This standard specifies the type and size of integral cast copper alloy flanges with nominal pressure PN of 0.6, 1.0, 1.6, 2.5, 4.0 and 2.0, 5.0 MPa. This standard applies to integrally cast copper alloy flanges with a nominal pressure of PN0.6 to 5.0MPa and a nominal diameter of DN10 to 1800mm.