This standard specifies the general rules for the selection of steel pipe flanges, gaskets and bolting (C1ass designated).
This standard is applicable to the steel pipe flanges, gaskets and bolting specified in HG/T 20615- HG/T 20634.
2. Normative references
The following standards contain provisions which, through reference in this text, constitute provisions of this national standard. For dated reference, subsequent amendments (excluding amending error in the text) to, or revisions of, any of these publications do not apply. However, parties to agreement based on this standard are encouraged to research whether the latest editions of these references are applied or not. For undated references, the latest edition of the normative document is applicable to this national standard.
