90° Reducing Elbow Dimensions
A reducing elbow turns dat line 90° and changes the size right in the same fitting. It takes the place of an elbow, a reducer, and the weld between 'em, savin' y'all a joint, cuttin' down on length, and gettin' rid of a spot where a leak might spring up in the spool.
One fittin' instead of three parts.
Every weld y'all delete is a weld you don't gotta fit, inspect, or eventually chase down for a leak. In tight pump suction and discharge work, where the size change has gotta happen right at the turn, dat reducin' elbow is often the only thing dat fits at all, I tell you what.
Readin' the two-size table.
Sizes are listed large × small, so a "6 × 4" is a 6" inlet turnin' to a 4" outlet. The table carries outside diameter, inside diameter, and wall thickness for both ends, so be sure to check 'em both against your matin' pipe before y'all put an order in.
How To Read Dese Dimensions
ASME B16.9 covers the 90 degree reducin' elbow, dimensionin' the large and the small end separately. Dem source tables carry the note "for reference only", so y'all better confirm the center-to-end and both wall thicknesses with us against your size and schedule before that spool gets cut, I reckon.
- O.D.
- Outside diameterOutside diameter at the weldin' end, matchin' up perfect with the pipe it welds to.
- I.D.
- Inside diameterBore right through the fitting, set by dat wall thickness.
- T
- Wall thicknessNominal wall at the weldin' end, matched to the pipe schedule.
- C
- Center to endFrom the intersection of the centerlines to the welding face. Each end carries its own O.D., I.D. and T, listed side by side right there in the table.
132 sizes across 8 schedules · dimensions in inches, weights in pounds · ASME B16.9
Schedule STD
| Nom. Large × Small | O.D. | LARGE DIAMETER I.D. | T | O.D. | SMALL DIAMETER I.D. | T | Center to End C | Pipe Sched. No. | Approx. Wt. Lbs. |
|---|---|---|---|---|---|---|---|---|---|
| 2 × 1½ | 2.38 | 2.072 | 0.154 | 1.90 | 1.610 | 0.145 | 3.00 | 40 | 1.40 |
| 2 × 1¼ | 2.38 | 2.072 | 0.154 | 1.66 | 1.380 | 0.140 | 3.00 | 40 | 1.30 |
| 2 × 1 | 2.38 | 2.072 | 0.154 | 1.32 | 1.054 | 0.133 | 3.00 | 40 | 1.20 |
| 2½ × 2 | 2.88 | 2.474 | 0.203 | 2.38 | 2.072 | 0.154 | 3.75 | 40 | 2.80 |
| 2½ × 1½ | 2.88 | 2.474 | 0.203 | 1.90 | 1.610 | 0.145 | 3.75 | 40 | 2.60 |
| 2½ × 1¼ | 2.88 | 2.474 | 0.203 | 1.66 | 1.380 | 0.140 | 3.75 | 40 | 2.50 |
| 3 × 2½ | 3.50 | 3.068 | 0.216 | 2.88 | 2.474 | 0.203 | 4.50 | 40 | 4.20 |
| 3 × 2 | 3.50 | 3.068 | 0.216 | 2.38 | 2.072 | 0.154 | 4.50 | 40 | 3.60 |
| 3 × 1½ | 3.50 | 3.068 | 0.216 | 1.90 | 1.610 | 0.145 | 4.50 | 40 | 3.30 |
| 3½ × 3 | 4.00 | 3.548 | 0.226 | 3.50 | 3.068 | 0.216 | 5.25 | 40 | 6.00 |
| 3½ × 2½ | 4.00 | 3.548 | 0.226 | 2.88 | 2.474 | 0.203 | 5.25 | 40 | 5.50 |
| 3½ × 2 | 4.00 | 3.548 | 0.226 | 2.38 | 2.072 | 0.154 | 5.25 | 40 | 4.50 |
| 4 × 3½ | 4.50 | 4.026 | 0.237 | 4.00 | 3.548 | 0.226 | 6.00 | 40 | 8.40 |
| 4 × 3 | 4.50 | 4.026 | 0.237 | 3.50 | 3.068 | 0.216 | 6.00 | 40 | 7.70 |
| 4 × 2½ | 4.50 | 4.026 | 0.237 | 2.88 | 2.474 | 0.203 | 6.00 | 40 | 6.80 |
| 4 × 2 | 4.50 | 4.026 | 0.237 | 2.38 | 2.072 | 0.154 | 6.00 | 40 | 6.00 |
| 5 × 4 | 5.56 | 5.044 | 0.258 | 4.50 | 4.026 | 0.237 | 7.50 | 40 | 13.40 |
Schedule STD (cont.)
