Technical characteristics of flanges:
Flanges have to be produced with sealing surfaces of executions 1., 2., 3, and connecting sizes in accordance with GOST 12815-80. Production of flanges with sealing surfaces of executions 4 is allowed., 5., 8. and 9. An identification number at the order of a round steel flat welded flange of Dy of 50 mm for Py of 1.0 MPAS (10 kgfs/cm2) from steel 25, execution 1 (with a connecting ledge):
Maximum deviations of the sizes: Dn-on H 14 (when receiving by stamping - on class state standard specification 7505-98) Yu and also produced by method are flexible b-for stamped flanges from strip hire with the subsequent welding of a joint and is hotter a rikhtovka - on GOST 7505-89 T4 accuracy class. At the same time strengthening of a seam which when determining maximum deviation is not considered Flanges flat steel GOST 12822-80 is allowed
The present standard extends to steel flanges of pipelines and connecting parts of cars, branch pipes of devices and tanks, free on a welded ring, on Py from 0.1 to 2.5 MPas (from 1 to 25 kgfs/cm2) and temperature of Wednesday from 243 to 573 To (from minus 30 to plus 300 C).
Rings have to be produced with sealing surfaces of executions 1., 2., 3 and connecting sizes in accordance with GOST 12815-80. Production of rings with sealing surfaces of executions 4, 5, 8 and 9 is where technically justified allowed.