180° Short Radius Return Bend Dimensions
The short radius return bend reverses flow on a 1.0D centerline radius, folding the line back in the tightest space the standard allows. It is what you use when coil spacing will not accommodate the long radius pattern.
Tighter spacing, tighter tolerances.
The short radius pattern brings the two legs closer together, which is exactly what heater and exchanger coil pitch often demands. The trade is the same as with elbows: more turbulence through the turn, and more concentrated wear on the outside of the bend.
Match the pattern to the coil.
Coil pitch is fixed by the bundle or the firebox, so the return bend pattern is usually dictated rather than chosen. Confirm the V dimension against the design pitch before ordering. Long and short patterns are not interchangeable.
101 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 Center V | Back to Face W | Pipe Schedule Number | Approx. Weight in Pounds Lbs. |
|---|---|---|---|---|---|---|---|
| 1 | 1.32 | 1.049 | 0.133 | 2.00 | 1.62 | 40 | 0.50 |
| 1¼ | 1.66 | 1.380 | 0.140 | 2.50 | 2.06 | 40 | 0.80 |
| 1½ | 1.90 | 1.610 | 0.145 | 3.00 | 2.44 | 40 | 1.10 |
| 2 | 2.38 | 2.067 | 0.154 | 4.00 | 3.19 | 40 | 1.90 |
| 2½ | 2.88 | 2.469 | 0.203 | 5.00 | 3.94 | 40 | 4.00 |
| 3 | 3.50 | 3.068 | 0.216 | 6.00 | 4.75 | 40 | 6.00 |
| 3½ | 4.00 | 3.548 | 0.226 | 7.00 | 5.50 | 40 | 8.70 |
| 4 | 4.50 | 4.026 | 0.237 | 8.00 | 6.25 | 40 | 12.20 |
| 5 | 5.56 | 5.047 | 0.258 | 10.00 | 7.75 | 40 | 19.20 |
| 6 | 6.62 | 6.065 | 0.280 | 12.00 | 9.31 | 40 | 32.90 |
| 8 | 8.62 | 7.981 | 0.322 | 16.00 | 12.31 | 40 | 64.90 |
| 10 | 10.75 | 10.020 | 0.365 | 20.00 | 15.38 | 40 | 112.00 |
| 12 | 12.75 | 12.000 | 0.375 | 24.00 | 18.38 | * | 157.00 |
| 14 | 14.00 | 13.250 | 0.375 | 28.00 | 21.00 | 30 | 208.00 |
| 16 | 16.00 | 15.250 | 0.375 | 32.00 | 24.00 | 30 | 257.00 |
| 18 | 18.00 | 17.250 | 0.375 | 36.00 | 27.00 | * | 325.00 |
| 20 | 20.00 | 19.250 | 0.375 | 40.00 | 30.00 | 20 | 416.00 |
| 24 | 24.00 | 23.250 | 0.375 | 48.00 | 36.00 | 20 | 592.00 |
Schedule XS
| Nom. Pipe Size | Outside Diameter O.D. | Inside Diameter I.D. | Wall Thickness T | Center to Center V | Back to Face W | Pipe Schedule Number | Approx. Weight in Pounds Lbs. |
|---|---|---|---|---|---|---|---|
| 1 | 1.32 | 0.962 | 0.179 | 2.00 | 1.62 | 80 | 0.70 |
| 1¼ | 1.66 | 1.278 | 0.191 | 2.50 | 2.06 | 80 | 1.00 |
| 1½ | 1.90 | 1.500 | 0.200 | 3.00 | 2.44 | 80 | 1.50 |
| 2 | 2.38 | 1.939 | 0.218 | 4.00 | 3.19 | 80 | 2.90 |
| 2½ | 2.88 | 2.323 | 0.276 | 5.00 | 3.94 | 80 | 5.20 |
| 3 | 3.50 | 2.900 | 0.300 | 6.00 | 4.75 | 80 | 8.20 |
| 3½ | 4.00 | 3.364 | 0.318 | 7.00 | 5.50 | 80 | 11.70 |
| 4 | 4.50 | 3.826 | 0.337 | 8.00 | 6.25 | 80 | 16.40 |
| 5 | 5.56 | 4.813 | 0.375 | 10.00 | 7.75 | 80 | 27.70 |
| 6 | 6.62 | 5.761 | 0.432 | 12.00 | 9.31 | 80 | 45.70 |
| 8 | 8.62 | 7.625 | 0.500 | 16.00 | 12.31 | 80 | 96.30 |
| 10 | 10.75 | 9.750 | 0.500 | 20.00 | 15.38 | 60 | 143.00 |
