- Flange typeFlat
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.
Flanges steel flat welded GOST 12820-80
Note: GOST 12820-80 is superseded by GOST 1255-67, GOST 9938-62, GOST 12827-67 and GOST 12828-67. The present standard extends to steel flat welded flanges of pipelines and connecting parts, and also to connecting flanges of fittings, connecting parts, cars, devices, branch pipes of devices and tanks on the conditional pressure of Py from 0.1 to 2.5 MPas (from 1 to 25 kgfs / cм 2) and temperature of Wednesday from 203 to 573 To (from minus 70 to plus 300 C).
In pipelines flange connections are applied or when it is required to have demountable the pipeline, or in cases of connection of the pipeline to flange fittings, flange measuring devices and the equipment having a flange. A flange - the pipeline detail intended for installation of its separate parts, and also for accession of the equipment to the pipeline. Flange connection consists of flanges, laying, bolts or hairpins with nuts and washers. Laying is established between two flanges, contracts and flattened out zatyagy hairpins or bolts. Depending on the requirement to tightness (reliability of work) of flange connection and parameters of the transported environment flanges have various design of a sealing surface (flat, with a ledge and a hollow, etc.) Density of flange connection depends on laying prileganiye degree to a mirror of a flange and a design of a sealing surface. In pipelines flanges with sealing surfaces are applied: flat, with a connecting ledge, with a ledge or a hollow, a thorn or a groove, and also under gear laying. Depending on the conditional pressure and temperature flanges differ on type, the connecting sizes and material. The connecting sizes of flanges on the outer diameter, dimayetra of the centers of bolted openings, and also quantity of these openings and their diameters irrespective of whether the flange is released by a separate detail, it is cast together with the case of the equipment or fittings depending on conditional pressure, are identical and answered the sizes with the provided GOST 12820-80.
With a pressure no more than 4 MT installation of flat flanges is allowed. In other cases have to flanges welded end-to-end and the having sealing surfaces with a ledge or a hollow will be applied.