Stainless Steel 304 Long Radius Elbow is one of the most critical components used for changing flow direction in piping systems, offering reduced pressure drop and flow turbulence.
This article is an overview of the dimensional specifications for Stainless Steel 304 LR Elbows, as governed by the industry-standard ASME B16.9 for Factory-Made Wrought Butt-Welding Fittings.
Overview of ASME B16.9 Standard
ASME B16.9 is a recognized standard that specifies the dimensions, tolerances, and markings for wrought buttwelding fittings, including elbows, tees, reducers, and caps. For long radius elbows, the center-to-end dimension is defined as 1.5 times the nominal pipe size in inches, which promotes better flow characteristics compared to short radius elbows.
This standard applies to fittings made from various materials, including stainless steel grades like 304, and covers seamless and welded constructions. Dimensions are provided in both metric (mm) and US customary (inches) units.
ASME B16.9 90° Long Radius Elbows Dimension Parameters
The dimensional characteristics of 90° long radius elbows are defined by several critical parameters that determine their proper fit and function within piping systems:
Nominal Pipe Size (NPS): The standard diameter designation of the connecting pipe.
Outside Diameter (OD): The exterior measurement of the elbow ends, which must match the connecting pipe.
Center-to-End Dimension (A): The distance from the centerline intersection point to the end of the elbow.
Radius of Curvature (R): For LR elbows, this is standardized at 1.5 times the nominal diameter.
Wall Thickness: Varies by schedule number (e.g., Sch 5S, 10S, 40S, 80S) to match piping system requirements.
90° Long Radius Elbow Dimensions
|
NPS |
OD (mm/inch) |
Center-to-End A (mm/inch) |
|
1/2 |
21.3 / 0.84 |
38 / 1.50 |
|
3/4 |
26.7 / 1.05 |
38 / 1.50 |
|
1 |
33.4 / 1.32 |
38 / 1.50 |
|
1-1/4 |
42.2 / 1.66 |
48 / 1.88 |
|
1-1/2 |
48.3 / 1.90 |
57 / 2.25 |
|
2 |
60.3 / 2.38 |
76 / 3.00 |
|
2-1/2 |
73.0 / 2.88 |
95 / 3.75 |
|
3 |
88.9 / 3.50 |
114 / 4.50 |
|
3-1/2 |
101.6 / 4.00 |
133 / 5.25 |
|
4 |
114.3 / 4.50 |
152 / 6.00 |
|
5 |
141.3 / 5.56 |
190 / 7.50 |
|
6 |
168.3 / 6.62 |
229 / 9.00 |
|
8 |
219.1 / 8.62 |
305 / 12.00 |
|
10 |
273.0 / 10.75 |
381 / 15.00 |
|
12 |
323.8 / 12.75 |
457 / 18.00 |
|
14 |
355.6 / 14.00 |
533 / 21.00 |
|
16 |
406.4 / 16.00 |
610 / 24.00 |
|
18 |
457.0 / 18.00 |
686 / 27.00 |
|
20 |
508.0 / 20.00 |
762 / 30.00 |
|
22 |
559.0 / 22.00 |
838 / 33.00 |
|
24 |
610.0 / 24.00 |
914 / 36.00 |
|
26 |
660.0 / 26.00 |
991 / 39.00 |
|
28 |
711.0 / 28.00 |
1067 / 42.00 |
|
30 |
762.0 / 30.00 |
1143 / 45.00 |
|
32 |
813.0 / 32.00 |
1219 / 48.00 |
|
34 |
864.0 / 34.00 |
1295 / 51.00 |
|
36 |
914.0 / 36.00 |
1372 / 54.00 |
|
38 |
965.0 / 38.00 |
1448 / 57.00 |
|
40 |
1016.0 / 40.00 |
1524 / 60.00 |
|
42 |
1067.0 / 42.00 |
1600 / 63.00 |
|
44 |
1118.0 / 44.00 |
1676 / 66.00 |
|
46 |
1168.0 / 46.00 |
1753 / 69.00 |
|
48 |
1219.0 / 48.00 |
1829 / 72.00 |
45° Long Radius Elbow Dimensions
|
NPS |
OD (mm/inch) |