| 12 | 12.75 | 11.750 | 0.500 | 24.00 | 18.38 | * | 212.00 |
| 14 | 14.00 | 13.000 | 0.500 | 28.00 | 21.00 | * | 271.00 |
| 16 | 16.00 | 15.000 | 0.500 | 32.00 | 24.00 | 40 | 339.00 |
| 18 | 18.00 | 17.000 | 0.500 | 36.00 | 27.00 | * | 425.00 |
| 20 | 20.00 | 19.000 | 0.500 | 40.00 | 30.00 | 30 | 555.00 |
| 24 | 24.00 | 23.000 | 0.500 | 48.00 | 36.00 | * | 778.00 |
Schedule 40
| Nom. Pipe Size | Outside Diameter O.D. | Inside Diameter I.D. | Wall Thickness T | Center to Center V | Back to Face W | Pipe Schedule Number | Approx. Weight in Pounds Lbs. |
|---|---|---|---|---|---|---|---|
| 1 | 1.32 | 1.054 | 0.133 | 2.00 | 1.62 | 40 | 0.50 |
| 1¼ | 1.66 | 1.380 | 0.140 | 2.50 | 2.06 | 40 | 0.80 |
| 1½ | 1.90 | 1.610 | 0.145 | 3.00 | 2.44 | 40 | 1.10 |
| 2 | 2.38 | 2.072 | 0.154 | 4.00 | 3.19 | 40 | 1.90 |
| 2½ | 2.88 | 2.474 | 0.203 | 5.00 | 3.94 | 40 | 4.00 |
| 3 | 3.50 | 3.068 | 0.216 | 6.00 | 4.75 | 40 | 6.00 |
| 3½ | 4.00 | 3.548 | 0.226 | 7.00 | 5.50 | 40 | 8.70 |
| 4 | 4.50 | 4.026 | 0.237 | 8.00 | 6.25 | 40 | 12.20 |
| 5 | 5.56 | 5.044 | 0.258 | 10.00 | 7.75 | 40 | 19.20 |
| 6 | 6.62 | 6.060 | 0.280 | 12.00 | 9.31 | 40 | 32.90 |
| 8 | 8.62 | 7.976 | 0.322 | 16.00 | 12.31 | 40 | 64.90 |
| 10 | 10.75 | 10.020 | 0.365 | 20.00 | 15.38 | 40 | 112.00 |
| 12 | 12.75 | 11.938 | 0.406 | 24.00 | 18.38 | 40 | 165.00 |
| 14 | 14.00 | 13.124 | 0.438 | 28.00 | 21.00 | 40 | 215.00 |
| 16 | 16.00 | 15.000 | 0.500 | 32.00 | 24.00 | 40 | 265.00 |
| 18 | 18.00 | 16.876 | 0.562 | 36.00 | 27.00 | 40 | 335.00 |
| 20 | 20.00 | 18.812 | 0.594 | 40.00 | 30.00 | 40 | 425.00 |
| 24 | 24.00 | 22.624 | 0.688 | 48.00 | 36.00 | 40 | 605.00 |
Schedule 80
| Nom. Pipe Size | Outside Diameter O.D. | Inside Diameter I.D. | Wall Thickness T | Center to Center V | Back to Face W | Pipe Schedule Number | Approx. Weight in Pounds Lbs. |
|---|---|---|---|---|---|---|---|
| 1 | 1.32 | 0.962 | 0.179 | 2.00 | 1.62 | 80 | 0.70 |
| 1¼ | 1.66 | 1.278 | 0.191 | 2.50 | 2.06 | 80 | 1.00 |
| 1½ | 1.90 | 1.500 | 0.200 | 3.00 | 2.44 | 80 | 1.50 |
| 2 | 2.38 | 1.944 | 0.218 | 4.00 | 3.19 | 80 | 2.90 |
| 2½ | 2.88 | 2.328 | 0.276 | 5.00 | 3.94 | 80 | 5.20 |
| 3 | 3.50 | 2.900 | 0.300 | 6.00 | 4.75 | 80 | 8.20 |
| 3½ | 4.00 | 3.364 | 0.318 | 7.00 | 5.50 | 80 | 11.70 |
| 4 | 4.50 | 3.826 | 0.337 | 8.00 | 6.25 | 80 | 16.40 |
| 5 | 5.56 | 4.810 | 0.375 | 10.00 | 7.75 | 80 | 27.70 |
| 6 | 6.62 | 5.756 | 0.432 | 12.00 | 9.31 | 80 | 45.70 |
| 8 | 8.62 | 7.620 | 0.500 | 16.00 | 12.31 | 80 | 96.30 |
| 10 | 10.75 | 9.562 | 0.594 | 20.00 | 15.38 | 80 | 160.00 |
| 12 | 12.75 | 11.374 | 0.688 | 24.00 | 18.38 | 80 | 225.00 |
| 14 | 14.00 | 12.500 | 0.750 | 28.00 | 21.00 | 80 | 280.00 |
| 16 | 16.00 | 14.312 | 0.844 | 32.00 | 24.00 | 80 | 350.00 |
| 18 | 18.00 | 16.124 | 0.938 | 36.00 | 27.00 | 80 | 435.00 |
| 20 | 20.00 | 17.938 | 1.031 | 40.00 | 30.00 | 80 | 570.00 |
| 24 | 24.00 | 21.562 | 1.219 | 48.00 | 36.00 | 80 | 790.00 |
Schedule 160