| Nom. Large × Small | O.D. | LARGE DIAMETER I.D. | T | O.D. | SMALL DIAMETER I.D. | T | Center to End C | Pipe Sched. No. | Approx. Wt. Lbs. |
|---|---|---|---|---|---|---|---|---|---|
| 5 × 3½ | 5.56 | 5.044 | 0.258 | 4.00 | 3.548 | 0.226 | 7.50 | 40 | 12.60 |
| 5 × 3 | 5.56 | 5.044 | 0.258 | 3.50 | 3.068 | 0.216 | 7.50 | 40 | 11.80 |
| 5 × 2½ | 5.56 | 5.044 | 0.258 | 2.88 | 2.474 | 0.203 | 7.50 | 40 | 10.70 |
| 6 × 5 | 6.62 | 6.060 | 0.280 | 5.56 | 5.044 | 0.258 | 9.00 | 40 | 21.00 |
| 6 × 4 | 6.62 | 6.060 | 0.280 | 4.50 | 4.026 | 0.237 | 9.00 | 40 | 18.90 |
| 6 × 3½ | 6.62 | 6.060 | 0.280 | 4.00 | 3.548 | 0.226 | 9.00 | 40 | 17.80 |
| 6 × 3 | 6.62 | 6.060 | 0.280 | 3.50 | 3.068 | 0.216 | 9.00 | 40 | 16.80 |
| 8 × 6 | 8.62 | 7.976 | 0.322 | 6.62 | 6.060 | 0.280 | 12.00 | 40 | 39.70 |
| 8 × 5 | 8.62 | 7.976 | 0.322 | 5.56 | 5.044 | 0.258 | 12.00 | 40 | 36.20 |
| 8 × 4 | 8.62 | 7.976 | 0.322 | 4.50 | 4.026 | 0.237 | 12.00 | 40 | 33.10 |
| 10 × 8 | 10.75 | 10.020 | 0.365 | 8.62 | 7.976 | 0.322 | 15.00 | 40 | 73.00 |
| 10 × 6 | 10.75 | 10.020 | 0.365 | 6.62 | 6.060 | 0.280 | 15.00 | 40 | 63.20 |
| 10 × 5 | 10.75 | 10.020 | 0.365 | 5.56 | 5.044 | 0.258 | 15.00 | 40 | 58.50 |
| 12 × 10 | 12.75 | 12.000 | 0.375 | 10.75 | 10.020 | 0.365 | 18.00 | * | 113.00 |
| 12 × 8 | 12.75 | 12.000 | 0.375 | 8.62 | 7.976 | 0.322 | 18.00 | * | 98.40 |
| 12 × 6 | 12.75 | 12.000 | 0.375 | 6.62 | 6.060 | 0.280 | 18.00 | * | 86.50 |
Schedule XS
| Nom. Large × Small | O.D. | LARGE DIAMETER I.D. | T | O.D. | SMALL DIAMETER I.D. | T | Center to End C | Pipe Sched. No. | Approx. Wt. Lbs. |
|---|---|---|---|---|---|---|---|---|---|
| 2 × 1½ | 2.38 | 1.944 | 0.218 | 1.90 | 1.500 | 0.200 | 3.00 | 80 | 1.90 |
| 2 × 1¼ | 2.38 | 1.944 | 0.218 | 1.66 | 1.278 | 0.191 | 3.00 | 80 | 1.80 |
| 2 × 1 | 2.38 | 1.944 | 0.218 | 1.32 | 0.962 | 0.179 | 3.00 | 80 | 1.70 |
| 2½ × 2 | 2.88 | 2.328 | 0.276 | 2.38 | 1.944 | 0.218 | 3.75 | 80 | 3.40 |