Center-to-End B (mm/inch) |
|
1/2 |
21.3 / 0.84 |
16 / 0.62 |
|
3/4 |
26.7 / 1.05 |
19 / 0.75 |
|
1 |
33.4 / 1.32 |
22 / 0.88 |
|
1-1/4 |
42.2 / 1.66 |
25 / 1.00 |
|
1-1/2 |
48.3 / 1.90 |
29 / 1.12 |
|
2 |
60.3 / 2.38 |
35 / 1.38 |
|
2-1/2 |
73.0 / 2.88 |
44 / 1.75 |
|
3 |
88.9 / 3.50 |
51 / 2.00 |
|
3-1/2 |
101.6 / 4.00 |
57 / 2.25 |
|
4 |
114.3 / 4.50 |
64 / 2.50 |
|
5 |
141.3 / 5.56 |
79 / 3.12 |
|
6 |
168.3 / 6.62 |
95 / 3.75 |
|
8 |
219.1 / 8.62 |
127 / 5.00 |
|
10 |
273.0 / 10.75 |
159 / 6.25 |
|
12 |
323.8 / 12.75 |
190 / 7.50 |
|
14 |
355.6 / 14.00 |
222 / 8.75 |
|
16 |
406.4 / 16.00 |
254 / 10.00 |
|
18 |
457.0 / 18.00 |
286 / 11.25 |
|
20 |
508.0 / 20.00 |
318 / 12.50 |
|
22 |
559.0 / 22.00 |
343 / 13.50 |
|
24 |
610.0 / 24.00 |
381 / 15.00 |
|
26 |
660.0 / 26.00 |
406 / 16.00 |
|
28 |
711.0 / 28.00 |
438 / 17.25 |
|
30 |
762.0 / 30.00 |
470 / 18.50 |
|
32 |
813.0 / 32.00 |
502 / 19.75 |
|
34 |
864.0 / 34.00 |
533 / 21.00 |
|
36 |
914.0 / 36.00 |
565 / 22.25 |
|
38 |
965.0 / 38.00 |
600 / 23.62 |
|
40 |
1016.0 / 40.00 |
632 / 24.88 |
|
42 |
1067.0 / 42.00 |
660 / 26.00 |
|
44 |
1118.0 / 44.00 |
695 / 27.38 |
|
46 |
1168.0 / 46.00 |
727 / 28.62 |
|
48 |
1219.0 / 48.00 |
759 / 29.88 |
180° Long Radius Return Dimensions
|
NPS |
OD (mm) |
Center-to-Center O (mm) |
Back-to-Face K (mm) |
|
1/2 |
21.3 |
76 |
48 |
|
3/4 |
26.7 |
76 |
51 |
|
1 |
33.4 |
76 |
56 |
|
1-1/4 |
42.2 |
95 |
70 |
|
1-1/2 |
48.3 |
114 |
83 |
|
2 |
60.3 |
152 |
106 |
|
2-1/2 |
73 |
190 |
132 |
|
3 |
88.9 |
229 |
159 |
|
3-1/2 |
101.6 |
267 |
184 |
|
4 |
114.3 |
305 |
210 |
|
5 |
141.3 |
381 |
262 |
|
6 |
168.3 |
457 |
313 |
|
8 |
219.1 |
610 |
414 |
|
10 |
273 |
762 |
518 |
|
12 |
323.8 |
914 |
619 |
|
14 |
355.6 |
1067 |
711 |
|
16 |
406.4 |
1219 |
813 |
|
18 |
457 |
1372 |
914 |
|
20 |
508 |
1524 |
1016 |
|
22 |
559 |
1676 |
1118 |
|
24 |
610 |
1829 |
1219 |
Wall Thickness Schedules
Stainless steel 304 long radius elbows are available in various wall thicknesses to match pipe schedules. Common options include:
|
NPS (DN) |
OD (mm) |
SCH 5S (mm) |
SCH 10S (mm) |
SCH 40S (mm) |
SCH 80S (mm) |
|
1/2 (15) |
21.3 |
1.65 |
2.11 |
2.77 |
3.73 |
|
3/4 (20) |
26.7 |
1.65 |
2.11 |
2.87 |
3.91 |
|
1 (25) |
33.4 |
1.65 |
2.77 |
3.38 |
4.55 |
|
1-1/4 (32) |
42.2 |
1.65 |
2.77 |
3.56 |
4.85 |
|
1-1/2 (40) |
48.3 |
1.65 |
2.77 |
3.68 |
5.08 |
|
2 (50) |
60.3 |
1.65 |
2.77 |
3.91 |
5.54 |
|
2-1/2 (65) |
73.0 |
2.11 |
3.05 |
5.16 |
7.01 |
|
3 (80) |
88.9 |
2.11 |
3.05 |
5.49 |
7.62 |
|
4 (100) |
114.3 |
2.11 |
3.05 |
6.02 |
8.56 |
|
6 (150) |
168.3 |
2.77 |
3.40 |
7.11 |
10.97 |
|
8 (200) |
219.1 |
2.77 |
3.76 |
8.18 |
12.7 |
|
10 (250) |
273.1 |
3.4 |
4.19 |
9.27 |
12.7 |
|
12 (300) |
323.9 |
3.96 |
4.57 |
9.53 |
12.7 |
Selecting the correct Stainless Steel 304 LR Elbow requires matching the NPS, angle, and wall schedule to your specific pipeline requirements, all strictly guided by the rigorous dimensional controls of the ASME B16.9 standard.
Do you have any specific Nominal Pipe Sizes (NPS) or Schedules you would like to inquire about for a detailed quote?
