GB-T_9116.1-2000 flanges can be interchanged with HG 20594-97 flanges

Currently, there are four types of flange standards in use in our country: **national standards (GB/T9112~9124-2000), chemical industry standards (HG20592~20635-1997), petrochemical industry standards (SH3406-1996), and machinery industry standards (JB/T74~86.2-1994).** Although the four types of flanges mentioned above differ in terms of standard grades and industries to which they are applied, the standards they follow are all ISO 7005-1, DIN flange standards, and ANSI B16.5 (petrochemical standards include ANSI 16.47). Only the mechanical flanges use the former Soviet ГОСТ flange standards, which still belong to the European flange system; therefore, there is a high degree of interchangeability among these standards as well as among standard flanges. The GB/T9112~9124-2000 series of standards for **steel pipe flanges are based on the use of the HG20592~20626-1997 standards in the chemical industry, which deal with steel pipe flanges, gaskets, and fasteners. The advantages of those standards have been incorporated into these new standards, whose overall structure has been improved to be consistent with or equivalent to that of the standards used in the chemical industry. Petrochemical industry standards are interchangeable with national standards, as well as with flange dimensions belonging to the American system in national standard flanges. Flange sizes belonging to the European system (Series II) in mechanical industry standards and national standards are interchangeable, but there are three flanges in mechanical industry flange standards that cannot be interchanged with national standards: PN0.25MPa–DN500, PN0.6MPa–DN500, and PN1.0MPa–DN80, due to differences in the number of bolts. It can be seen that the standard levels and dimensions of chemical industry standards are basically consistent with those of national standards, allowing for interchangeability of dimensions. Therefore, it is entirely feasible to manufacture valves according to national standard flanges and to use flanges specific to the chemical industry during installation.

Check the specific dimensions; if they are the same, they can certainly be swapped

It’s best to remember it; if not, just look up the relevant standards and check the dimensions – that’s fine. There are no standards in the world originally, but once many people use something, it becomes a standard.

Yes, as long as all the corresponding dimensions are the same. . . However, the author’s “FR” should probably be “RF”. . . :lol