90° Long Radius Elbow Dimensions
The long radius 90° elbow is the default turn in industrial piping. Its centerline radius is 1.5 times the nominal pipe diameter, gentle enough to keep pressure drop and erosion low, while still fitting normal pipe rack spacing. When a drawing says "90 ell" with no other qualifier, this is almost always the part meant.
Why 1.5D is the default.
The wider sweep of a long radius elbow means less turbulence, lower pressure loss, and less wall erosion than a short radius turn. In abrasive or high-velocity service that difference shows up directly as service life, which is why most piping specs call long radius unless space forces the tighter option.
Reading the center-to-end.
The C dimension is measured from the theoretical intersection of the two centerlines to the face of either end. It is the number you need for spool fabrication and takeoff, and on a standard long radius elbow it equals 1.5 × NPS.
How To Read These Dimensions
ASME B16.9 is the dimensional standard for factory-made wrought buttwelding fittings, and the long radius elbow is its centrepiece: the 1.5D centerline radius, the center-to-end C below, and the tolerances on both come from it. Welding ends are prepared to ASME B16.25.
- O.D.
- Outside diameterOutside diameter at the welding end, matching the pipe it welds to.
- I.D.
- Inside diameterBore through the fitting, set by the wall thickness.
- T
- Wall thicknessNominal wall at the welding end, matched to the pipe schedule.
- C
- Center to endFrom the theoretical intersection of the two centerlines to the welding face. On a long radius 90 it equals 1.5 times the nominal size.
121 sizes across 6 schedules · dimensions in inches, weights in pounds · ASME B16.9
Schedule STD
| Nom. Pipe Size | Outside Diameter O.D. | Inside Diameter I.D. | Wall Thickness T | Center to End C | Pipe Schedule Number | Approx. Weight in Pounds Lbs. |
|---|---|---|---|---|---|---|
| ½ | 0.84 | 0.622 | 0.109 | 1.50 | 40 | 0.16 |
| ¾ | 1.05 | 0.824 | 0.113 | 1.50 | 40 | 0.17 |
| 1 | 1.32 | 1.049 | 0.133 | 1.50 | 40 | 0.40 |
| 1¼ | 1.66 | 1.380 | 0.140 | 1.88 | 40 | 0.55 |
| 1½ | 1.90 | 1.610 | 0.145 | 2.25 | 40 | 0.80 |
| 2 | 2.38 | 2.067 | 0.154 | 3.00 | 40 | 1.60 |
| 2½ | 2.88 | 2.469 | 0.203 | 3.75 | 40 | 3.20 |
| 3 | 3.50 | 3.068 | 0.216 | 4.50 | 40 | 4.80 |
| 3½ | 4.00 | 3.548 | 0.226 | 5.25 | 40 | 6.60 |
| 4 | 4.50 | 4.026 | 0.237 | 6.00 | 40 | 8.90 |
| 5 | 5.56 | 5.047 | 0.258 | 7.50 | 40 | 15.10 |
| 6 | 6.62 | 6.065 | 0.280 | 9.00 | 40 | 24.00 |
| 8 | 8.62 | 7.981 | 0.322 | 12.00 | 40 | 47.80 |
| 10 | 10.75 | 10.020 | 0.365 | 15.00 | 40 | 83.40 |
| 12 | 12.75 | 12.000 | 0.375 | 18.00 | * | 123.00 |
