ANSI / ASME B16.5 Class 300 Lap Joint Flange Dimensions
Lap Joint flanges are commonly used in low-pressure, non-corrosive medium systems, such as in industries like food processing, pharmaceuticals, and water treatment.
ANSI / ASME B16.5 Class 300 Lap Joint Flange
| Nominal Pipe Size | Outside Diameter (O) | Thickness (T) | Length Thru Hub (Y) | Hub Diameter (X) | Radius (r) | Bore (B) | Approximate Weight (lbs) | Bolt Circle (C) | Number of Holes | Diameter of Holes |
| 1/2 | 3.75 | 0.56 | 0.88 | 1.50 | 0.13 | 0.90 | 2 | 2.63 | 4 | 0.63 |
| 3/4 | 4.63 | 0.63 | 1.00 | 1.88 | 0.13 | 1.11 | 3 | 3.25 | 4 | 0.75 |
| 1 | 4.88 | 0.69 | 1.06 | 2.13 | 0.13 | 1.38 | 3 | 3.50 | 4 | 0.75 |
| 1 1/4 | 5.25 | 0.75 | 1.06 | 2.50 | 0.19 | 1.72 | 4 | 3.88 | 4 | 0.75 |
| 1 1/2 | 6.13 | 0.81 | 1.19 | 2.75 | 0.25 | 1.97 | 6 | 4.50 | 4 | 0.88 |
| 2 | 6.50 | 0.88 | 1.31 | 3.31 | 0.31 | 2.46 | 7 | 5.00 | 8 | 0.75 |
| 2 1/2 | 7.50 | 1.00 | 1.50 | 3.94 | 0.31 | 2.97 | 10 | 5.88 | 8 | 0.88 |
| 3 | 8.25 | 1.13 | 1.69 | 4.63 | 0.38 | 3.60 | 13 | 6.63 | 8 | 0.88 |
| 3 1/2 | 9.00 | 1.19 | 1.75 | 5.25 | 0.44 | 4.10 | 17 | 7.25 | 8 | 0.88 |
| 4 | 10.00 | 1.25 | 1.88 | 5.75 | 0.44 | 4.60 | 22 | 7.88 | 8 | 0.88 |
| 5 | 11.00 | 1.38 | 2.00 | 7.00 | 0.44 | 5.69 | 28 | 9.25 | 8 | 0.88 |
| 6 | 12.50 | 1.44 | 2.06 | 8.13 | 0.50 | 6.75 | 39 | 10.63 | 12 | 0.88 |
| 8 | 15.00 | 1.63 | 2.44 | 10.25 | 0.50 | 8.75 | 58 | 13.00 | 12 | 1.00 |
| 10 | 17.50 | 1.88 | 3.75 | 12.63 | 0.50 | 10.92 | 91 | 15.25 | 16 | 1.13 |
| 12 | 20.50 | 2.00 | 4.00 | 14.75 | 0.50 | 12.92 | 140 | 17.75 | 16 | 1.25 |
| 14 | 23.00 | 2.13 | 4.38 | 16.75 | 0.50 | 14.18 | 190 | 20.25 | 20 | 1.25 |
| 16 | 25.50 | 2.25 | 4.75 | 19.00 | 0.50 | 16.19 | 250 | 22.50 | 20 | 1.38 |
| 18 | 28.00 | 2.38 | 5.13 | 21.00 | 0.50 | 18.20 | 295 | 24.75 | 24 | 1.38 |
| 20 | 30.50 | 2.50 | 5.50 | 23.13 | 0.50 | 20.25 | 370 | 27.00 | 24 | 1.38 |
| 22 | 33.00 | 2.63 | 5.75 | 25.25 | 0.50 | 22.25 | 435 | 29.25 | 24 | 1.63 |
| 24 | 36.00 | 2.75 | 6.00 | 27.63 | 0.50 | 24.25 | 550 | 32.00 | 24 | 1.63 |
| Nominal Pipe Size | Outside Diameter (O) | Thickness (T) | Length Thru Hub (Y) | Hub Diameter (X) | Radius (r) | Bore (B) | Approximate Weight (lbs) | Bolt Circle (C) | Number of Holes | Diameter of Holes |
| 1/2 | 95.25 | 14.22 | 22.35 | 38.10 | 3.30 | 22.86 | 0.91 | 66.80 | 4 | 16.00 |
| 3/4 | 117.60 | 16.00 | 25.40 | 47.75 | 3.30 | 28.19 | 1.36 | 82.55 | 4 | 19.05 |
| 1 | 123.95 | 17.53 | 26.92 | 54.10 | 3.30 | 35.05 | 1.36 | 88.90 | 4 | 19.05 |
| 1 1/4 | 133.35 | 19.05 | 26.92 | 63.50 | 4.83 | 43.69 | 1.81 | 98.55 | 4 | 19.05 |
| 1 1/2 | 155.70 | 20.57 | 30.23 | 69.85 | 6.35 | 50.04 | 2.72 | 114.30 | 4 | 22.35 |
