C&N industrial Group, pipe, fitting and flanges manufacturers,fbe epoxy and pe coating for pipeline since 1991,with brand C&N huitong ,C&N hongcheng.
The A694 F65 B16.5 WN RTJ flange is a high-strength carbon steel forged flange specifically designed for high-temperature and high-pressure transmission applications. The A694 F65 material offers extremely high yield strength and excellent weldability, enabling it to withstand the high stresses generated during high-pressure transmission, making it an ideal choice for large-diameter high-pressure pipelines. Compared with traditional carbon steel flanges, the A694 F65 flange has approximately twice the yield strength of conventional A105 flanges, allowing for a lighter and more compact design under the same pressure rating. This provides significant advantages for engineering scenarios that are highly sensitive to weight, such as offshore platforms and deep-water facilities.
This weld neck flange adopts integral die forging as the core production process, which completely eliminates internal porosity, shrinkage and other defects that often appear in cast products. The elongated welding neck creates a smooth transition between the flange body and connected pipes, which effectively disperses dynamic stress caused by fluid flow, pipeline vibration and temperature fluctuation. This structural design greatly improves the overall fatigue resistance and service life of the entire piping system, especially for long-term running high-pressure pipeline networks in complex working environments.
Chemical composition requirements of A694 F65 Flanges
| Element | Requirement (wt. %) |
| Carbon (C) | ≤ 0.30 |
| Manganese (Mn) | ≤ 1.60 |
| Phosphorus (P) | ≤ 0.030 |
| Sulfur (S) | ≤ 0.030 |
| Silicon (Si) | ≤ 0.35 |
| Ni, Cr, Mo | As required |
To ensure the weldability, crack resistance and low-temperature toughness of the material, ASTM A694 precisely limits the content of each element.The carbon equivalent of A694 F65 shall not exceed 0.42%. This control of carbon equivalent is critical for ensuring the flange’s crack resistance during welded connections, especially in the weld area where the welding neck joins the pipe.
ASTM A694 F65 Flanges Mechanical Properties
Thanks to the high-strength characteristics of the F65 material, the A694 F65 flange offers excellent forgeability and machinability. Compared with a same-size flange made of A105 material, the A694 F65 flange achieves significantly lower overall weight while maintaining or even improving connection reliability.
| Property | Requirement |
| Yield Strength | ≥ 65 ksi (450 MPa) |
| Tensile Strength | 77–95 ksi (530–655 MPa) |
| Elongation | ≥ 20 % |
Manufacturing Process and Heat Treatment Specifications
All ASTM A694 flanges must be produced by fully deoxidized melting processes (open hearth, electric furnace or basic oxygen converter), and direct machining from plate or solid bar stock is prohibited. The hot forging process must be performed to form a uniform wrought structure throughout the flange, eliminate casting defects, and ensure the compactness and consistency of mechanical properties of the material.
All finished flanges undergo standardized heat treatment after forging to refine internal grain structure and remove residual forging stress. The optimized metallographic structure keeps mechanical performance stable even under repeated alternating loads of high temperature and high pressure, avoiding strength reduction or permanent deformation during long-term field operation.
Dimensional Standards and Application Specifications
The dimensions of ASTM A694 flanges can follow the following international standards:
- MSS SP44 (Steel Pipeline Flanges Standard)
- ASME B16.5 (Pipe Flanges and Flanged Fittings Standard)
- ASME B16.47 (Large Diameter Steel Flanges Standard)
Application Specifications
This series of flanges comply with the following pipeline system design standards:
- ASME B31.3 Process Piping
- ASME B31.4 Pipeline Transportation Systems for Liquids and Slurries
- ASME B31.8 Gas Transmission and Distribution Piping Systems
Typical Application Fields
ASTM A694 F52/F60/F65 flanges are mainly used in the following fields due to their excellent high-pressure bearing capacity and reliable long-term performance:
- Oil and Gas Exploitation: End connections of valves and equipment in wellhead devices, Christmas tree manifolds and subsea production systems
- Long-distance Transmission: Onshore and offshore high-pressure oil and gas long-distance transmission pipelines, natural gas transmission and distribution networks
- Petrochemical Industry: Connection of high-pressure process pipelines, heat exchangers, reaction vessels and other equipment
- Energy and Power: High-pressure water supply systems, steam pipelines and auxiliary equipment
How to order our ASTM A694 F65 Flanges?
Example
WELDING, NECK FLANGE, A694 – F65, RTJ -WN, Sch 80,ANSI B16.5, 900#,16in,
WELD NECK FLANGE, A694 – F65, RTJ -WN, Sch 40,ANSI B16.5, 1500#,8in
We can also apply HIC testing (Hydrogen-Induced Cracking) for the A694 F65 Materials.
As a professional high-quality flange manufacturer, C&N ensures that every A694 F65 B16.5 WN RTJ flange is produced under strict quality control. Our advanced forging and heat treatment equipment enables us to achieve precise dimensional tolerances and consistent mechanical properties, ensuring stable production quality. C&N offers A694 F65 flanges in various specifications. If you have any needs, please contact us today.
