GOST 12820-80 Slip On Flange

Steel Plate Welded Flange | PN 0.6–2.5 MPa

GOST 12820-80 slip on flanges are steel plate welded flanges designed for low to medium pressure piping systems.
Manufactured according to the Russian standard GOST 12820-80, these flanges are widely used in water supply, heating systems, oil & gas pipelines, and general industrial applications.

GOST 12820-80 flanges are commonly referred to as plate slip on flanges, offering simple installation, reliable sealing, and cost-effective performance for non-critical pressure services.

What Is GOST 12820-80?

GOST 12820-80 is a Russian standard that specifies requirements for flat welded steel flanges intended for pipelines operating at nominal pressures from PN 0.6 MPa to PN 2.5 MPa.

This standard defines:

• Flange dimensions and tolerances

• Pressure ratings

• Materials

• Marking and inspection requirements

GOST 12820-80 is commonly used together with GOST 12821-80 (weld neck flanges) in Russian and CIS region projects.

Flange Type & Design

• Flange Type: Slip On (Flat Welded Flange)

• Manufacturing Process: Steel plate cutting + welding

• Connection: Slip over pipe and welded on one side

This design allows easy pipe alignment and installation, especially suitable for large-diameter pipelines.

Pressure Rating

Nominal Pressure Range:

• PN 0.6 MPa

• PN 1.0 MPa

• PN 1.6 MPa

• PN 2.5 MPa

(Equivalent to approximately PN 6 / PN 10 / PN 16 / PN 25 in EN standards.)

Materials

GOST 12820-80 slip on flanges are commonly supplied in the following materials:

• Carbon Steel:

  • St20

  • St3

  • 09G2S

• Alloy Steel / Stainless Steel:

  • Available upon request

Material selection depends on design pressure, temperature, and service medium.

Dimensions & Size Range

• Standard: GOST 12820-80

• Nominal Diameter (DN): DN 10 – DN 2000

• Facing Type: Flat Face (FF)

• Bolt Holes: As per GOST specification

We are the profession manufacturer of Steel plate welded flanges by GOST 12820-80. 

Diameter nominal, DN, mm: 10-2400, 10-1600, 10-1200, 10-800 
Pressure, PN 0.1; 0.25; 0,6; 1,0; 1,6; 2,5 MPa
Materials: steel 3сп, 20, 25, 09Г2С, 10Г2, 15Х5М, 12Х18Н10Т,gost CT20 flange

ГОСТ 12820-80. Фланцы стальные плоские приварные на Ру от 0,1 до 2,5 МПа (от 1 до 25 кгс/кв.см). Конструкция и размеры (с Изменениями N 1, 2, 3, 4

ГОСТ 12820-80 Группа Г18 МЕЖГОСУДАРСТВЕННЫЙ СТАНДАРТ

Steel butt-welded flanges by GOST 12821-80 (types, connecting dimensions and dimensions of sealing surfaces by GOST 12815-80)
Pressure, PN 0,1-0,6; 1,0-6,3; 10; 16; 20 MPa
Diameter nominal DN, mm: 10-1600, 10-1200, 10-400, 15-300, 15-200 
Materials: steel 3сп, 20, 25, 09Г2С, 10Г2, 15Х5М, 12Х18Н10Т

GOST/ГОСТ 12820 Plane Flange/Flat Flange Dimensions PN16 1.6Mpa

Inspection & Quality Control

GOST 12820-80 flanges are supplied with standard quality control, including:

• Dimensional inspection

• Visual examination

• Material verification

• Weld inspection

• Marking and traceability

Certification options:

• Manufacturer Test Certificate

• EN 10204 2.1 / 2.2 / 3.1 (on request)

Applications

• Water supply pipelines

• Heating and district heating systems

• Oil & gas transportation (low pressure)

• Chemical and industrial pipelines

• Power and utility systems

GOST 12820-80 slip on flanges provide a cost-effective and reliable flange solution for low to medium pressure piping systems.
With simple design, wide size availability, and compliance with Russian standards, these steel plate welded flanges are widely used across industrial and infrastructure projects.

Recommended Related Products

• GOST 12821-80 Weld Neck Flanges

• EN 1092-1 Plate Flanges

• ASME B16.5 Slip On Flanges