Overview
Carbon steel flanges provide superior strength and durability compared to mild steel alternatives, making them the preferred choice for high-pressure and high-temperature applications. Our range includes weld neck, slip-on, blind, threaded, and socket weld flanges — manufactured to ASME B16.5 standards with material grades including ASTM A105 and ASTM A694.
Features
- Superior strength for high-pressure applications
- Excellent high-temperature performance
- Multiple types: Weld Neck, Slip-On, Blind, Threaded, Socket Weld
- Materials: ASTM A105, ASTM A694
- Precision machined for leak-proof connections
- Available with various facing finishes
Specifications
| Material Grades | ASTM A105, ASTM A694 |
| Standards | ASME B16.5, ASME B16.47 |
| Size Range | ½ inch to 48 inches |
| Pressure Classes | Class 150 to Class 2500 |
| Types | Weld Neck, Slip-On, Blind, Threaded, Socket Weld |
| facing | Flat Face, Raised Face, Ring Joint |
Applications
Oil & Gas
High-pressure pipelines and processing equipment
Chemical Processing
High-temperature chemical lines and reactors
Power Generation
Steam lines, boiler connections, and turbine piping
Petrochemical
Refinery piping and pressure vessel connections
FAQ
Carbon steel flanges contain a higher carbon content typically 0.30 percent or more compared to mild steel at 0.05 to 0.25 percent which gives them greater tensile strength, hardness, and pressure-holding capability. CS flanges manufactured to ASTM A105 can handle working pressures up to Class 2500 and temperatures up to 1,000 degrees Fahrenheit, making them suitable for high-pressure steam systems, oil and gas transmission lines, and chemical reactor connections. Mild steel flanges to ASTM A53 have lower strength ratings, typically limited to Class 150 and Class 300 service at moderate temperatures. However, MS flanges are more economical, generally costing 20 to 30 percent less than equivalent CS flanges, and offer superior weldability and formability. The choice depends primarily on the operating pressure, temperature, and fluid being handled.
Carbon steel flanges are available across a wide pressure range from Class 150 suitable for working pressures up to 285 PSI at ambient temperature, through Class 300, 600, 900, 1500, and up to Class 2500 which can handle pressures exceeding 6,000 PSI depending on the temperature derating factors. The specific pressure class required depends on the operating temperature, as flange pressure ratings decrease at elevated temperatures per ASME B16.5 tables. For example, a Class 150 flange rated at 285 PSI at 100 degrees Fahrenheit derates to approximately 185 PSI at 500 degrees Fahrenheit. Higher pressure classes use thicker flanges with larger bolt circles and heavier bolting to maintain joint integrity. We help select the appropriate material grade such as ASTM A105 for standard service or A694 for higher yield requirements to match your pressure and temperature conditions.