1. There are currently four flange standards in China, which are:
(1) National flange standard GB/T9112~9124-2000;
(2) Chemical industry flange standard HG20592-20635-1997
(3) Mechanical industry flange standard JB/T74~86.2-1994;
(4) The flange standard for the petrochemical industry SH3406-1996
Taking the national standard as an example, explain the selection of flanges. The national standard flange is divided into two major systems: the European system and the American system. The nominal pressures of European system flanges include: PN0.25, PN0.6, PN1.0, PN1.6, PN2.5, PN4.0, PN6.3, PN10.0, and PN16.0MPa; The nominal pressures of American system flanges include PN2.0, PN5.0, PN11.0, PN15.0, PN26.0, and PN42.OMPa
2. The basis for selecting flanges
(1) The properties of the conveying medium, including general medium, special medium, toxic medium, flammable and explosive medium;
(2) Based on the parameters of the medium, working pressure, and working temperature, when the medium is determined, the nominal pressure PN of the flange is determined based on the working temperature and pressure of the medium.
(3) Determine the connection method and sealing surface form between flanges and pipes based on the usage location and connection conditions.
(4) Determine flange specifications based on the connection object.
Post time: Feb-28-2024