| 2½ × 1½ | 2.88 | 2.328 | 0.276 | 1.90 | 1.500 | 0.200 | 3.75 | 80 | 3.00 |
| 2½ × 1¼ | 2.88 | 2.328 | 0.276 | 1.66 | 1.278 | 0.191 | 3.75 | 80 | 2.90 |
| 3 × 2½ | 3.50 | 2.900 | 0.300 | 2.88 | 2.328 | 0.276 | 4.50 | 80 | 5.70 |
| 3 × 2 | 3.50 | 2.900 | 0.300 | 2.38 | 1.944 | 0.218 | 4.50 | 80 | 4.90 |
| 3 × 1½ | 3.50 | 2.900 | 0.300 | 1.90 | 1.500 | 0.200 | 4.50 | 80 | 4.50 |
| 3½ × 3 | 4.00 | 3.364 | 0.318 | 3.50 | 2.900 | 0.300 | 5.25 | 80 | 8.20 |
| 3½ × 2½ | 4.00 | 3.364 | 0.318 | 2.88 | 2.328 | 0.276 | 5.25 | 80 | 7.30 |
| 3½ × 2 | 4.00 | 3.364 | 0.318 | 2.38 | 1.944 | 0.218 | 5.25 | 80 | 6.40 |
| 4 × 3½ | 4.50 | 3.826 | 0.337 | 4.00 | 3.364 | 0.318 | 6.00 | 80 | 11.40 |
| 4 × 3 | 4.50 | 3.826 | 0.337 | 3.50 | 2.900 | 0.300 | 6.00 | 80 | 10.50 |
| 4 × 2½ | 4.50 | 3.826 | 0.337 | 2.88 | 2.328 | 0.276 | 6.00 | 80 | 9.40 |
| 4 × 2 | 4.50 | 3.826 | 0.337 | 2.38 | 1.944 | 0.218 | 6.00 | 80 | 8.40 |
| 5 × 4 | 5.56 | 4.810 | 0.375 | 4.50 | 3.826 | 0.337 | 7.50 | 80 | 18.80 |
Schedule XS (cont.)
| Nom. Large × Small | O.D. | LARGE DIAMETER I.D. | T | O.D. | SMALL DIAMETER I.D. | T | Center to End C | Pipe Sched. No. | Approx. Wt. Lbs. |
|---|---|---|---|---|---|---|---|---|---|
| 5 × 3½ | 5.56 | 4.810 | 0.375 | 4.00 | 3.364 | 0.318 | 7.50 | 80 | 17.40 |
| 5 × 3 | 5.56 | 4.810 | 0.375 | 3.50 | 2.900 | 0.300 | 7.50 | 80 | 16.50 |
| 5 × 2½ | 5.56 | 4.810 | 0.375 | 2.88 | 2.328 | 0.276 | 7.50 | 80 | 15.10 |
| 6 × 5 | 6.62 | 5.756 | 0.432 | 5.56 | 4.810 | 0.375 | 9.00 | 80 | 31.40 |
| 6 × 4 | 6.62 | 5.756 | 0.432 | 4.50 | 3.826 | 0.337 | 9.00 | 80 | 27.90 |
| 6 × 3½ | 6.62 | 5.756 | 0.432 | 4.00 | 3.364 | 0.318 | 9.00 | 80 | 26.30 |
| 6 × 3 | 6.62 | 5.756 | 0.432 | 3.50 | 2.900 | 0.300 | 9.00 | 80 | 24.90 |
| 8 × 6 | 8.62 | 7.620 | 0.500 | 6.62 | 5.756 | 0.432 | 12.00 | 80 | 60.80 |
| 8 × 5 | 8.62 | 7.620 | 0.500 | 5.56 | 4.810 | 0.375 | 12.00 | 80 | 54.30 |
| 8 × 4 | 8.62 | 7.620 | 0.500 | 4.50 | 3.826 | 0.337 | 12.00 | 80 | 49.50 |
