Carbon Steel Flange Product Overview
Carbon steel flanges connect pipes, valves, pumps, and equipment in pressure piping systems. Huaxia-Steel supplies forged carbon steel flanges in weld neck, slip-on, blind, socket weld, threaded, and lap joint types according to ANSI B16.5, ANSI B16.47, EN 1092-1, JIS B2220, and GOST standards. All flanges are forged from bar or billet, CNC machined, and supplied with material certificates.
Standard Sizes and Pressure Ratings
| Parameter | Range |
|---|---|
| Nominal size | 1/2 inch – 48 inch (DN15 – DN1200) |
| Pressure class | 150# – 2500# (ANSI); PN6 – PN400 (EN) |
| Wall thickness | Sch 10 – Sch XXS, per ASME B36.10M |
| Facing | Raised face (RF), flat face (FF), ring-type joint (RTJ) |
| Coating | Black paint, rust-preventive oil, galvanized on request |
Available Materials and Grades
| Grade | Standard | Typical Service |
|---|---|---|
| A105 | ASTM A105 | General pressure piping, 150#–2500# |
| A105N | ASTM A105N | Normalized, improved toughness |
| A350 LF2 | ASTM A350 | Low-temperature service |
| Q235B | GB/T 700 | Water, air, low-pressure systems |
| 20# steel | GB/T 699 | Chinese pressure piping |
Manufacturing Process and Standards
Our flanges are produced through a controlled forging and machining process:
- Forging: billets are heated and forged to approximate shape, refining grain structure.
- Heat treatment: normalized or quenched-and-tempered as required by grade and specification.
- CNC machining: facing, boring, bolt-hole drilling, and groove machining to exact dimensions.
- Visual and dimensional inspection: each flange is checked for surface defects and measured against the standard.
- Marking and certification: heat number, size, rating, and standard are stamped or engraved.
Applicable standards include ANSI/ASME B16.5, B16.47 Series A/B, EN 1092-1, JIS B2220, GOST 12820/12821, and API 6A for high-pressure applications.
Applications
- Oil and gas pipelines and process piping
- Petrochemical and refinery plants
- Power generation and boiler systems
- Water treatment and desalination plants
- Shipbuilding and marine engineering
- General industrial piping and HVAC systems
Quality Assurance
We supply material certificates per EN 10204 3.1, including chemical composition, mechanical properties, heat treatment records, and dimensional reports. Additional testing available:
- Hydrostatic testing
- PMI spectrometry
- Hardness testing
- Ultrasonic testing of forgings
- Third-party inspection by SGS, BV, TUV, or Lloyd’s
Packaging and Shipping
Flanges are packed in seaworthy wooden crates or pallets, separated by cardboard or foam to protect sealing faces. Bolt holes are covered with plastic caps, and surfaces are oiled or painted for corrosion protection. Each package is labeled with size, rating, standard, heat number, and quantity.
Request a Quotation
Tell us the type, size, pressure class, facing, material grade, standard, and quantity. Huaxia-Steel will provide a factory-direct quotation with lead time and shipping options. Contact us today.
