Can plate-type face weld flanges be used on natural gas pipelines? If not, which standard specifies this?
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Can plate-type face weld flanges be used on natural gas pipelines? If not, which standard specifies this?
Gas pipelines can use plate-type flat welding flanges, but pipe flanges of grade 16 kg or higher are required, along with non-metallic gaskets and fasteners of special grade, with specified tightening torques.
The above conclusion can be drawn based on the scope of application of flanges specified in HG/T20592 and the regulations for selecting flange gasket fasteners.
SHT3059 7.3.1 c) Plate flat welding flanges shall not be used for pipelines carrying toxic or flammable media
This is related to the pipe flange standards required by the project. From the perspectives of sealing principle and stress, the requirements specified in SH/T3059 are too stringent; those specified in HG/T20592 are more reasonable.
The TSGD-0001 Code for Safety Inspection of Pressure Piping states that flat-welded flanges cannot be used in conditions of severe vibration; it isn’t mentioned anywhere else, is it?