An elbow is a pipe fitting installed between two lengths of pipe or tubing to allow a change of direction, usually a 90° or 45° angle, though 22.5° elbows are also made.
The ends may be machined for butt welding, threaded (usually female), or socketed, etc. When the two ends differ in size, the fitting is called a reducing elbow or reducer elbow.
- Pressure: SCH5 to SCH160
- Size range: 1/2 to 56 inches (DN 15 to DN 1,400mm), 22.5 Deg, 45 Deg, 90 Deg, 180 Deg
- Manufacturing standards: ANSI, ISO, JIS and DIN
- Process: butt welding, seamless, threaded , or socketed
Elbows are split into two groups which define the distance over which they change direction; the center line of one end to the opposite face. This is known as the "center to face" distance and is equivalent to the radius through which the elbow is bent.
Here below, for example, you will find the center to face distance of NPS 2 elbows (the A distance on the image)
- 90°-LR : = 1½ x 2(NPS) x 25.4 A=76.2 mm
- 180°-LR : = 2 times the 90° LR elbow A=152.4 mm
- 90°-SR : = 2(NPS) x 25.4 A=50.8 mm
- 180°-SR : = 2 times the 90° SR elbow A=101.6 mm
The center to face distance for a "long" radius elbow, abbreviated LR always is "1½ x Nominal Pipe Size (NPS) (1½D)", while the center to face distance for a "short" radius elbow, abbreviated SR even is to nominal pipe size.
3D elbows as an example, are calculated with:
3(D) x 2(NPS) x 25.4
- 90 Degree Elbow – where change in direction required is 90°
- 45 Degree Elbow – where change in direction required is 45°
- L/R - Long radius, S/R - Short radius
Nominal pipe size | Outside Diameter at Bevel | Center to End | Center to Center | Back to Faces | ||||||
45° Elbows | 90°Elbows | 180°Return | ||||||||
H | F | P | K | |||||||
DN | INCH | Series A | Series B | LR | LR | SR | LR | SR | LR | SR |
15 | 1/2 | 21.3 | 18 | 16 | 38 | - | 76 | - | 48 | - |
20 | 3/4 | 26.9 | 25 | 16 | 38 | - | 76 | - | 51 | - |
25 | 1 | 33.7 | 32 | 16 | 38 | 25 | 76 | 51 | 56 | 41 |
32 | 11/4 | 42.4 | 38 | 20 | 48 | 32 | 95 | 64 | 70 | 52 |
40 | 11/2 | 48.3 | 45 | 24 | 57 | 38 | 114 | 76 | 83 | 62 |
50 | 2 | 60.3 | 57 | 32 | 76 | 51 | 152 | 102 | 106 | 81 |
65 | 21/2 | 76.1(73) | 76 | 40 | 95 | 64 | 191 | 127 | 132 | 100 |
80 | 3 | 88.9 | 89 | 47 | 114 | 76 | 229 | 152 | 159 | 121 |
90 | 31/2 | 101.6 | - | 55 | 133 | 89 | 267 | 178 | 184 | 140 |
100 | 4 | 114.3 | 108 | 63 | 152 | 102 | 305 | 203 | 210 | 159 |
125 | 5 | 139.7 | 133 | 79 | 190 | 127 | 381 | 254 | 262 | 197 |
150 | 6 | 168.3 | 159 | 95 | 229 | 152 | 457 | 305 | 313 | 237 |
200 | 8 | 219.1 | 219 | 126 | 305 | 203 | 610 | 406 | 414 | 313 |
250 | 10 | 273.0 | 273 | 158 | 381 | 254 | 762 | 508 | 518 | 391 |
300 | 12 | 323.9 | 325 | 189 | 457 | 305 | 914 | 610 | 619 | 467 |
350 | 14 | 355.6 | 377 | 221 | 533 | 356 | 1067 | 711 | 711 | 533 |
400 | 16 | 406.4 | 426 | 253 | 610 | 406 | 1219 | 813 | 813 | 610 |
450 | 18 | 457.2 | 478 | 284 | 686 | 457 | 1372 | 914 | 914 | 686 |
500 | 20 | 508.0 | 529 | 316 | 762 | 508 | 1524 | 1016 | 1016 | 762 |
550 | 22 | 559 | - | 347 | 838 | 559 |
| |||
600 | 24 | 610 | 630 | 379 | 914 | 610 | ||||
650 | 26 | 660 | - | 410 | 991 | 660 | ||||
700 | 28 | 711 | 720 | 442 | 1067 | 711 | ||||
