Flange CS – Complete Guide to Carbon Steel Flanges
Introduction
A Flange CS refers to a Carbon Steel flange — one of the most widely used components in industrial piping systems. These flanges connect pipes, valves, pumps, and other equipment, creating a secure, leak-proof seal that can handle high pressures and temperatures.
At Fortis Forge, we specialize in manufacturing high-quality carbon steel flanges that meet international standards like ASME, ANSI, DIN, EN, and JIS. Whether you’re working in oil & gas, power generation, chemical processing, or water treatment, the right flange makes all the difference in performance and safety.
1. What is a Flange CS?
A CS flange is a forged or cast steel ring designed to connect sections of pipe or attach pipe to a pressure vessel, valve, or other components. It is bolted together with a matching flange and sealed with a gasket to prevent leaks.
Why carbon steel?
Strength and durability
Cost-effectiveness
High pressure and temperature resistance
Compatibility with a wide range of media
2. Types of Carbon Steel Flanges (Flange CS)
2.1 Weld Neck Flange
Long tapered hub for high-stress applications
Ideal for high pressure & temperature
2.2 Slip-On Flange
Slides over the pipe before welding
Economical, easy to align, but slightly weaker than weld neck
2.3 Socket Weld Flange
Used for smaller, high-pressure pipes
Welded on the socket end for strong connections
2.4 Blind Flange
Closes the end of a pipeline
Allows easy inspection and reopening of lines
2.5 Threaded Flange
Screwed onto pipes without welding
Best for low-pressure applications
2.6 Lap Joint Flange
Works with a stub end for systems needing frequent dismantling
2.7 Orifice Flange
Used for flow measurement with orifice plates
3. Material Grades for Flange CS
Fortis Forge offers CS flanges in various grades, such as:
ASTM A105 – Forged carbon steel
ASTM A350 LF2 – Low-temperature carbon steel
ASTM A694 – High-yield strength carbon steel for high-pressure transmission
4. Standards & Dimensions
We manufacture Flange CS according to:
ASME/ANSI B16.5 – For sizes up to 24″
ASME B16.47 Series A & B – For sizes above 24″
DIN EN 1092-1 – European standard
JIS B2220 – Japanese standard
Pressure Classes: 150, 300, 600, 900, 1500, and 2500 lbs
5. Manufacturing Process at Fortis Forge
Material Selection – High-grade carbon steel billets
Forging – Shaping under high pressure for strength
Heat Treatment – Enhances mechanical properties
Machining – Achieving precise dimensions and smooth surfaces
Drilling – Bolt holes according to flange standard
Inspection & Testing – Hydrostatic, ultrasonic, and dimensional checks
6. Advantages of Using Carbon Steel Flanges
High Strength – Withstands high pressure and temperature
Cost-Effective – More affordable than stainless steel
Versatile – Suitable for water, oil, gas, and steam systems
Customizable – Can be made to specific dimensions and coatings
7. Common Applications of Flange CS
Oil & Gas pipelines
Petrochemical plants
Power generation plants
Water treatment facilities
Shipbuilding & marine systems
Fire protection systems
8. Protective Coatings for Flange CS
To enhance durability, CS flanges can be coated with:
Galvanization – Zinc coating for corrosion resistance
Epoxy Coating – Protection against chemicals
Black Oxide – Rust prevention in dry environments
9. Installation Tips for Carbon Steel Flanges
Check Surface Flatness – Prevent gasket leaks
Use Correct Gasket Material – Match media and temperature
Tighten Bolts Evenly – Use cross-pattern tightening
Inspect Before Service – Check for cracks, rust, or misalignment
10. Maintenance & Service Life
Regular Inspection – Spot corrosion and wear early
Bolt Re-Tightening – Prevent loosening due to vibration
Surface Cleaning – Remove debris and chemical deposits
Gasket Replacement – Extend operational life
11. Why Choose Fortis Forge for Flange CS?
Certified Quality – ASME, DIN, JIS, ISO approved
Wide Range – All flange types & sizes in stock
Custom Manufacturing – Non-standard dimensions available
Global Supply Network – Fast delivery worldwide
Competitive Pricing – Premium quality at market rates
12. Frequently Asked Questions
Q1: What is the maximum pressure a CS flange can handle?
Depends on class — Class 2500 flanges can handle over 6000 PSI at lower temperatures.
Q2: Are CS flanges suitable for seawater applications?
With proper coating, yes, but stainless steel is preferred for prolonged exposure.
Q3: Can CS flanges be reused?
Yes, if undamaged and threads/bolt holes remain intact.
Q4: What’s the difference between forged and cast CS flanges?
Forged flanges have better strength and toughness compared to cast ones.
Q5: Do Fortis Forge flanges come with mill test certificates?
Yes — every product is supplied with full documentation.
Conclusion
A Flange CS is more than a simple connector — it’s a vital part of any industrial piping system. With high strength, versatility, and cost efficiency, carbon steel flanges remain the first choice for engineers and contractors worldwide.
At Fortis Forge, we deliver flanges that combine superior material quality, precise engineering, and strict adherence to international standards — ensuring your piping systems perform safely and efficiently for years to come.