GOST Flanges Suppliers

GOST flanges are designed according to specific pressure classes and dimensional norms set by Russian engineering standards. The most common pressure ratings include:

1. PN6, PN10, PN16, PN25, PN40, PN63, PN100, and PN160

Each rating corresponds to a maximum working pressure in bar. These flanges are available in a wide range of diameters, generally from:

1. DN10 to DN2000, accommodating both low-pressure and high-pressure industrial systems.

Typical dimensions specified include:

1. Flange outer diameter (OD)
2. Bolt circle diameter (BCD)
3. Number and size of bolt holes
4. Flange thickness (C)
5. Raised face or sealing surface details (type B, C, D, etc.)

These dimensions are crucial to ensure proper sealing, mechanical integrity, and compatibility in pressure pipeline applications. Manufacturers exporting to Eastern Europe, Russia, Kazakhstan, and CIS countries rely on accurate GOST-compliant flanges to meet regional infrastructure standards.

PN (Pressure Nominale) ratings in GOST flanges represent the maximum allowable pressure (in bars) at a reference temperature. These are crucial when selecting flanges for pipelines in industries like oil & gas, chemical processing, and waterworks.

Here’s how PN ratings typically align and compare with ANSI pressure classes:

• PN 6 ≈ Class 150
• PN 10 ≈ Class 150
• PN 16 ≈ Class 150–300
• PN 25 ≈ Class 300
• PN 40 ≈ Class 600
• PN 63, 100, 160 = Higher pressure systems (no direct ANSI equivalent; used in specialized pipelines)

Key Points to Understand:

• PN ratings are metric-based, while ANSI uses psi-based pressure classes.
• GOST flanges are often chosen for systems designed under Russian, CIS, and Eastern European norms.
• Compatibility between GOST and ANSI systems requires special attention to drilling patterns, face types, and bolt holes.

This comparison helps global buyers understand the pressure compatibility when sourcing GOST flanges from manufacturers like us.

GOST standards define a comprehensive range of industrial flange types, each designed for specific applications, pressure classes, and connection methods. Below are the most recognized GOST flange types used across process industries:

1. GOST 12820-80 – Flat Welding Flanges (Type 01):

   Designed for butt welding with pipe, suitable for lower-pressure pipelines and systems requiring easy installation.

2. GOST 12821-80 – Weld Neck Flanges (Type 11):

   Ideal for high-pressure and high-temperature environments, offering superior strength due to the long tapered hub.

3. GOST 12822-80 – Blind Flanges (Type 05):

   Used to close off the ends of piping systems and pressure vessels, commonly applied in maintenance and testing.

4. GOST 12815-80 – Flange Connection Standards:

   Governs bolt-hole arrangements, sealing faces (raised, flat, tongue & groove), and flange matching guidelines.

5. GOST 12836-67 – Threaded Flanges (Type 13):

   Suitable for systems where welding is not feasible, often used in smaller diameter, low-pressure applications.

6. GOST 12823-67 – Loose Flanges with Welded Ring (Type 21):

   Allows for rotational alignment of bolt holes, commonly used where frequent dismantling is required.

7. GOST 28759.3-90 – Integral and Custom Machined Flanges:

   Special-purpose flanges produced as part of a forged or machined fitting, often for critical or bespoke systems.

Each type is engineered to meet specific industrial conditions as per Russian engineering standards, ensuring compatibility, pressure integrity, and durability in complex piping environments.

The surface finish of a flange plays a critical role in ensuring the effectiveness and longevity of the gasket seal. In GOST flange manufacturing, surface roughness is tightly controlled as per the sealing face type selected, such as flat face (FF), raised face (RF), or tongue & groove (T&G). Here’s how it impacts performance:

• Rougher finishes (e.g., spiral serrated 3.2 to 6.3 µm Ra):

  These are preferred for soft gaskets like graphite or PTFE, as they allow the gasket to embed into the serrations, creating better sealing under lower bolt loads.

• Smoother finishes (e.g., Less Than 1.6 µm Ra):

  Suitable for metallic gaskets such as ring-type joints or jacketed gaskets, where a tighter metal-to-metal seal is required.

• GOST Sealing Face Standards:

  The standards define precise machining tolerances to ensure uniformity, minimize leakage risk, and improve gasket lifespan under pressure or thermal cycling.

• Impact on Leak Prevention:

  A properly selected and machined surface finish minimizes micro-paths for fluid escape, especially in critical services like steam, gas, or corrosive fluids.

Correct gasket compatibility and surface finish selection in accordance with GOST specifications is essential for achieving a leak-proof, maintenance-free pipeline system.

Yes, we export high-quality GOST standard flanges globally, catering to various industries that require Russian and CIS-compliant flange connections. Our manufacturing and export processes strictly adhere to GOST specifications and international shipping norms.

Primary Export Destinations:

• Russia and CIS Countries: Kazakhstan, Belarus, Uzbekistan, Armenia, Azerbaijan
• Middle East: UAE, Saudi Arabia, Qatar, Oman, Iraq
• Europe: Poland, Bulgaria, Romania, Serbia, Ukraine
• Asia & Africa: Vietnam, Indonesia, Egypt, South Africa

Why Global Clients Choose Us for GOST Flanges:

• Strict compliance with GOST flange specifications including GOST 12815, GOST 12820, GOST 12821, and others
• Availability in pressure ratings from PN6 to PN250 and sizes from DN10 to DN2000
• Durable surface coatings like zinc, anti-corrosion black paint, or hot-dip galvanizing
• Custom documentation for international projects including Certificate of Origin, Test Reports, and Inspection Certificates
• On-time delivery and custom packaging suitable for marine or air shipments

Our capability to manufacture and export GOST flanges with precise tolerances and fast lead times makes us a preferred supplier for both EPC contractors and government utility projects.