| 10 × 8 | 10.75 | 9.750 | 0.500 | 8.62 | 7.620 | 0.500 | 15.00 | * | 102.00 |
| 10 × 6 | 10.75 | 9.750 | 0.500 | 6.62 | 5.756 | 0.432 | 15.00 | * | 86.50 |
| 10 × 5 | 10.75 | 9.750 | 0.500 | 5.56 | 4.810 | 0.375 | 15.00 | * | 78.50 |
| 12 × 10 | 12.75 | 11.750 | 0.500 | 10.75 | 9.750 | 0.500 | 18.00 | * | 148.00 |
| 12 × 8 | 12.75 | 11.750 | 0.500 | 8.62 | 7.620 | 0.500 | 18.00 | * | 132.00 |
| 12 × 6 | 12.75 | 11.750 | 0.500 | 6.62 | 5.756 | 0.432 | 18.00 | * | 114.00 |
Schedule 40
| Nom. Large × Small | O.D. | LARGE DIAMETER I.D. | T | O.D. | SMALL DIAMETER I.D. | T | Center to End C | Pipe Sched. No. | Approx. Wt. Lbs. |
|---|---|---|---|---|---|---|---|---|---|
| 2 × 1½ | 2.38 | 2.072 | 0.154 | 1.90 | 1.610 | 0.145 | 3.00 | 40 | 1.40 |
| 2 × 1¼ | 2.38 | 2.072 | 0.154 | 1.66 | 1.380 | 0.140 | 3.00 | 40 | 1.30 |
| 2 × 1 | 2.38 | 2.072 | 0.154 | 1.32 | 1.054 | 0.133 | 3.00 | 40 | 1.20 |
| 2½ × 2 | 2.88 | 2.474 | 0.203 | 2.38 | 2.072 | 0.154 | 3.75 | 40 | 2.80 |
| 2½ × 1½ | 2.88 | 2.474 | 0.203 | 1.90 | 1.610 | 0.145 | 3.75 | 40 | 2.60 |
| 2½ × 1¼ | 2.88 | 2.474 | 0.203 | 1.66 | 1.380 | 0.140 | 3.75 | 40 | 2.50 |
| 3 × 2½ | 3.50 | 3.068 | 0.216 | 2.88 | 2.474 | 0.203 | 4.50 | 40 | 4.20 |
| 3 × 2 | 3.50 | 3.068 | 0.216 | 2.38 | 2.072 | 0.154 | 4.50 | 40 | 3.60 |
| 3 × 1½ | 3.50 | 3.068 | 0.216 | 1.90 | 1.610 | 0.145 | 4.50 | 40 | 3.30 |
| 3½ × 3 | 4.00 | 3.548 | 0.226 | 3.50 | 3.068 | 0.216 | 5.25 | 40 | 6.00 |
| 3½ × 2½ | 4.00 | 3.548 | 0.226 | 2.88 | 2.474 | 0.203 | 5.25 | 40 | 5.50 |
| 3½ × 2 | 4.00 | 3.548 | 0.226 | 2.38 | 2.072 | 0.154 | 5.25 | 40 | 4.50 |
| 4 × 3½ | 4.50 | 4.026 | 0.237 | 4.00 | 3.548 | 0.226 | 6.00 | 40 | 8.40 |
| 4 × 3 | 4.50 | 4.026 | 0.237 | 3.50 | 3.068 | 0.216 | 6.00 | 40 | 7.70 |
| 4 × 2½ | 4.50 | 4.026 | 0.237 | 2.88 | 2.474 | 0.203 | 6.00 | 40 | 6.80 |
| 4 × 2 | 4.50 | 4.026 | 0.237 | 2.38 | 2.072 | 0.154 | 6.00 | 40 | 6.00 |
| 5 × 4 | 5.56 | 5.044 | 0.258 | 4.50 | 4.026 | 0.237 | 7.50 | 40 | 13.40 |
Schedule 40 (cont.)