| 2 | 165.10 | 22.35 | 33.27 | 84.07 | 7.87 | 62.48 | 3.18 | 127.00 | 8 | 19.05 |
| 2 1/2 | 190.50 | 25.40 | 38.10 | 100.08 | 7.87 | 75.44 | 4.54 | 149.35 | 8 | 22.35 |
| 3 | 209.55 | 28.70 | 42.93 | 117.60 | 9.65 | 91.44 | 5.90 | 168.40 | 8 | 22.35 |
| 3 1/2 | 228.60 | 30.23 | 44.45 | 133.35 | 11.18 | 104.14 | 7.71 | 184.15 | 8 | 22.35 |
| 4 | 254.00 | 31.75 | 47.75 | 146.05 | 11.18 | 116.84 | 9.98 | 200.15 | 8 | 22.35 |
| 5 | 279.40 | 35.05 | 50.80 | 177.80 | 11.18 | 144.53 | 12.70 | 234.95 | 8 | 22.35 |
| 6 | 317.50 | 36.58 | 52.32 | 206.50 | 12.70 | 171.45 | 17.69 | 270.00 | 12 | 22.35 |
| 8 | 381.00 | 41.40 | 61.98 | 260.35 | 12.70 | 222.25 | 26.31 | 330.20 | 12 | 25.40 |
| 10 | 444.50 | 47.75 | 95.25 | 320.80 | 12.70 | 277.37 | 41.28 | 387.35 | 16 | 28.70 |
| 12 | 520.70 | 50.80 | 101.60 | 374.65 | 12.70 | 328.17 | 63.50 | 450.85 | 16 | 31.75 |
| 14 | 584.20 | 54.10 | 111.25 | 425.45 | 12.70 | 360.17 | 86.18 | 514.35 | 20 | 31.75 |
| 16 | 647.70 | 57.15 | 120.65 | 482.60 | 12.70 | 411.23 | 113.40 | 571.50 | 20 | 35.05 |
| 18 | 711.20 | 60.45 | 130.30 | 533.40 | 12.70 | 462.28 | 133.81 | 628.65 | 24 | 35.05 |
| 20 | 774.70 | 63.50 | 139.70 | 587.50 | 12.70 | 514.35 | 167.83 | 685.80 | 24 | 35.05 |
| 22 | 838.20 | 66.80 | 146.05 | 641.35 | 12.70 | 565.15 | 197.31 | 742.95 | 24 | 41.40 |
| 24 | 914.40 | 69.85 | 152.40 | 701.80 | 12.70 | 615.95 | 249.47 | 812.80 | 24 | 41.40 |
ANSI / ASME B16.5 Class 300 Lap Joint Flange is a flange that conforms to the ANSI / ASME B16.5 standard with a pressure rating of Class 300. It typically consists of two parts: a flat flange and a loose fitting lap joint ring that can slide over the flange. This design allows for easy alignment and installation of pipes by adjusting the position of the lap joint ring, making it easier to disassemble and maintain. Class 300 indicates that the flange is rated for a maximum working pressure of 300 pounds per square inch (psi) at standard temperatures.
For more technical support, please contact SSM.
FAQ
The primary advantages are ease of installation, disassembly, and maintenance, making them ideal for systems where frequent maintenance is needed. They also allow for flexibility in pipe alignment.
Yes, Class 300 Lap Joint Flanges are generally compatible with other flanges of the same pressure rating and size, though the lap joint ring must match the pipe’s material and dimensions for proper fitment.
They are typically made from materials like carbon steel, stainless steel, or alloy steels, depending on the application and environmental conditions.
EN 
DE 
RU 
FA 
ID 
ES 
FR 
NL