| Nom. Pipe Size | Outside Diameter O.D. | Inside Diameter I.D. | Wall Thickness T | Center to Center V | Back to Face W | Pipe Schedule Number | Approx. Weight in Pounds Lbs. |
|---|---|---|---|---|---|---|---|
| 1 | 1.32 | 0.820 | 0.250 | 2.00 | 1.62 | 160 | 0.85 |
| 1¼ | 1.66 | 1.160 | 0.250 | 2.50 | 2.06 | 160 | 1.21 |
| 1½ | 1.90 | 1.338 | 0.281 | 3.00 | 2.44 | 160 | 1.82 |
| 2 | 2.38 | 1.692 | 0.344 | 4.00 | 3.19 | 160 | 3.51 |
| 2½ | 2.88 | 2.130 | 0.375 | 5.00 | 3.94 | 160 | 6.29 |
| 3 | 3.50 | 2.624 | 0.438 | 6.00 | 4.75 | 160 | 9.92 |
| 4 | 4.50 | 3.438 | 0.531 | 8.00 | 6.25 | 160 | 19.84 |
| 5 | 5.56 | 4.310 | 0.625 | 10.00 | 7.75 | 160 | 33.52 |
| 6 | 6.62 | 5.182 | 0.719 | 12.00 | 9.31 | 160 | 55.30 |
| 8 | 8.62 | 6.808 | 0.906 | 16.00 | 12.31 | 160 | 116.52 |
| 10 | 10.75 | 8.500 | 1.125 | 20.00 | 15.38 | 160 | 173.03 |
| 12 | 12.75 | 10.126 | 1.312 | 24.00 | 18.38 | 160 | 256.52 |
| 14 | 14.00 | 11.188 | 1.406 | 28.00 | 21.00 | 160 | 327.91 |
| 16 | 16.00 | 12.812 | 1.594 | 32.00 | 24.00 | 160 | 410.19 |
| 18 | 18.00 | 14.438 | 1.781 | 36.00 | 27.00 | 160 | 514.25 |
| 20 | 20.00 | 16.062 | 1.969 | 40.00 | 30.00 | 160 | 671.55 |
| 24 | 24.00 | 19.312 | 2.344 | 48.00 | 36.00 | 160 | 941.38 |
Schedule XXS
| Nom. Pipe Size | Outside Diameter O.D. | Inside Diameter I.D. | Wall Thickness T | Center to Center V | Back to Face W | Pipe Schedule Number | Approx. Weight in Pounds Lbs. |
|---|---|---|---|---|---|---|---|
| 1 | 1.32 | 0.604 | 0.358 | 2.00 | 1.62 | * | 0.93 |
| 1¼ | 1.66 | 0.896 | 0.382 | 2.50 | 2.06 | * | 1.33 |
| 1½ | 1.90 | 1.100 | 0.400 | 3.00 | 2.44 | * | 2.00 |
| 2 | 2.38 | 1.508 | 0.436 | 4.00 | 3.19 | * | 3.90 |
| 2½ | 2.88 | 1.776 | 0.552 | 5.00 | 3.94 | * | 6.92 |
| 3 | 3.50 | 2.300 | 0.600 | 6.00 | 4.75 | * | 10.91 |
| 4 | 4.50 | 3.152 | 0.674 | 8.00 | 6.25 | * | 21.83 |
| 5 | 5.56 | 4.060 | 0.750 | 10.00 | 7.75 | * | 36.87 |
| 6 | 6.62 | 4.892 | 0.864 | 12.00 | 9.31 | * | 60.83 |
| 8 | 8.62 | 6.870 | 0.875 | 16.00 | 12.31 | * | 128.18 |
| 10 | 10.75 | 8.750 | 1.000 | 20.00 | 15.38 | 140 | 190.33 |
| 12 | 12.75 | 10.750 | 1.000 | 24.00 | 18.38 | 120 | 282.17 |
Materials We Supply
180° Short Radius Return Bend 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 and short radius return bend?
Centerline radius, and therefore the spacing between the two legs. Long radius turns on 1.5 times the nominal diameter, short radius on 1.0. The short pattern packs the legs closer together for tight coil pitch, at the cost of more turbulence through the turn.
How do I know which return bend pattern my coil needs?
The coil pitch usually fixes it. Compare the required centerline-to-centerline spacing with the V dimension in the tables above; the pattern whose V matches your design pitch is the one to order.
Are return bends made in the same materials as elbows?
Yes. The same ASTM A234, A403, A420 and alloy grades apply. Tell us the size, schedule, and grade and we will confirm availability.
