WHAT IS THE ASME B16.9 STANDARD ?
The ASME B16.9 standard is a set of guidelines and specifications for the design, manufacturing, and testing of butt-welded fittings used in piping systems. This standard is published by the American Society of Mechanical Engineers (ASME) and is widely recognized and used in the industry.
The ASME B16.9 standard covers a wide range of fittings, including elbows, tees, reducers, caps, and stub ends. These fittings are used to connect pipes of different sizes and shapes, change the direction of flow, and control the flow rate of fluids in a piping system.
The ASME B16.9 standard provides detailed guidelines for the design and manufacturing of these fittings, including the materials used, the dimensions and tolerances, and the testing and inspection procedures. This standard is essential for ensuring the safety and reliability of piping systems in a wide range of industries, including oil and gas, chemical processing, power generation, and water treatment.
B16.9 – Factory-Made Wrought Buttwelding Fittings – ASME
History of the ASME B16.9 Standard
The ASME B16.9 standard has a long history dating back to the early 20th century. The first edition of the standard was published in 1927 and covered only wrought steel and wrought iron fittings. Over the years, the standard has been revised and expanded to include a wider range of materials and fittings.
The most recent edition of the ASME B16.9 standard was published in 2020 and includes updates and revisions to the previous edition. These updates reflect changes in industry practices and advances in technology, as well as feedback from users and stakeholders.
Key Features of the ASME B16.9 Standard
The ASME B16.9 standard includes a number of key features that make it an essential resource for the design and manufacturing of butt-welded fittings. These features include:
Materials: The standard specifies the materials that can be used for the manufacture of butt-welded fittings, including carbon steel, stainless steel, alloy steel, and other materials. The materials must meet certain chemical and mechanical properties to ensure the safety and reliability of the fittings.
Dimensions and Tolerances: The standard provides detailed specifications for the dimensions and tolerances of butt-welded fittings, including the outside diameter, wall thickness, center-to-end dimensions, and other critical dimensions. These specifications ensure that the fittings are compatible with the pipes they are designed to connect and that they can withstand the pressures and stresses of the piping system.
Manufacturing Processes: The standard specifies the manufacturing processes that must be used to produce butt-welded fittings, including forging, casting, and machining. These processes must be performed in accordance with industry standards and best practices to ensure the quality and reliability of the fittings.
Testing and Inspection: The standard includes detailed guidelines for the testing and inspection of butt-welded fittings, including hydrostatic testing, radiographic testing, and visual inspection. These tests and inspections are essential for ensuring the safety and reliability of the fittings and for detecting any defects or flaws that could compromise their performance.
Benefits of the ASME B16.9 Standard
The ASME B16.9 standard provides a number of benefits to the industry and to users of butt-welded fittings. These benefits include:
Safety: The standard ensures that butt-welded fittings are designed, manufactured, and tested to meet strict safety standards. This helps to prevent accidents and injuries in piping systems and ensures the safety of workers and the public.
Reliability: The standard ensures that butt-welded fittings are designed and manufactured to withstand the pressures and stresses of piping systems. This helps to prevent leaks, failures, and other problems that can disrupt operations and cause downtime.
Compatibility: The standard ensures that butt-welded fittings are compatible with the pipes they are designed to connect. This helps to ensure that piping systems are efficient and effective, and that they can be easily maintained and repaired.
Quality: The standard ensures that butt-welded fittings are manufactured to high-quality standards using the best materials and manufacturing processes. This helps to ensure that the fittings are durable, long-lasting, and perform well over time.
Conclusion
The ASME B16.9 standard is an essential resource for the design, manufacturing, and testing of butt-welded fittings used in piping systems. This standard provides detailed guidelines for the materials, dimensions, manufacturing processes, and testing and inspection procedures for these fittings, ensuring their safety, reliability, compatibility, and quality.
The ASME B16.9 standard has a long history dating back to the early 20th century and has been revised and updated over the years to reflect changes in industry practices and advances in technology. The most recent edition of the standard was published in 2020 and includes updates and revisions to the previous edition.
The ASME B16.9 standard is widely recognized and used in the industry and is essential for ensuring the safety and reliability of piping systems in a wide range of industries, including oil and gas, chemical processing, power generation, and water treatment.
what is difference between ASME B16 and ANSI B16 Standards for Pipes and Fittings?
ASME B16 and ANSI B16 are both standards for pipes and fittings, but they are developed by different organizations and have some differences in their scope and requirements.
ASME B16 standards are developed by the American Society of Mechanical Engineers (ASME) and cover a wide range of piping components, including flanges, valves, fittings, and gaskets. These standards are widely used in the oil and gas, chemical, and power industries, among others. ASME B16 standards are generally more stringent than ANSI B16 standards in terms of material requirements, testing, and quality control.
ANSI B16 standards, on the other hand, are developed by the American National Standards Institute (ANSI) and cover a narrower range of piping components, including flanges and fittings. These standards are widely used in the construction and building industries. ANSI B16 standards are generally less stringent than ASME B16 standards in terms of material requirements, testing, and quality control.
