API 6A Type 6B 5000 psi(34.5 MPa) Weld Neck RTJ Flange,API 6A 6B Weld Neck Flange,API Weld neck Flange
C&N is a professional manufacturer of API 6A Type 6B 5000 psi(34.5 MPa) Weld Neck RTJ Flange,API 6BX Weld neck Flange,API weld neck flange
What Is API 6A Type 6B Weld Neck RTJ Flange?
The API 6A Type 6B Weld Neck RTJ Flange is a high-pressure flange designed for oilfield wellhead and Christmas tree equipment. Manufactured according to API 6A standards, these flanges are commonly used in drilling, production, and oil and gas transmission systems.
API 6A Type 6B flanges feature a weld neck hub design that provides excellent reinforcement and stress distribution in high-pressure applications. The RTJ (Ring Type Joint) sealing surface ensures reliable sealing performance under extreme pressure and temperature conditions.
With a pressure rating of 5000 psi (34.5 MPa), these flanges are widely used in wellhead assemblies, pipeline manifolds, and pressure control systems.
API 6A 6B Weld Neck Flange Specifications
| Item | Specification |
|---|---|
| Standard | API 6A |
| Flange Type | Weld Neck RTJ |
| Type | 6B |
| Pressure Rating | 5000 PSI (34.5 MPa) |
| Size Range | 2-1/16″ – 11″ |
| Sealing Surface | RTJ (Ring Type Joint) |
| Application | Wellhead / Oilfield Equipment |
All tolerances and ring gasket dimensions comply with API 6A specifications.
Materials for API 6A Type 6B Weld Neck RTJ Flange
API 6A weld neck flanges are manufactured from various materials depending on operating conditions.
Carbon Steel
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ASTM A105 / A105N
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ASTM A350 LF2
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ASTM A694 F42 / F46 / F52 / F60 / F65 / F70
Alloy Steel
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AISI 4130
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AISI 4140
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AISI 4340
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AISI 8630
Stainless Steel
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ASTM A182 F304 / F304L
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ASTM A182 F316 / F316L
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ASTM A182 F321 / F347
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ASTM A182 F904L
Duplex Stainless Steel
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ASTM A182 F51 / UNS S31803
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ASTM A182 F53 / UNS S32750
Nickel Alloys
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Inconel 600 / 625
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Incoloy 800 / 825
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Hastelloy C276 / C22
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Monel 400 / K500
Cladding Materials
For corrosive environments, API 6A weld neck flanges can be supplied with corrosion-resistant cladding materials such as:
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Stainless Steel 304 / 316
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Duplex Stainless Steel 2205 / 2507
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Inconel 625
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Hastelloy C276
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Monel 400
API 6A Type 6B 5000 psi(34.5 MPa) Weld Neck RTJ Flange Dimensions and Drawing
| SIZE | FLANGE DIAM. | RTJ DIM. | FLANGE HEIGHT | BOLTING | FLANGE HUB | RING | ||||||||
| NPS | OD | C | K | P | T | Q | LN | BC | N | H | X | HL | JL | R / RX |
| 2-1/16″ | 215 | 3 | 124 | 95.25 | 46.1 | 38.1 | 109.5 | 165.10 | 8 | 26 | 104.8 | 60.3 | 43.7 | 24 |
| 2-9/16″ | 245 | 3 | 137 | 107.95 | 49.3 | 41.3 | 112.7 | 190.50 | 8 | 29 | 123.8 | 73.0 | 54.9 | 27 |
| 3-1/8″ | 265 | 3 | 168 | 136.53 | 55.6 | 47.7 | 125.4 | 203.20 | 8 | 32 | 133.3 | 88.9 | 67.5 | 35 |
| 4-1/16″ | 310 | 3 | 194 | 161.93 | 62.0 | 54.0 | 131.8 | 241.30 | 8 | 35 | 161.9 | 114.3 | 88.1 | 39 |
| 5-1/8″ | 375 | 3 | 229 | 193.68 | 81.0 | 73.1 | 163.5 | 292.10 | 8 | 42 | 196.8 | 141.3 | 110.3 | 44 |
| 7-1/16″ | 395 | 6 | 248 | 211.15 | 92.1 | 82.6 | 181.0 | 317.50 | 12 | 39 | 228.6 | 168.3 | 132.6 | 46 |
| 9″ | 485 | 6 | 318 | 269.88 | 103.2 | 92.1 | 223.8 | 393.70 | 12 | 45 | 292.1 | 219.1 | 173.8 | 50 |
| 11″ | 585 | 6 | 371 | 323.85 | 119.1 | 108.0 | 265.1 | 482.60 | 12 | 51 | 368.3 | 273.1 | 216.7 | 54 |
*All dimensions are in mm unless otherwise specified.
*Tolerances and ring gaskets are according to API 6A.
API 6A vs ASME Flanges
Although API 6A flanges and ASME B16.5 flanges may share similar dimensions, their pressure ratings and applications are different.
| Standard | Typical Pressure | Application |
|---|---|---|
| ASME B16.5 | Up to Class 1500 | Industrial piping |
| API 6A | Up to 20000 PSI | Oilfield wellhead equipment |
API flanges are specifically designed for high-pressure oil and gas production systems, while ASME flanges are typically used in process piping systems.
The difference between ASME/ANSI and API is the fabrication material and a higher rated API operating pressure.
ASME/ANSI flanges are commonly used in industrial process systems handling water, steam, air and gas. API flanges are manufactured for high strength operating refinery systems with products such as oil and explosive gases.
The flange standards API 6A and ASME/ANSI B16.5 have the same dimensions – but the API 6A flanges are rated for higher pressures as indicated below:
| API vs. ASME/ANSI Flanges with the same Dimensions | ||||
|---|---|---|---|---|
| Flange | Pressure Class Rating (psi) |
Nominal Size Range (inches) |
||
| ASME/ANSI B16.5 | API 6A | ASME/ANSI B16.5 | API 6A1) | |
| Weld neck | 600 | 2000 | 1/2 – 24 | 113/16 – 11 |
| 900 | 3000 | |||
| 1500 | 5000 | |||
| Blind and Threaded | 600 | 2000 | 113/16 – 211/4 | |
| 900 | 3000 | 113/16 – 203/4 | ||
| 1500 | 5000 | 113/16 – 11 | ||
1) In the old API standard, flanges ranged from 1 1/2 to 10(20) inches.
- 1 inch = 25.4 mm
We are a professional manufacturer and exporter of API 6A Type 6B Weld Neck RTJ Flanges for oilfield applications.
Our products provide:
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Strict quality control
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Multiple material options
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Custom sizes and pressure ratings
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Competitive factory pricing
All flanges can be supplied with EN 10204 3.1 mill test certificates and third-party inspection if required.
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