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February 11, 2026Stainless Steel Long Weld Neck Flanges Weight Chart is a very important reference material applied in industrial piping systems to provide structural accuracy, load control, and safety of installation. Long weld neck flanges are designed to meet high-pressure and high-temperature service, which requires weight calculation to be critical in terms of system reliability and performance.
What Are Stainless Steel Long Weld Neck Flanges?
The stainless steel long weld neck flanges have a long tapered hub, which progressively changes to the thickness of the pipe wall. This special structure minimizes stress concentration in the joint and entails fatigue resistance. These flanges find high application in oil refineries, petrochemical plants, power stations, and offshore pipelines, which are critical.
Their long neck gives them a superior reinforcement that they are applicable in systems that experience cyclic loading and harsh operating environments.
Long Weld Neck Flange Dimension Chart
| Size mm | Size Inch | Flange Thickness | Outer Diameter | Hub OD | Weld Neck OD | RF Height | RF Diameter | RF Stud Length | PCD | Size Bolt | No of Bolts | Hole Size |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| B | A | C | D | F | E | G | ||||||
| 25 | 1 | 12.7 | 110 | 49 | 33.4 | 2 | 50.8 | 65 | 79.4 | 1/2 | 4 | 5/8 |
| 600 | 24 | 46.1 | 815 | 663 | 610 | 2 | 692.2 | 170 | 749.3 | 1 1/4 | 20 | 1 3/8 |
| 200 | 8 | 27 | 345 | 246 | 219.1 | 2 | 269.9 | 110 | 298.5 | 3/4 | 8 | 7/8 |
| 32 | 1 1/4 | 14.3 | 115 | 59 | 42.2 | 2 | 63.5 | 70 | 88.9 | 1/2 | 4 | 5/8 |
| 125 | 5 | 22.3 | 255 | 164 | 141.3 | 2 | 185.7 | 95 | 215.9 | 3/4 | 8 | 7/8 |
| 450 | 18 | 38.1 | 635 | 505 | 457.2 | 2 | 533.4 | 145 | 577.9 | 1 1/8 | 16 | 1 1/4 |
| 150 | 6 | 23.9 | 280 | 192 | 168.3 | 2 | 215.9 | 100 | 241.3 | 3/4 | 8 | 7/8 |
| 15 | 1/2 | 9.6 | 90 | 30 | 21.3 | 2 | 34.9 | 55 | 60.3 | 1/2 | 4 | 5/8 |
| 300 | 12 | 30.2 | 485 | 365 | 323.8 | 2 | 381 | 120 | 431.8 | 7/8 | 12 | 1 |
| 90 | 3 1/2 | 22.3 | 215 | 122 | 101.6 | 2 | 139.7 | 90 | 177.8 | 5/8 | 8 | 3/4 |
| 350 | 14 | 33.4 | 535 | 400 | 355.6 | 2 | 412.8 | 135 | 476.3 | 1 | 12 | 1 1/8 |
| 20 | 3/4 | 11.2 | 100 | 38 | 26.7 | 2 | 42.9 | 65 | 69.9 | 1/2 | 4 | 5/8 |
| 40 | 1 1/2 | 15.9 | 125 | 65 | 48.3 | 2 | 73 | 70 | 98.4 | 1/2 | 4 | 5/8 |
| 80 | 3 | 22.3 | 190 | 108 | 88.9 | 2 | 127 | 90 | 152.4 | 5/8 | 4 | 3/4 |
| 100 | 4 | 22.3 | 230 | 135 | 114.3 | 2 | 157.2 | 90 | 190.5 | 5/8 | 8 | 3/4 |
| 50 | 2 | 17.5 | 150 | 78 | 60.3 | 2 | 92.1 | 85 | 120.7 | 5/8 | 4 | 3/4 |
| 500 | 20 | 41.3 | 700 | 559 | 508 | 2 | 584.2 | 160 | 635 | 1 1/8 | 20 | 1 1/4 |
| 65 | 2 1/2 | 20.7 | 180 | 90 | 73 | 2 | 104.8 | 90 | 139.7 | 5/8 | 4 | 3/4 |
| 250 | 10 | 28.6 | 405 | 305 | 273 | 2 | 323.8 | 115 | 362 | 7/8 | 12 | 1 |
| 400 | 16 | 35 | 595 | 457 | 406.4 | 2 | 469.9 | 135 | 539.8 | 1 | 16 | 1 1/8 |

Significance of Long Weld Neck Flanges: Stainless Steel Long Weld Neck Flange Weight Chart.
An S.S. Long Weld Neck Flanges Weight Chart is standardized weight information in terms of flange size, pressure class, and dimensional requirements. Engineering, safety of handling, and effective project implementation require the accuracy of weight-related information.
Weight charts enable engineers to identify the support required by pipes and the structural loads, and also align the installation correctly. Inaccurate weight information can result in imbalance in the piping systems, overstress, or performance problems over time.

