Carbon Steel Threaded Flange – Complete Guide by Fortis Forge
Introduction
When welding is not an option, carbon steel threaded flanges provide a reliable, secure, and efficient method of connecting pipes, valves, pumps, and other equipment. These flanges are designed with internal threads that match the external threads on a pipe, allowing quick assembly without welding.
At Fortis Forge, we specialize in producing carbon steel threaded flanges in compliance with ASTM, ASME, ANSI, DIN, and EN standards. Our products are widely used in industries such as oil & gas, chemical processing, water treatment, and fire protection systems, where strong, corrosion-resistant, and cost-effective solutions are required.
1. What Is a Carbon Steel Threaded Flange?
A threaded flange (also called a screwed flange) is a type of flange with female threads machined into the bore. It connects to a male-threaded pipe, eliminating the need for welding.
Key Features:
Internal Threads – Match the pipe’s external threads for a secure fit.
Weld-Free Connection – Ideal for environments where welding is dangerous or impractical.
Reusability – Can be removed and reused, unlike welded joints.
2. Advantages of Carbon Steel Threaded Flanges
No Welding Required – Perfect for flammable, explosive, or hazardous environments.
Easy Installation & Removal – Reduces downtime during maintenance.
Strong Mechanical Properties – Carbon steel ensures durability and pressure resistance.
Cost-Effective – Eliminates welding labor costs.
Reusability – Can be dismantled without damaging the flange or pipe.
3. Why Carbon Steel Is Ideal for Threaded Flanges
High Strength – Handles high-pressure systems effectively.
Temperature Resistance – Performs in both extreme cold and heat.
Corrosion Resistance – When coated or galvanized, it withstands aggressive environments.
Affordable – Cheaper than stainless steel, yet offers comparable performance in many cases.
4. Types of Carbon Steel Threaded Flanges
At Fortis Forge, we manufacture:
Raised Face (RF) Threaded Flanges – For better sealing with gaskets.
Flat Face (FF) Threaded Flanges – For connections to cast iron or fiberglass flanges.
Ring Type Joint (RTJ) Threaded Flanges – For high-pressure, leak-proof sealing.
Threaded Reducing Flanges – Connect pipes of different diameters.
5. Standards & Specifications at Fortis Forge
We manufacture threaded flanges in compliance with:
ASTM A105 / A350 LF2 / A694 F42-F70
ASME B16.5
DIN, JIS, EN
Pressure Classes: 150, 300, 600, 900, 1500 lbs
Sizes: ½” to 24”
6. Manufacturing Process
Raw Material Selection – Certified carbon steel billets.
Forging – Enhances grain structure and strength.
Heat Treatment – For optimal hardness and toughness.
Machining – CNC precision for accurate thread profiles.
Surface Finishing – Anti-corrosion coating, galvanizing, or painting.
Quality Inspection – Dimensional, mechanical, and visual checks.
7. Applications of Carbon Steel Threaded Flanges
Oil & Gas Pipelines – Especially where welding may cause sparks.
Chemical Processing Plants – For handling flammable or toxic fluids.
Water Supply Systems – Municipal and industrial.
Fire Protection Systems – Quick installation in sprinkler networks.
Marine & Offshore Platforms – Resistant to corrosion when coated.
8. How Threaded Flanges Work in a Piping System
The male-threaded pipe is aligned with the female threads in the flange.
The pipe is screwed in until it fits tightly, ensuring leak resistance.
A gasket may be used between flange faces for better sealing.
The flange is bolted to its mating flange to complete the connection.
9. Benefits in Installation & Maintenance
Safe for Hazardous Locations – No heat or sparks from welding.
Quick Assembly – Ideal for field installations.
Minimal Downtime – Easy to replace without cutting pipes.
Portable & Reusable – Useful for temporary systems.
10. Quality Control & Testing at Fortis Forge
We ensure every flange meets the highest standards through:
Hydrostatic Testing – To confirm leak-tight performance.
Ultrasonic Testing – Detecting internal flaws.
Dimensional Inspection – Ensuring perfect fit and alignment.
Mechanical Testing – Verifying yield, tensile, and hardness properties.
Material Certification – Mill Test Certificates (EN 10204 3.1 / 3.2).
11. Why Choose Fortis Forge for Threaded Flanges?
Global Export Capability – Serving clients worldwide.
Custom Solutions – Non-standard sizes and designs available.
Ready Stock – For urgent deliveries.
Competitive Pricing – Premium quality without premium cost.
12. Maintenance Tips
Use thread sealant or PTFE tape to prevent leaks.
Avoid over-tightening to prevent thread damage.
Inspect threads regularly for wear or corrosion.
Keep threads clean and lubricated for easy disassembly.
13. FAQs
Q: Can threaded flanges be used for high-pressure steam?
A: Generally, they are best for moderate pressures; for very high pressures, welding is recommended.
Q: What’s the main advantage over socket weld flanges?
A: Threaded flanges require no welding, making them safer for hazardous environments.
Q: Can they be used for corrosive fluids?
A: Yes, when made from corrosion-resistant carbon steel grades or coated appropriately.
Conclusion
Carbon steel threaded flanges offer a safe, efficient, and cost-effective solution for connecting pipes in environments where welding is not possible or practical. Their reusability, ease of installation, and strong mechanical properties make them ideal for various industries.
At Fortis Forge, our threaded flanges are manufactured to exacting standards, undergo rigorous testing, and are available in both standard and custom configurations. Whether your project is in oil & gas, water treatment, or marine applications, we deliver flanges that perform — on time, every time.