In summary, ASME B16 standards are more comprehensive and rigorous than ANSI B16 standards, but both are widely used and accepted in their respective industries.
| Materials-Standards for ASME B16.9 Fittings | |
|---|---|
| ASTM Standards | Material Specification |
| A234 | Wrought Carbon Steel and Alloy Steel for Moderate and High Temperature Service |
| A403 | Wrought Austenitic Stainless Steel Piping Fittings |
| A420 | Wrought Carbon Steel and Alloy Steel for Low Temperature Service |
| A815 | Wrought Ferritic, Ferritic/Austenitic, and Martensitic Stainless Steel Piping Fittings |
| A361 | Wrought Aluminum and Aluminum Alloy Welding Fittings |
| A363 | Seamless and Welded Unalloyed Titanium and Titanium Alloy Welding Fittings |
| A366 | Wrought Nickel and Nickel Alloy Fittings |
Products-Dimensions Table
| ASME B16.9 Butt Welding Pipe Fittings Dimension Table | ||
|---|---|---|
| Long Radius Elbows | Long Radius Reducing Elbows | Long Radius Returns |
| Short Radius 180-deg Returns | 3D Elbows | Straight Tees and Crosses |
| Lap Joint Stub Ends | Caps | Reducers |
| Short Radius Elbows | Reducing Tees and Reducing Crosses | Induction Bends |
*The induction bends shall be manufactured to ASME B16.49.
*The values of dimensions & tolerances are stated separately in SI(metric) units or US Customary units.
Dimension Tolerances of ASME B16.9 Pipe Fittings
1. General Tolerances for All Fittings of ASME B16.9
| NPS | DN | O.D | I.D | Off Angle, Q | Off Plane, P |
|---|---|---|---|---|---|
| 1/2~2-1/2 | 15~65 | +1.6, -0.8 | ±0.8 | ±1 | ±2 |
| 3~3-1/2 | 80~90 | ±1.6 | ±1.6 | ±2 | ±4 |
| 4 | 100 | ±1.6 | ±1.6 | ±3 | ±5 |
| 5~8 | 125~200 | +2.4, -1.6 | ±1.6 | ±3 | ±6 |
| 10~18 | 250~450 | +4.0, -3.2 | ±3.2 | ±4 | ±10 |
| 20~24 | 500~600 | +6.4, -4.8 | ±4.8 | ±5 | ±10 |
| 26~30 | 650~750 | +6.4, -4.8 | ±4.8 | ±5 | ±13 |
| 32~48 | 800~1200 | +6.4, -4.8 | ±4.8 | ±5 | ±19 |
*All dimensions are in mm unit. NPS: Nominal Pipe Size; DN: Nominal Diameter.
*O.D: outside diameter at bevel; I.D: inside diameter at end; Both P & Q are angularity tolerances.
*A minimum wall thickness of 87.5% should apply unless otherwise specified by the purchaser.
2. Tolerances of Center-to-End & Overall Length Dimensions
| NPS | DN | *I | *II | *III | *IV |
|---|---|---|---|---|---|
| 1/2~2-1/2 | 15~65 | ±2 | ±3 | ±2 | ±3 |
| 3~3-1/2 | 80~90 | ±2 | ±3 | ±2 | ±3 |
| 4 | 100 | ±2 | ±3 | ±2 | ±3 |
| 5~8 | 125~200 | ±2 | ±3 | ±2 | ±6 |
| 10~18 | 250~450 | ±2 | ±3 | ±2 | ±6 |
| 20~24 | 500~600 | ±2 | ±3 | ±2 | ±6 |
| 26~30 | 650~750 | ±3 | ±6 | ±5 | ±10 |
| 32~48 | 800~1200 | ±5 | ±6 | ±5 | ±10 |
*All dimensions are in mm unit.
*I refers to the tolerances for center-to-end dimensions of 90° & 45° long and short radius elbows and tees, A, B, C, M.
*II refers to the tolerances for center-to-end dimensions of 3D radius elbows, A, B.
*III refers to the tolerances for overall length of reducers and lap joint stub ends, F, H.
*IV refers to the tolerances for overall length of caps, E.
3. Tolerances for 180° Returns & Lap Joint Stub Ends
| NPS | DN | 180° Return | Lap Joint Stub Ends | ||||
|---|---|---|---|---|---|---|---|
| inch | mm | O | K | U | G | R | T |
| 1/2~2-1/2 | 15~65 | ±6 | ±6 | ±1 | +0, -1 | +0, -1 | +1.6, -0 |
| 3~3-1/2 | 80~90 | ±6 | ±6 | ±1 | +0, -1 | +0, -1 | +1.6, -0 |
| 4 | 100 | ±6 | ±6 | ±1 | +0, -1 | +0, -2 | +1.6, -0 |
| 5~8 | 125~200 | ±6 | ±6 | ±1 | +0, -1 | +0, -2 | +1.6, -0 |
| 10~18 | 250~450 | ±10 | ±6 | ±2 | +0, -2 | +0, -2 | +3.2, -0 |
| 20~24 | 500~600 | ±10 | ±6 | ±2 | +0, -2 | +0, -2 | +3.2, -0 |
*All dimensions are in mm unit.
*O:center-to-center dimensions; K:back-to-face dimensions; U:alignment of ends.
*G:outside diameter of lap; R:fillet radius of lap; T:Lap thickness.