| 14 | 14.00 | 13.250 | 0.375 | 21.00 | 30 | 155.00 |
| 16 | 16.00 | 15.250 | 0.375 | 24.00 | 30 | 206.00 |
| 18 | 18.00 | 17.250 | 0.375 | 27.00 | * | 262.00 |
| 20 | 20.00 | 19.250 | 0.375 | 30.00 | 20 | 324.00 |
| 24 | 24.00 | 23.250 | 0.375 | 36.00 | 20 | 466.00 |
| 30 | 30.00 | 29.250 | 0.375 | 45.00 | * | 720.00 |
| 36 | 36.00 | 35.250 | 0.375 | 54.00 | * | 1039.00 |
| 42 | 42.00 | 41.250 | 0.375 | 63.00 | * | 1420.00 |
| 48 | 48.00 | 47.250 | 0.375 | 72.00 | * | 2000.00 |
Schedule XS
| Nom. Pipe Size | Outside Diameter O.D. | Inside Diameter I.D. | Wall Thickness T | Center to End C | Pipe Schedule Number | Approx. Weight in Pounds Lbs. |
|---|---|---|---|---|---|---|
| ½ | 0.84 | 0.546 | 0.147 | 1.50 | 80 | 0.26 |
| ¾ | 1.05 | 0.742 | 0.154 | 1.50 | 80 | 0.29 |
| 1 | 1.32 | 0.957 | 0.179 | 1.50 | 80 | 0.48 |
| 1¼ | 1.66 | 1.278 | 0.191 | 1.88 | 80 | 0.79 |
| 1½ | 1.90 | 1.500 | 0.200 | 2.25 | 80 | 1.20 |
| 2 | 2.38 | 1.939 | 0.218 | 3.00 | 80 | 2.10 |
| 2½ | 2.88 | 2.323 | 0.276 | 3.75 | 80 | 3.80 |
| 3 | 3.50 | 2.900 | 0.300 | 4.50 | 80 | 6.30 |
| 3½ | 4.00 | 3.364 | 0.318 | 5.25 | 80 | 8.60 |
| 4 | 4.50 | 3.826 | 0.337 | 6.00 | 80 | 12.50 |
| 5 | 5.56 | 4.813 | 0.375 | 7.50 | 80 | 21.20 |
| 6 | 6.62 | 5.761 | 0.432 | 9.00 | 80 | 34.40 |
| 8 | 8.62 | 7.625 | 0.500 | 12.00 | 80 | 71.30 |
| 10 | 10.75 | 9.750 | 0.500 | 15.00 | 60 | 111.00 |
| 12 | 12.75 | 11.750 | 0.500 | 18.00 | * | 158.00 |
| 14 | 14.00 | 13.000 | 0.500 | 21.00 | * | 201.00 |
| 16 | 16.00 | 15.000 | 0.500 | 24.00 | 40 | 270.00 |
| 18 | 18.00 | 17.000 | 0.500 | 27.00 | * | 348.00 |
| 20 | 20.00 | 19.000 | 0.500 | 30.00 | 30 | 422.00 |
| 24 | 24.00 | 23.000 | 0.500 | 36.00 | * | 604.00 |
| 30 | 30.00 | 29.000 | 0.500 | 45.00 | 20 | 997.00 |
| 36 | 36.00 | 35.000 | 0.500 | 54.00 | 20 | 1380.00 |
| 42 | 42.00 | 41.000 | 0.500 | 63.00 | * | 1880.00 |
| 48 | 48.00 | 47.000 | 0.500 | 72.00 | * | 2502.00 |
Schedule 40
| Nom. Pipe Size | Outside Diameter O.D. | Inside Diameter I.D. | Wall Thickness T | Center to End C | Pipe Schedule Number | Approx. Weight in Pounds Lbs. |
|---|---|---|---|---|---|---|
| ½ | 0.84 | 0.622 | 0.109 | 1.50 | 40 | 0.16 |
| ¾ | 1.05 | 0.824 | 0.113 | 1.50 | 40 | 0.17 |
| 1 | 1.32 | 1.054 | 0.133 | 1.50 | 40 | 0.40 |
| 1¼ | 1.66 | 1.380 | 0.140 | 1.88 | 40 | 0.55 |
| 1½ | 1.90 | 1.610 | 0.145 | 2.25 | 40 | 0.80 |
| 2 | 2.38 | 2.072 | 0.154 | 3.00 | 40 | 1.60 |
| 2½ | 2.88 | 2.474 | 0.203 | 3.75 | 40 | 3.20 |
| 3 | 3.50 | 3.068 | 0.216 | 4.50 | 40 | 4.80 |
| 3½ | 4.00 | 3.548 | 0.226 | 5.25 | 40 | 6.60 |
| 4 | 4.50 | 4.026 | 0.237 | 6.00 | 40 | 8.90 |
| 5 | 5.56 | 5.044 | 0.258 | 7.50 | 40 | 15.10 |
| 6 | 6.62 | 6.060 | 0.280 | 9.00 | 40 | 24.00 |
