4130 fittings
4130 elbows: 45°, 90° and 180° butt-weld
Long and short radius elbows and 180° returns in AISI 4130, made seamless to ASME B16.9 dimensions with heavy walls for high-pressure lines.
4130 elbows turn a high-pressure line through 45°, 90° or 180°. A long radius elbow has a center-to-end of 1.5 times the nominal size and a short radius elbow 1 times it; for gentler turns there are long sweep elbows. We make 4130 elbows seamless, to ASME B16.9 dimensions, in Sch 80 to XXS and heavier walls, heat treated for 7,500 to 15,000 psi service.
Long radius, short radius or long sweep
| Type | Center-to-end, 90° | When to use it |
|---|---|---|
| Long radius (LR) | 1.5 x nominal size (ASME B16.9) | The default for most lines |
| Short radius (SR) | 1 x nominal size (ASME B16.28 tables) | Where space is tight; more turbulence and wear |
| Long sweep | To drawing; our 2 in long sweep has 8 in | Erosive or high-velocity lines such as choke, kill, cement and mud |
ASME B16.9 elbow dimensions
| NPS | 90° long radius, A | 45° long radius, B | 90° short radius, A |
|---|---|---|---|
| 1 | 1.50 (38) | 0.88 (22) | 1.00 (25) |
| 1-1/2 | 2.25 (57) | 1.12 (28) | 1.50 (38) |
| 2 | 3.00 (76) | 1.38 (35) | 2.00 (51) |
| 2-1/2 | 3.75 (95) | 1.75 (44) | 2.50 (64) |
| 3 | 4.50 (114) | 2.00 (51) | 3.00 (76) |
| 4 | 6.00 (152) | 2.50 (64) | 4.00 (102) |
| 5 | 7.50 (191) | 3.12 (79) | 5.00 (127) |
| 6 | 9.00 (229) | 3.75 (95) | 6.00 (152) |
| 8 | 12.00 (305) | 5.00 (127) | 8.00 (203) |
Dimensions are the same for every wall thickness. Heavy-wall elbows keep these center-to-end values with the wall and bore of your drawing.
Wall thickness at the bend
When an elbow is formed, the outside of the bend (the extrados) stretches and thins while the inside (the intrados) thickens. ASME B16.9 holds the wall at any point to at least 87.5% of the nominal wall. On heavy-wall and erosive lines, state a minimum wall at the extrados, or order the next heavier wall, because the outside of the bend is also where solids strike. State it on the order so the wall is checked and recorded before the elbow ships.
180° returns
180° returns, in long and short radius, turn a line back on itself in loops and compact manifold runs. They are made in AISI 4130 to the same walls and heat treatments as the elbows, with dimensions to ASME B16.9 and B16.28.
Turns in choke and kill lines
API Standard 53 asks for choke and kill lines to be as straight as possible, and for targets or fluid cushions at 90° block ells, tees and bends with a radius under 10 times the pipe diameter. A long radius elbow, at 1.5 times, counts as a short-radius bend in that sense. How designers handle this, with targeted tees, cushions or long sweeps, is set out in long sweep bends vs targeted tees.
Ordering
90° long radius elbow, 4 in, XXS, butt weld to ASME B16.25, AISI 4130 quenched and tempered, 75 ksi min yield, 95 ksi min tensile, min wall at extrados 0.59 in, EN 10204 3.1, 8 pcs
Frequently asked questions
Long radius or short radius?
Long radius is the default: its center-to-end is 1.5 times the nominal size, so flow turns more gently and the outer wall wears more slowly. Use short radius, 1 times the nominal size, only where space forces it. Where erosion is the concern, a long sweep elbow with a much larger radius is the better choice.
Can a 4130 elbow be made with a heavier wall than XXS?
Yes. Heavy-wall elbows are made to the same center-to-end with the wall and bore your drawing gives, for example to match 5.5 in OD by 3 in ID pipe.
Do elbows need targets in a choke line?
Under API Standard 53, block ells and bends with a radius under 10 times the pipe diameter need a target or fluid cushion facing the flow in choke and kill lines. A long radius elbow is far below that, so treat it as a short-radius bend there. See long sweep bends vs targeted tees.