The effectors on the long weld neck flange weigh.
Several technical considerations affect the total weight of stainless steel long weld neck flanges:
- Material Grade: Some of the grades are 304, 316, 321, and 347, which influence density and strength.
- Pressure Class: The pressure rating that requires high demands for greater thickness of dimensions.
- Nominal Pipe Size: Bigger sizes make more metal and a larger flange diameter.
- Standards of Manufacturing ASME B16.5 and ASME B16.47 specify dimensional tolerances.
- All these parameters should be taken into account when a Stainless Steel Long Weld Neck Flange Weight Chart is referred to.
Stainless Steel Long Weld Neck Flanges Weight in KG
| NOMINAL SIZE | DIMENSIONS | WEIGHT (KG) | ||||
|---|---|---|---|---|---|---|
| NPS (Inches) | DN (mm) | FLANGE MM | FLANGE THICKNESS | SOW SW | WN | BLIND |
| 1/2 | 15 | 88.9 | 11.2 | 0.4 | 0.5 | 0.4 |
| 3/4 | 20 | 98.6 | 12.7 | 0.6 | 0.7 | 0.6 |
| 1 | 25 | 108 | 14.2 | 0.8 | 1 | 0.9 |
| 1 1/4 | 32 | 117.3 | 15.7 | 1 | 1.3 | 1.2 |
| 1 1/2 | 40 | 127 | 17.5 | 1.3 | 1.7 | 1.5 |
| 2 | 50 | 152.4 | 19.1 | 2.1 | 2.6 | 2.4 |
| 2 1/2 | 65 | 177.8 | 22.4 | 3.3 | 4.1 | 3.9 |
| 3 | 80 | 190.5 | 23.9 | 3.9 | 4.9 | 4.9 |
| 3 1/2 | 90 | 215.9 | 23.9 | 4.8 | 6.1 | 6.2 |
| 4 | 100 | 228.6 | 23.9 | 5.3 | 6.8 | 7.0 |
| 5 | 125 | 254 | 23.9 | 6.1 | 8.6 | 8.6 |
| 6 | 150 | 279.4 | 25.4 | 7.5 | 10.6 | 11.3 |
| 8 | 200 | 342.9 | 28.4 | 12.1 | 17.6 | 19.6 |
| 10 | 250 | 406.4 | 30.2 | 16.5 | 24 | 28.6 |
| 12 | 300 | 482.6 | 31.8 | 26.2 | 36.5 | 43.2 |
| 14 | 350 | 533.4 | 35.1 | 34.6 | 48.4 | 58.1 |
| 16 | 400 | 596.9 | 36.6 | 44.8 | 60.6 | 76.1 |
| 18 | 450 | 635 | 39.6 | 48.9 | 68.3 | 93.7 |
| 20 | 500 | 698.5 | 42.9 | 61.9 | 84.5 | 122.0 |
| 24 | 600 | 812.8 | 47.8 | 86.9 | 115 | 185.0 |
Industrial Significance of Weight Charts.
Weight charts are broadly employed in the industries in the planning, execution, and quality assurance.
Accuracy of Engineering and Design.
Weight charts are used to enable engineers to determine the spread of stress and the span and spacing of the pipes.
Installation and Safety
The accurate knowledge of the flange weight will help to use the right lifting equipment and will reduce the risks at the site.
Cost and Logistics Planning.
The correct weight information assists in the determination of the transportation expenses and avoids unforeseen handling problems.

Benefits of Stainless Steel Long Weld Neck Flanges.
Long weld neck flanges made of stainless steel present several benefits of performance:
- Outstanding mechanical hardiness and stability.
- Easy movement of stress at the welded joints.
- Very low corrosion and temperature.
- Prolonged operation under harsh conditions.
- Less chance of leaking and joint failure.
Such advantages make them best suited to important pipeline applications.
Routine Uses of Long Weld Neck Flanges.
Long weld neck flanges of stainless steel are used in:
- Oil and gas refining plants.
- Distribution of chemical and petrochemical plants.
- Power generation systems
- The offshore and marine pipelines.
- Fluid lines and high-pressure steam.
Stainless Steel Long Weld Neck Flanges Specifications
Stainless Steel Long Weld Neck Flanges are manufactured as per the following international standards and specifications:
| Specification | Description |
|---|---|
| ASME SA182 | Forged or rolled alloy and Stainless Steel Long Weld Neck Flanges for high-temp service |
| ASTM A182 | Standard for SS 304, SS 316, SS 316Ti, and alloy flanges |
| ASME B16.5 | Covers dimensions and pressure classes for sizes NPS ½″ to 24″ |
| EN 1092-1 | European standard for flanges and bolting |
| DIN | German flange standards (common in Europe and Asia) |
| MSS-SP44 | Steel pipe line flanges for oil and gas transmission |
| API 605 | Large-diameter carbon and stainless steel flanges |
Conclusion
A properly designed Stainless Steel Long Weld Neck Flanges Weight Chart is an essential part of the design and implementation of effective piping systems. Precise weight information facilitates safe installation, acceptable calculation of load, and efficient operations in the long term. With standardized weight charts and high-quality stainless steel flanges, industries can have high safety, minimized maintenance, and reliable performance in the high pressure and high-temperature use.