| 8 | 8.62 | 7.976 | 0.322 | 12.00 | 40 | 47.80 |
| 10 | 10.75 | 10.020 | 0.365 | 15.00 | 40 | 83.40 |
| 12 | 12.75 | 11.938 | 0.406 | 18.00 | 40 | 123.00 |
| 14 | 14.00 | 13.124 | 0.438 | 21.00 | 40 | 155.00 |
| 16 | 16.00 | 15.000 | 0.500 | 24.00 | 40 | 206.00 |
| 18 | 18.00 | 16.876 | 0.562 | 27.00 | 40 | 262.00 |
| 20 | 20.00 | 18.812 | 0.594 | 30.00 | 40 | 324.00 |
| 24 | 24.00 | 22.624 | 0.688 | 36.00 | 40 | 466.00 |
Schedule 80
| Nom. Pipe Size | Outside Diameter O.D. | Inside Diameter I.D. | Wall Thickness T | Center to End C | Pipe Schedule Number | Approx. Weight in Pounds Lbs. |
|---|---|---|---|---|---|---|
| ½ | 0.84 | 0.546 | 0.147 | 1.50 | 80 | 0.26 |
| ¾ | 1.05 | 0.742 | 0.154 | 1.50 | 80 | 0.29 |
| 1 | 1.32 | 0.962 | 0.179 | 1.50 | 80 | 0.48 |
| 1¼ | 1.66 | 1.278 | 0.191 | 1.88 | 80 | 0.79 |
| 1½ | 1.90 | 1.500 | 0.200 | 2.25 | 80 | 1.20 |
| 2 | 2.38 | 1.944 | 0.218 | 3.00 | 80 | 2.10 |
| 2½ | 2.88 | 2.328 | 0.276 | 3.75 | 80 | 3.80 |
| 3 | 3.50 | 2.900 | 0.300 | 4.50 | 80 | 6.30 |
| 3½ | 4.00 | 3.364 | 0.318 | 5.25 | 80 | 8.60 |
| 4 | 4.50 | 3.826 | 0.337 | 6.00 | 80 | 12.50 |
| 5 | 5.56 | 4.810 | 0.375 | 7.50 | 80 | 21.20 |
| 6 | 6.62 | 5.756 | 0.432 | 9.00 | 80 | 34.40 |
| 8 | 8.62 | 7.620 | 0.500 | 12.00 | 80 | 71.30 |
| 10 | 10.75 | 9.562 | 0.594 | 15.00 | 80 | 111.00 |
| 12 | 12.75 | 11.374 | 0.688 | 18.00 | 80 | 158.00 |
| 14 | 14.00 | 12.500 | 0.750 | 21.00 | 80 | 201.00 |
| 16 | 16.00 | 14.312 | 0.844 | 24.00 | 80 | 270.00 |
| 18 | 18.00 | 16.124 | 0.938 | 27.00 | 80 | 348.00 |
| 20 | 20.00 | 17.938 | 1.031 | 30.00 | 80 | 422.00 |
| 24 | 24.00 | 21.562 | 1.219 | 36.00 | 80 | 604.00 |
Schedule 160
| Nom. Pipe Size | Outside Diameter O.D. | Inside Diameter I.D. | Wall Thickness T | Center to End C | Pipe Schedule Number | Approx. Weight in Pounds Lbs. |
|---|---|---|---|---|---|---|
| ½ | 0.84 | 0.464 | 0.188 | 1.50 | 160 | 0.60 |
| ¾ | 1.05 | 0.612 | 0.219 | 1.50 | 160 | 0.60 |
| 1 | 1.32 | 0.820 | 0.250 | 1.50 | 160 | 0.60 |
| 1¼ | 1.66 | 1.160 | 0.250 | 1.88 | 160 | 1.00 |
| 1½ | 1.90 | 1.338 | 0.281 | 2.25 | 160 | 1.80 |
| 2 | 2.38 | 1.692 | 0.344 | 3.00 | 160 | 3.20 |
| 2½ | 2.88 | 2.130 | 0.375 | 3.75 | 160 | 6.00 |
| 3 | 3.50 | 2.624 | 0.438 | 4.50 | 160 | 10.00 |
| 4 | 4.50 | 3.438 | 0.531 | 6.00 | 160 | 22.00 |
| 5 | 5.56 | 4.310 | 0.625 | 7.50 | 160 | 33.00 |
| 6 | 6.62 | 5.182 | 0.719 | 9.00 | 160 | 62.00 |
| 8 | 8.62 | 6.808 | 0.906 | 12.00 | 160 | 122.00 |
| 10 | 10.75 | 8.500 | 1.125 | 15.00 | 160 | 270.00 |
| 12 | 12.75 | 10.126 | 1.312 | 18.00 | 160 | 460.00 |
| 14 | 14.00 | 11.188 | 1.406 | 21.00 | 160 | 563.00 |
| 16 | 16.00 | 12.812 | 1.594 | 24.00 | 160 | 825.00 |
| 18 | 18.00 | 14.438 | 1.781 | 27.00 | 160 | 1240.00 |