| Nom. Large × Small | O.D. | LARGE DIAMETER I.D. | T | O.D. | SMALL DIAMETER I.D. | T | Center to End C | Pipe Sched. No. | Approx. Wt. Lbs. |
|---|---|---|---|---|---|---|---|---|---|
| 5 × 3½ | 5.56 | 5.044 | 0.258 | 4.00 | 3.548 | 0.226 | 7.50 | 40 | 12.60 |
| 5 × 3 | 5.56 | 5.044 | 0.258 | 3.50 | 3.068 | 0.216 | 7.50 | 40 | 11.80 |
| 5 × 2½ | 5.56 | 5.044 | 0.258 | 2.88 | 2.474 | 0.203 | 7.50 | 40 | 10.70 |
| 6 × 5 | 6.62 | 6.060 | 0.280 | 5.56 | 5.044 | 0.258 | 9.00 | 40 | 21.00 |
| 6 × 4 | 6.62 | 6.060 | 0.280 | 4.50 | 4.026 | 0.237 | 9.00 | 40 | 18.90 |
| 6 × 3½ | 6.62 | 6.060 | 0.280 | 4.00 | 3.548 | 0.226 | 9.00 | 40 | 17.80 |
| 6 × 3 | 6.62 | 6.060 | 0.280 | 3.50 | 3.068 | 0.216 | 9.00 | 40 | 16.80 |
| 8 × 6 | 8.62 | 7.976 | 0.322 | 6.62 | 6.060 | 0.280 | 12.00 | 40 | 39.70 |
| 8 × 5 | 8.62 | 7.976 | 0.322 | 5.56 | 5.044 | 0.258 | 12.00 | 40 | 36.20 |
| 8 × 4 | 8.62 | 7.976 | 0.322 | 4.50 | 4.026 | 0.237 | 12.00 | 40 | 33.10 |
| 10 × 8 | 10.75 | 10.020 | 0.365 | 8.62 | 7.976 | 0.322 | 15.00 | 40 | 73.00 |
| 10 × 6 | 10.75 | 10.020 | 0.365 | 6.62 | 6.060 | 0.280 | 15.00 | 40 | 63.20 |
| 10 × 5 | 10.75 | 10.020 | 0.365 | 5.56 | 5.044 | 0.258 | 15.00 | 40 | 58.50 |
| 12 × 10 | 12.75 | 11.938 | 0.406 | 10.75 | 10.020 | 0.365 | 18.00 | 40 | 115.00 |
| 12 × 8 | 12.75 | 11.938 | 0.406 | 8.62 | 7.976 | 0.322 | 18.00 | 40 | 100.00 |
| 12 × 6 | 12.75 | 11.938 | 0.406 | 6.62 | 6.060 | 0.280 | 18.00 | 40 | 90.00 |
Schedule 80
| Nom. Large × Small | O.D. | LARGE DIAMETER I.D. | T | O.D. | SMALL DIAMETER I.D. | T | Center to End C | Pipe Sched. No. | Approx. Wt. Lbs. |
|---|---|---|---|---|---|---|---|---|---|
| 2 × 1½ | 2.38 | 1.944 | 0.218 | 1.90 | 1.500 | 0.200 | 3.00 | 80 | 1.90 |
| 2 × 1¼ | 2.38 | 1.944 | 0.218 | 1.66 | 1.278 | 0.191 | 3.00 | 80 | 1.80 |
| 2 × 1 | 2.38 | 1.944 | 0.218 | 1.32 | 0.962 | 0.179 | 3.00 | 80 | 1.70 |
| 2½ × 2 | 2.88 | 2.328 | 0.276 | 2.38 | 1.944 | 0.218 | 3.75 | 80 | 3.40 |
| 2½ × 1½ | 2.88 | 2.328 | 0.276 | 1.90 | 1.500 | 0.200 | 3.75 | 80 | 3.00 |
| 2½ × 1¼ | 2.88 | 2.328 | 0.276 | 1.66 | 1.278 | 0.191 | 3.75 | 80 | 2.90 |
| 3 × 2½ | 3.50 | 2.900 | 0.300 | 2.88 | 2.328 | 0.276 | 4.50 | 80 | 5.70 |
| 3 × 2 | 3.50 | 2.900 | 0.300 | 2.38 | 1.944 | 0.218 | 4.50 | 80 | 4.90 |
| 3 × 1½ | 3.50 | 2.900 | 0.300 | 1.90 | 1.500 | 0.200 | 4.50 | 80 | 4.50 |
| 3½ × 3 | 4.00 | 3.364 | 0.318 | 3.50 | 2.900 | 0.300 | 5.25 | 80 | 8.20 |
| 3½ × 2½ | 4.00 | 3.364 | 0.318 | 2.88 | 2.328 | 0.276 | 5.25 | 80 | 7.30 |
| 3½ × 2 | 4.00 | 3.364 | 0.318 | 2.38 | 1.944 | 0.218 | 5.25 | 80 | 6.40 |
| 4 × 3½ | 4.50 | 3.826 | 0.337 | 4.00 | 3.364 | 0.318 | 6.00 | 80 | 11.40 |
| 4 × 3 | 4.50 | 3.826 | 0.337 | 3.50 | 2.900 | 0.300 | 6.00 | 80 | 10.50 |
| 4 × 2½ | 4.50 | 3.826 | 0.337 | 2.88 | 2.328 | 0.276 | 6.00 | 80 | 9.40 |
| 4 × 2 | 4.50 | 3.826 | 0.337 | 2.38 | 1.944 | 0.218 | 6.00 | 80 | 8.40 |
| 5 × 4 | 5.56 | 4.810 | 0.375 | 4.50 | 3.826 | 0.337 | 7.50 | 80 | 18.80 |
Schedule 80 (cont.)