750 | 30 | 762 | - | 473 | 1143 | 762 | ||||
800 | 32 | 813 | 820 | 505 | 1219 | 813 | ||||
850 | 34 | 864 | - | 537 | 1295 | 864 | ||||
900 | 36 | 914 | 920 | 568 | 1372 | 914 | ||||
950 | 38 | 965 | - | 600 | 1448 | 965 | ||||
1000 | 40 | 1016 | 1020 | 631 | 1524 | 1016 | ||||
1050 | 42 | 1067 | - | 663 | 1600 | 1067 | ||||
1100 | 44 | 1118 | 1120 | 694 | 1676 | 1118 | ||||
1150 | 46 | 1168 | - | 726 | 1753 | 1168 | ||||
1200 | 48 | 1220 | 1220 | 758 | 1829 | 1219 |
Weight of elbows
NPS inches | ELBOWS LR 90° | ELBOWS SR 90° | ||||||
Sch. 5S | Sch. 10S | Sch. 40S | Sch. 80S | Sch. 5S | Sch. 10S | Sch. 40S | Sch. 80S | |
1/2 | 0.05 | 0.06 | 0.08 | 0.10 | 0.03 | 0.04 | 0.05 | 0.07 |
3/4 | 0.06 | 0.07 | 0.09 | 0.11 | 0.04 | 0.05 | 0.06 | 0.07 |
1 | 0.09 | 0.15 | 0.18 | 0.20 | 0.06 | 0.10 | 0.12 | 0.13 |
1 1/4 | 0.13 | 0.20 | 0.25 | 0.35 | 0.09 | 0.13 | 0.17 | 0.12 |
1 1/2 | 0.18 | 0.30 | 0.40 | 0.50 | 0.12 | 0.20 | 0.27 | 0.33 |
2 | 0.30 | 0.50 | 0.70 | 0.90 | 0.20 | 0.33 | 0.47 | 0.60 |
2 1/2 | 0.60 | 0.85 | 1.35 | 1.80 | 0.40 | 0.60 | 0.90 | 1.20 |
3 | 0.90 | 1.30 | 2.00 | 2.90 | 0.60 | 0.90 | 1.35 | 1.90 |
4 | 1.40 | 2.00 | 4.00 | 5.90 | 0.90 | 1.35 | 2.65 | 3.90 |
5 | 2.90 | 3.60 | 6.50 | 9.70 | 1.95 | 2.40 | 4.35 | 6.50 |
6 | 4.00 | 5.00 | 10.5 | 16.0 | 2.70 | 3.35 | 7.00 | 10.5 |
8 | 7.40 | 10.0 | 21.5 | 33.5 | 4.90 | 6.70 | 14.5 | 22.5 |
10 | 13.6 | 16.8 | 38.5 | 52.5 | 9.10 | 11.2 | 25.6 | 35.0 |
12 | 23.4 | 27.0 | 59.0 | 79.0 | 15.6 | 18.0 | 39.5 | 53.0 |
14 | 29.0 | 35.0 | 70.0 | 94.0 | 19.3 | 23.5 | 47.0 | 63.0 |
16 | 41.3 | 47.0 | 95.0 | 125 | 27.5 | 31.5 | 63.5 | 84.0 |
18 | 51.8 | 59.0 | 120 | 158 | 34.5 | 39.5 | 80.0 | 105 |
20 | 73.0 | 85.0 | 146 | 194 | 49.0 | 57.0 | 98.0 | 129 |
24 | 122 | 140 | 210 | 282 | 82.0 | 94.0 | 140 | 188 |
Approximate weights in kg, density 8 kg/dm3 |
Angularity Tolerances
ND | Max off angle | Max off plane |
Q | P | |
1/2 a 4 | 1 | 2 |
5 a 8 | 2 | 4 |
10 a 12 | 3 | 5 |
14 a 16 | 3 | 7 |
18 a 24 | 4 | 10 |
26 a 30 | 5 | 10 |
32 a 42 | 5 | 13 |
44 a 48 | 5 | 20 |
Key Specifications/Special Features and Materials::
the material is selected accoding to the application use such as high temperature use,sanitary fitting,regular industrial use etc.- Carbon steel: ASTM A234 WPB, WPC, ASTM A420 WPL1, WPL3, WPL6, WPHY-42/46/52/56/60/65/70
- Stainless steel: ASTM A403 WP304/304L, WP316/316/L, WP321, WP347 and WPS31254
- Alloy steel: ASTM A234 WP1/WP12/WP11/WP22/WP5/WP7/WP9/WP91
- Abrasion resistant material:Ceramic lined, Ceramic tile lined , Bi-metal clad pipe,
- Manufacturing standards: ANSI, ISO, JIS and DIN.
Application of pipe elbows:
Petroleum, chemical, power, gas, metallurgy, shipbuilding, construction, etc.
Wall Thickness of Elbows
The weakest point on an elbow is the inside radius. ASME B16.9 only standardizes the center to face dimensions and some "squareness" dimensional tolerances. The wall thickness at the weld line location even is standardized, but not through the rest of an elbow. The standard states that the minimum tolerance will be within 12.5% of the minimum ordered wall thickness of the pipe. A maximum tolerance is specified only at the ends of the fitting.