| 20 | 20.00 | 16.062 | 1.969 | 30.00 | 160 | 1510.00 |
| 24 | 24.00 | 19.312 | 2.344 | 36.00 | 160 | 1760.00 |
Schedule XXS
| Nom. Pipe Size | Outside Diameter O.D. | Inside Diameter I.D. | Wall Thickness T | Center to End C | Pipe Schedule Number | Approx. Weight in Pounds Lbs. |
|---|---|---|---|---|---|---|
| ½ | 0.84 | 0.252 | 0.294 | 1.50 | * | 0.30 |
| ¾ | 1.05 | 0.434 | 0.308 | 1.50 | * | 0.30 |
| 1 | 1.32 | 0.604 | 0.358 | 1.50 | * | 0.80 |
| 1¼ | 1.66 | 0.896 | 0.382 | 1.88 | * | 1.40 |
| 1½ | 1.90 | 1.100 | 0.400 | 2.25 | * | 2.00 |
| 2 | 2.38 | 1.508 | 0.436 | 3.00 | * | 3.90 |
| 2½ | 2.88 | 1.776 | 0.552 | 3.75 | * | 6.80 |
| 3 | 3.50 | 2.300 | 0.600 | 4.50 | * | 11.30 |
| 4 | 4.50 | 3.152 | 0.674 | 6.00 | * | 23.00 |
| 5 | 5.56 | 4.060 | 0.750 | 7.50 | * | 38.00 |
| 6 | 6.62 | 4.892 | 0.864 | 9.00 | * | 69.00 |
| 8 | 8.62 | 6.870 | 0.875 | 12.00 | * | 120.00 |
| 10 | 10.75 | 8.750 | 1.000 | 15.00 | 140 | 232.00 |
| 12 | 12.75 | 10.750 | 1.000 | 18.00 | 120 | 315.00 |
Materials We Supply
90° Long Radius Elbow to ASME B16.9 in the grades below. Tell us the service and we will confirm the right one.
| Material | Specification | Typical Service |
|---|---|---|
| Carbon Steel | ASTM A234 WPB / WPC | General process, steam, oil and gas gathering and utility lines |
| Low-Temp Carbon Steel | ASTM A420 WPL6 | Cold service to −50°F; LNG and northern pipeline work |
| Chrome-Moly Alloy | ASTM A234 WP11 / WP22 / WP91 | Elevated temperature; refinery heaters, power plant steam |
| Stainless Steel | ASTM A403 WP304/304L, WP316/316L | Corrosive service, chemical, food and beverage, water treatment |
| Duplex & Super Duplex | ASTM A815 UNS S31803 / S32750 | Chloride and seawater service, offshore, desalination |
Common Questions
What is the difference between a long radius and short radius elbow?
Centerline radius. A long radius elbow turns on a radius of 1.5 times the nominal pipe size; a short radius elbow turns on 1.0 times. Long radius is the default because the gentler sweep means lower pressure drop and less erosion. Short radius is the fallback when there is not enough room for the full turn.
What does the C dimension mean on an elbow?
C is the center-to-end distance: from the theoretical intersection of the two pipe centerlines to the welding end face. On a standard long radius 90° elbow it equals 1.5 × the nominal pipe size, so a 6" elbow has a 9" center-to-end.
What standard covers butt weld elbows?
ASME B16.9 covers dimensions and tolerances for factory-made wrought butt-welding fittings. Material is specified separately, most commonly ASTM A234 for carbon and alloy steel, or ASTM A403 for stainless.
