GOST33259-01/12820-80 Plate Flange

Overview

GOST 33259 / GOST 12820-80 Plate Flange is a flat plate–type flange manufactured in accordance with Russian GOST standards, widely used in Russia and CIS countries. It is produced from carbon steel or stainless steel plate by cutting and machining, with precise bolt-hole drilling and sealing face preparation.

This flange type is commonly applied in water supply, district heating, oil & gas auxiliary systems, fire protection, and general industrial piping, especially for low to medium pressure pipelines.

Product Description

GOST Plate Flanges defined under GOST 12820-80 (and harmonized under GOST 33259) are flat plate flanges without a hub, designed for direct welding to the pipe or for use as backing flanges.

GOST 33259 is the newer unified standard that consolidates and updates earlier GOST flange standards, while GOST 12820-80 remains widely referenced in drawings and technical documents.

Key Features & Functions

• Key Features

• GOST standard compliance
  Fully compatible with Russian and CIS pipeline systems following GOST standards.

• Economical plate-type design
  Plate manufacturing provides a cost-effective alternative to forged or neck flanges.

• Wide pressure rating coverage
  Suitable for PN6 to PN40 applications depending on system requirements.

• Reliable sealing performance
  Machined sealing surface ensures proper gasket seating and leak-tight joints.

• Broad application scope
  Widely used in municipal, industrial, and utility pipeline networks.

• Main Functions

• Provides a bolted flange connection for pipes, valves, and fittings

• Ensures pressure containment and sealing integrity

• Allows easy installation and maintenance of pipeline systems

Applications

GOST ATK 24.200.02-90 Blind Flanges are widely used in:

• Oil & gas pipelines

• Petrochemical and chemical plants

• Power generation facilities

• Water supply and district heating systems

• Industrial piping systems

• Fire protection and utility pipelines

Installation Process

1. Inspection

• Verify flange size, PN rating, material, and sealing surface.

• Ensure the flange face is clean and undamaged.

2. Gasket Installation

• Select a suitable gasket (rubber, graphite, spiral wound, or metal gasket).

• Ensure proper centering between flanges.

3. Bolt Alignment

• Align bolt holes of the blind flange with the mating flange.

4. Bolt Tightening

• Tighten bolts gradually using a cross (diagonal) pattern.

• Apply uniform torque to prevent leakage.

5. Pressure Testing (If Required)

• Recheck bolt tightness before pressure testing the system.

  
  

Flange production process

Factory Showcase

FAQ

Q1: What is the relationship between GOST 33259 and GOST 12820-80?

GOST 33259 is the updated standard that unifies several older GOST flange standards, including GOST 12820-80.
In practice, many projects still specify GOST 12820-80, but production is often carried out according to GOST 33259 dimensions.

Q2: Is GOST Plate Flange equivalent to EN 1092-1 Type 01?

Functionally, both are plate flanges without a hub, but dimensions, drilling patterns, and pressure ratings are not interchangeable.
Always follow the specified standard to avoid mismatch.

Q3: What pressure ratings are most commonly used?

• PN10 / PN16 – water supply, district heating, fire protection

• PN25 / PN40 – industrial and higher-pressure systems

Q4: What materials are typically supplied?

• Carbon steel (commonly used for water and heating systems)

• Stainless steel (for corrosion-resistant or special applications)
  Material grade should follow project specifications.

Q5: What facing types are available?

Depending on the GOST requirement:

• Flat Face (FF)

• Raised Face (RF)

Gasket type and system design should be considered when selecting the facing.

Q6: What industries commonly use GOST 12820-80 plate flanges?

• Municipal water and heating networks

• Fire protection systems

• Oil & gas auxiliary pipelines

• General industrial utilities