| Nom. Large × Small | O.D. | LARGE DIAMETER I.D. | T | O.D. | SMALL DIAMETER I.D. | T | Center to End C | Pipe Sched. No. | Approx. Wt. Lbs. |
|---|---|---|---|---|---|---|---|---|---|
| 5 × 3½ | 5.56 | 4.810 | 0.375 | 4.00 | 3.364 | 0.318 | 7.50 | 80 | 17.40 |
| 5 × 3 | 5.56 | 4.810 | 0.375 | 3.50 | 2.900 | 0.300 | 7.50 | 80 | 16.50 |
| 5 × 2½ | 5.56 | 4.810 | 0.375 | 2.88 | 2.328 | 0.276 | 7.50 | 80 | 15.10 |
| 6 × 5 | 6.62 | 5.756 | 0.432 | 5.56 | 4.810 | 0.375 | 9.00 | 80 | 31.40 |
| 6 × 4 | 6.62 | 5.756 | 0.432 | 4.50 | 3.826 | 0.337 | 9.00 | 80 | 27.90 |
| 6 × 3½ | 6.62 | 5.756 | 0.432 | 4.00 | 3.364 | 0.318 | 9.00 | 80 | 26.30 |
| 6 × 3 | 6.62 | 5.756 | 0.432 | 3.50 | 2.900 | 0.300 | 9.00 | 80 | 24.90 |
| 8 × 6 | 8.62 | 7.620 | 0.500 | 6.62 | 5.756 | 0.432 | 12.00 | 80 | 60.80 |
| 8 × 5 | 8.62 | 7.620 | 0.500 | 5.56 | 4.810 | 0.375 | 12.00 | 80 | 54.30 |
| 8 × 4 | 8.62 | 7.620 | 0.500 | 4.50 | 3.826 | 0.337 | 12.00 | 80 | 49.50 |
| 10 × 8 | 10.75 | 9.562 | 0.594 | 8.62 | 7.620 | 0.500 | 15.00 | 80 | 105.00 |
| 10 × 6 | 10.75 | 9.562 | 0.594 | 6.62 | 5.756 | 0.432 | 15.00 | 80 | 90.00 |
| 10 × 5 | 10.75 | 9.562 | 0.594 | 5.56 | 4.810 | 0.375 | 15.00 | 80 | 80.00 |
| 12 × 10 | 12.75 | 11.374 | 0.688 | 10.75 | 9.562 | 0.594 | 18.00 | 80 | 155.00 |
| 12 × 8 | 12.75 | 11.374 | 0.688 | 8.62 | 7.620 | 0.500 | 18.00 | 80 | 135.00 |
| 12 × 6 | 12.75 | 11.374 | 0.688 | 6.62 | 5.756 | 0.432 | 18.00 | 80 | 120.00 |
Materials We Supply
90° Reducing Elbow to ASME B16.9 in the grades below. Tell us the service and we'll confirm the right one for y'all.
| 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 |
Questions Folks Ask Us
What's a reducing elbow used for?
Turnin' the line 90° and changin' pipe size in a single fittin'. It removes the separate reducer and the weld between the two parts, which shortens the spool and gets rid of a joint.
How are reducing elbow sizes written?
Large end first, then small: a 6 × 4 reducin' elbow has a 6" inlet and a 4" outlet. Both ends got their own outside diameter, inside diameter, and wall thickness, all of which are sittin' right there in the table above.
Can I use a reducin' elbow on pump suction?
It's mighty common, but on horizontal pump suction you gotta watch for air pockets the same way you would with a concentric reducer. Where the line has to stay free of trapped vapour, an eccentric reducer plus a standard elbow might be the better arrangement, I reckon.
