： +8618979570760 ：xuran1603@gmail.com WhatsApp：+8619170756831
English
 |
| Quantity: | |
|---|---|
SO Flange
SDFL
The EN 1092-1 Type 05B DN300 weld neck flange is a forged pipe fitting designed for medium to high pressure piping systems, manufactured in full compliance with EN 1092-1 European standard. It features an integral tapered neck that transitions from the flange body to the pipe wall thickness, enabling full penetration butt welding between the flange and pipe. This design distributes stress at the joint evenly, reduces stress concentration at the weld seam, and improves long-term structural stability under pressure cycling and thermal expansion conditions. The flange is produced under an ISO 9001 certified quality management system, with all production processes traceable from raw material incoming inspection to final shipment testing.
Standard production uses ASTM A182 F304 and F304L austenitic stainless steel. Optional grades include F316, F316L, F51 (SAF 2205 duplex stainless steel), F53 (2507 super duplex stainless steel) and ASTM B625 nickel-based alloy, as well as 2520 heat-resistant stainless steel. Each material grade corresponds to specific corrosion resistance, temperature tolerance and mechanical property profiles to adapt to different industrial operating environments. All raw materials are sourced from certified steel mills with material mill certificates provided for each batch.
This DN300 Type 05B weld neck flange covers pressure ratings from PN10 to PN100, with corresponding flange thickness, hub height and bolt specifications adjusted according to pressure grade. Higher pressure classes feature thicker flange bodies and higher hubs to ensure structural integrity under rated operating pressure. All pressure ratings follow the dimensional tolerances specified in EN 1092-1 standard to ensure interchangeability with standard piping components.
Dimensional Item | Value |
|---|---|
Flange outer diameter | 445 |
Bolt circle diameter | 400 |
Seal face outer diameter | 370 |
Raised face diameter | 350 |
Bore diameter | 327.5 |
Flange body thickness | 26 |
Hub height | 46 |
Bolt hole specification | 12-22 |
Hub transition radius | R12 |
The integral weld neck structure transfers piping stress to the flange body through the tapered neck, avoiding concentrated stress at the flange plate edge. Compared with slip-on flanges, weld neck flanges can withstand higher operating pressure and more frequent pressure fluctuations. The full penetration butt weld joint provides consistent pipe wall continuity, which reduces flow turbulence and improves fatigue resistance under cyclic loading.
The Type 05B flange adopts raised face (RF) sealing surface, machined to EN standard surface finish requirements. When compressed with matching gaskets, it forms a uniform and stable seal suitable for liquid, gas and steam media. The butt weld connection creates a permanent and rigid joint, with minimal risk of joint displacement or leakage under thermal expansion, vibration or pressure shock conditions.
Weld neck flanges are widely used in petrochemical utility and auxiliary systems, including process water networks, drainage systems and medium-pressure vent lines. In water treatment plants, they are applied to filter pipe connections, chemical dosing lines and medium to high pressure pump connections. They are also commonly installed in commercial building HVAC chilled and hot water piping systems, as well as industrial process piping with stable medium to high pressure operating conditions.
All flanges undergo multi-stage quality control throughout production. Raw materials are verified via PMI spectral analysis to confirm material composition. Forging and heat treatment processes are monitored to ensure proper grain structure and mechanical properties. Final CNC machining is inspected for dimensional accuracy, and finished products pass hydrostatic pressure testing and visual surface inspection before packaging. All inspection records are filed and available for customer review.
Customization services include non-standard bore sizes, custom hub lengths, special sealing face types and material grade adjustments. Laser marking of part numbers, project codes or customer logos is available on request. Standard sizes are produced with regular stock to support fast delivery for urgent orders. Bulk production lead times are confirmed at order placement, with production scheduling updated regularly to keep customers informed of progress. Export packaging options include fumigated wooden crates and pallets to meet international shipping requirements.
A weld neck flange uses full penetration butt welding with an integral tapered neck, suitable for medium to high pressure and cyclic loading conditions. A slip-on flange uses fillet welding with a short hub, designed primarily for low to medium pressure stable operating conditions, with lower installation cost and alignment requirements.
Yes, all dimensions, bolt hole positions and sealing face specifications are produced in accordance with EN 1092-1 Type 05B standard, ensuring interchangeability with other EN standard piping components of the same pressure rating.
Yes, this Type 05B weld neck flange is available in a full range of DN sizes and PN pressure classes from PN10 to PN100. Customers may provide specific size and pressure requirements for quotation and production arrangement.
Each shipment includes original material mill certificates from the steel mill, as well as factory inspection reports covering dimensional verification and pressure testing. Third-party inspection certificates can be provided upon customer request.
