GOST TYPE 11 flange is a long hub weld neck flange defined in GOST 33259-2015 (replacing GOST 12822-80). It is designed for butt-welding to pipes, with a tapered hub that effectively reduces stress. It is the most widely used type for high-pressure, high-temperature and critical pipelines in oil, gas, petrochemical and power industries. Our GOST TYPE 11 flanges are forged from high-quality materials and precisely machined to ensure safety and stability.
Production Details
Each GOST TYPE 11 flange is manufactured under full-process quality control:
Raw material inspection with mill certificates and spectral analysis
Precision closed-die forging for optimized grain structure
Standardized heat treatment for excellent mechanical properties
High-precision CNC machining for hub, face, RTJ grooves and bolt holes
100% dimensional inspection using CMM and calibrated gauges
Full NDT: magnetic particle testing (MT), ultrasonic testing (UT)
Hydrostatic pressure test to verify safety and integrity
Anti-corrosion oil coating and permanent marking
Full material traceability from raw material to finished product
Product Feature and Application
Key Features
- Fully compliant with GOST 33259-2015 standard dimensions
- Long tapered hub reduces stress concentration and improves fatigue resistance
- Butt-weld structure ensures strong and leak-free connection
- High strength and excellent pressure & temperature resistance
- High precision and full interchangeability
- Suitable for critical and harsh working conditions
Typical Applications
- Oil and gas transmission pipelines
- Petrochemical and refinery process systems
- Power plant boiler and steam pipelines
- High-pressure industrial fluid lines
- Offshore and onshore critical engineering projects
- Russian, CIS and Eastern European high-pressure systems
| Standard | GOST 33259-2015, TYPE 11 |
| Pressure Rating | PN 6, PN 10, PN 16, PN 25, PN 40, PN 63, PN 100 |
| Nominal Diameter | DN 10 – DN 600 |
| Type | Weld Neck Flange (Butt Weld) |
| Face Type | Type B (RF), Type C (RTJ) |
| Materials | Carbon steel St20, 09G2S; Alloy steel 15CrMo; Stainless steel 12Х18Н10Т, 10Х17Н13М2Т |
| Working Temperature | −20 °C – 550 °C |
| Certification | EN 10204 3.1 MTC |
Production Display
Our ISO 9001 certified factory is equipped with large-tonnage forging presses, high-rigidity CNC machining centers, automatic heat treatment lines and professional NDT laboratories. We implement strict process control and complete documentation. Third-party inspection by SGS, BV, TÜV is available upon request.
Product Transport Package
- Surface treatment: Anti-corrosion oil, black paint or varnish
- Packaging: Plastic film, woven bag, export wooden case, steel pallet
- Labeling: Size, pressure, material, standard, heat number, batch
- Documents: Commercial invoice, packing list, certificate of origin, material test certificate
- Transportation: Sea, land and express delivery to global markets
After-sales Service
We provide full life-cycle technical support for GOST TYPE 11 FLANGE:
- Professional consultation on selection, welding and installation
- Custom sizes, materials and drilling per customer drawings
- Timely response to after-sales inquiries and quality claims
- Remote technical guidance and on-site support
- Stable long-term supply for large-scale projects
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