BS 3799 Standard
British Standard Forged Fittings
BS 3799 Standard: Dimensions | Specifications | Material Grade | About British Standard 3799 | All Product Types
The BS 3799 standard, established by the British Standards Institution, provides a comprehensive specification for forged steel pipe fittings with screwed (threaded) and socket-welding ends, designed to be used in pressure piping systems. This standard is widely accepted in industries requiring durable and high-pressure components, including oil & gas, refineries, chemical processing, power generation, and marine engineering.
BS 3799 fittings are manufactured from carbon steel, alloy steel, stainless steel, and other high-performance materials to meet the mechanical strength and pressure handling required in demanding environments. The standard outlines precise requirements for dimensions, wall thickness, thread types (typically complying with BS 21 or ISO 7/1), socket weld depths, tolerances, marking, pressure-temperature ratings, and material composition. It ensures interchangeability and global compatibility across a wide range of industrial systems.
This standard supports the manufacture of key forged fitting types such as Elbows, Tees, Couplings, Unions, Bushings, Caps, Plugs, Crosses, Bosses, and Swage Nipples, in sizes ranging from 1/8” to 4” (DN6 to DN100). Each fitting is rated typically under Class 2000, 3000, and 6000 pressure ratings, depending on the material and application requirement.
At Nutech Overseas, we manufacture and export a wide range of BS 3799-compliant forged fittings using advanced forging technology, CNC machining, and strict quality control procedures. Every fitting is hydrostatically or pneumatically tested as per client requirements and comes with full traceability, material test certificates, and compliance documentation.
Whether you require corrosion-resistant stainless steel threaded fittings or robust carbon steel socket weld elbows, our BS 3799 forged fittings ensure safety, strength, and longevity in complex piping networks.
BS 3799 Forged Pipe Fittings – Socket Weld & Threaded Fittings for High-Pressure Piping Systems
For complete technical details, including dimensions, pressure ratings, weight charts, and material specifications of our BS 3799 Standard Socket Weld and Threaded Fittings, please download the full Catalog PDF below.
Precision-Engineered BS 3799 Standard Forged Fittings in Stainless Steel, Carbon Steel, and Alloy Steel – Ensuring Reliable Flow Control in Oil & Gas, Chemical, and Power Industries
Technical Specifications of BS 3799 Standards
| Specification | Details |
|---|---|
| Standard | BS 3799 – Specification for Steel Pipe Fittings, Socket-Welding and Threaded |
| Fitting Types | Elbow, Tee, Cross, Coupling, Cap, Plug, Bushings, Union, Hex Nipple, Boss, Adapter |
| Fitting Class | Class 2000, Class 3000, Class 6000 (Threaded); Class 3000, Class 6000, Class 9000 (Socket Weld) |
| Thread Type | BSP (British Standard Pipe), NPT (National Pipe Thread) |
| Size Range | ¼" to 4" (DN 6 to DN 100) |
| Pressure Ratings | 2000#, 3000#, 6000#, 9000# |
| Design Standards | Conforming to BS 3799 requirements for dimensions, wall thickness, and tolerances |
| Manufacturing Method | Forged, Heat Treated, Machined |
| Surface Finish | Blackodised, Pickled, Bright, Rust-Proof Oil, Galvanized (on request) |
| Testing & Certification | 100% Pressure Tested, PMI, IGC, NACE MR0175, MTC as per EN 10204 3.1/3.2 |
| Application Industries | Oil & Gas, Construction, Ship Building, Power Plants, Petrochemical, Pharmaceutical, Water Treatment, Automobile, Chemical, Pulp & Paper |
| Origin | Made in India (by Nutech Overseas) |
| Export Network | USA, Europe, and Middle East |
Complete Material Grade Chart - British Standard 3799
| Material | Grades / Standards / UNS Numbers |
|---|---|
| Stainless Steel | ASTM A182 F304 / F304L, F316 / F316L, F310, F321 / F321H, F347 / F347H, SS 904L, DIN 1.4301, 1.4306, 1.4401, 1.4404 |
| Carbon Steel | ASTM A105, ASTM A106 Gr B, ASTM A234 WPB, ASTM A350 LF2 CL.1, MSS-SP-75 WPHY 42, WPHY 46, WPHY 52, WPHY 60, WPHY 65, WPHY 70 |
| Low Temperature Carbon Steel | ASTM A420 WPL3, ASTM A420 WPL6 |
| Alloy Steel | ASTM A182 F1, F5, F9, F11, F12, F22, F91, ASTM A234 WP1, WP5, WP9, WP11, WP22, WP91 |
| Duplex Steel | ASTM A815 UNS S31803, S32205, Werkstoff No. 1.4462 |
| Super Duplex Steel | ASTM A815 UNS S32750, S32760, S32950 |
| Nickel Alloys | Nickel 200 (UNS N02200), Nickel 201 (UNS N02201), Inconel 600 (UNS N06600), 601 (UNS N06601), 625 (UNS N06625), 800 (UNS N08800), 825 (UNS N08825), Monel 400 (UNS N04400), Monel K500 (UNS N05500), Hastelloy C276 (UNS N10276), Hastelloy C22 (UNS N06022), Alloy 20 (UNS N08020), Nimonic 75 / 90 |
| Copper Nickel | Cu-Ni 90/10 (C70600), Cu-Ni 70/30 (C71500), CuNi10Fe1Mn, CuNi30Mn1Fe |
| Titanium | Grade 1, Grade 2, ASTM B381 |
| Aluminium | ASTM B361, Aluminium 6061, 6082, 7075 |
| Brass | ASTM B62, C23000, C26000 |
| Bronze | Tin Bronze, Aluminium Bronze (C95400), Leaded Bronze (C93200), ASTM B148 |
| 254 SMO | UNS S31254, ASTM A182 F44 |
BS 3799 is the British Standard that specifies the requirements for forged steel pipe fittings with socket-welding and threaded connections, primarily intended for use in high-pressure piping systems. This standard outlines dimensional requirements, pressure-temperature ratings, tolerances, testing, and marking requirements. BS 3799 fittings are typically used in industries such as oil and gas, petrochemical, power generation, and marine applications, where reliable joint integrity under high pressure and temperature is essential.
