criteria can refer to HG20592~20635.
Search the forum to see if there is a flange selection manual
When choosing a sealing type, pressure is the primary factor to consider, followed by the medium, and then factors such as temperature.
For each project, the piping specialty prepares a pipeline grade table based on the process conditions, such as medium temperature and pressure. Each grade specifies the materials, grade numbers, end faces, connection types, as well as the standard codes (American standards, national standards, or petrochemical standards) applicable to pipes, fittings, valves, flange bolts, and gaskets. Refer to \"Design of Petrochemical Pipelines\", P22, compiled by Cai Erfu