Fittings manufactured according to BS 3799 undergo several mandatory tests to ensure their reliability and conformance to quality standards. These typically include:
- Hydrostatic Testing: To verify the integrity and leak-proof nature of the forged fitting under pressure.
- Non-Destructive Examination (NDE): Such as ultrasonic testing (UT) or magnetic particle inspection (MPI) to detect surface and sub-surface defects.
- Dimensional Inspection: To ensure all fittings comply precisely with BS 3799 specifications.
- Material Verification Tests: Including chemical analysis and mechanical testing (like tensile strength, yield strength, and elongation) to ensure material consistency.
These rigorous tests ensure BS 3799 fittings are safe, durable, and suitable for critical pressure piping applications.
The BS 3799 standard specifically governs the manufacture and dimensions of steel pipe fittings forged from carbon steel and alloy steel, intended primarily for use in pressure piping systems. The range of fittings under this standard typically includes tees, elbows, reducers, couplings, caps, and unions designed to handle high-pressure and high-temperature environments.
BS 3799 focuses on ensuring these forged fittings meet stringent mechanical properties, chemical composition, dimensional accuracy, and pressure ratings to provide reliability and safety in critical applications. This standard is widely adopted in oil & gas, petrochemical, power plants, and industrial sectors where robust and durable piping components are essential.
The fittings manufactured as per BS 3799 are suitable for welded, threaded, or socket weld connections, ensuring versatility for different piping configurations. The standard helps guarantee compatibility, interchangeability, and performance across various installations, making it a trusted specification for forged fittings worldwide.
Both are standards for forged fittings, but they differ in the following ways:
- Standard Origin:
- BS 3799: British Standard by BSI.
- ASME B16.11: American Standard by ASME.
- Thread Types:
- BS 3799: Typically uses BSP (British Standard Pipe) threads.
- ASME B16.11: Uses NPT (National Pipe Thread) threads.
- Dimensional Differences:
- Minor variations in size, tolerances, and pressure ratings between the two.
- Regional Preference:
- BS 3799: More common in UK, Middle East, Europe, Asia.
- ASME B16.11: Widely used in North America and projects with ANSI/ASME compliance.
- Marking & Testing:
- Both require markings, testing, and material traceability, but procedures may vary slightly.
BS 3799 forged fittings are designed for high-pressure applications. The standard typically covers the following pressure classes:
- Class 2000 – for Threaded (Screwed) Ends
- Class 3000 – for Socket Weld Ends
- Class 6000 – available in both Threaded and Socket Weld types
These pressure ratings are based on the material strength and are compatible with corresponding pipe schedules. The fittings are tested to ensure they meet the necessary leak-proof performance and mechanical integrity under elevated pressures.
These classes are widely used in critical applications across:
- Oil & Gas pipelines
- Petrochemical refineries
- Power generation plants
- Shipbuilding and marine piping systems
BS 3799 forged fittings are widely used across industries that demand high-pressure integrity, corrosion resistance, and dimensional precision. This standard is preferred for its technical robustness and global recognition. Key industries include:
- Oil & Gas (Onshore & Offshore) – Ideal for upstream and downstream systems requiring high-pressure socket weld and threaded connections.
- Petrochemical Plants – Suitable for aggressive chemical environments and compact piping arrangements.
- Power Generation – BS 3799 fittings are compatible with high-temperature, high-stress conditions in boiler and turbine piping systems.
- Marine & Shipbuilding – Excellent resistance to saltwater and pressurized fuel or hydraulic systems.
- Refineries & Chemical Processing – Trusted for leak-proof joints in corrosive or hazardous fluid applications.
The preference for BS 3799 stems from its:
- Compatibility with ANSI/ASME pipe schedules
- Strict dimensional & mechanical property standards
- Secure fitment for leak-free operations
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