An induction bend is made by heating a narrow band of straight pipe with an induction coil and pushing the pipe through it, so the bend forms progressively with controlled wall thinning on the outside of the curve and thickening on the inside. The result is a smooth, ovality-controlled sweep that keeps flow resistance and pigging behaviour close to straight pipe — which is why cross-country pipelines and plant lines with long runs specify bends instead of elbows at key turns.
The radius defines the bend: 3D is a tight pipeline bend, 5D the common standard, 8D and above for gentle sweeps. Tangent (straight) lengths at each end are part of the bend specification — state the lengths your line needs on the enquiry and they are confirmed for the specific product before order.
| Item | Range / Options |
|---|---|
| Types | Induction bends; hot-formed long bends (R = 2.5D DIN pattern listed) |
| Bend radii | 3D, 5D, 8D in the catalogue induction bend listings; the DIN-pattern long bend is listed at R = 2.5D |
| Catalogue listings | Induction bends in 3D / 5D / 8D radii; long bend, R = 2.5D, DIN pattern |
| Size range | By mother pipe, radius and wall — confirmed per product at enquiry |
| Wall thickness | Specified with the mother pipe grade; state the required minimum wall on the enquiry |
| Materials | Per the catalogue bend listings; the grade for a specific bend is confirmed per product at enquiry |
Bend, or Elbow?
An elbow is a standard catalogue fitting with a 1.5D or 1D radius, priced per piece. A bend is made to order for a specific angle, radius and tangent length, and earns its cost where the line is long, pigged, or pressure-drop sensitive. If your isometric shows a radius above 1.5D, or a non-standard angle such as 30° or 60° at a wide sweep, you are looking at a bend, not an elbow — our elbow page covers the standard fittings.
How Bends Are Specified
State the mother pipe (size, wall, grade), the bend radius as a multiple of nominal diameter, the bend angle, and the tangent length required at each end. Coating and bevel requirements are stated the same way, on the enquiry, and confirmed for the specific product before order. Because bends are made from the actual pipe grade, mechanical properties carry through the bend.
Applications
Oil and gas transmission and gathering lines, district energy, slurry and water pipelines, and plant piping where wide sweeps reduce erosion and pressure loss at direction changes.
Frequently Asked Questions
What does 3D, 5D and 8D mean?
The bend radius expressed as a multiple of the nominal pipe diameter. A 5D bend in NPS 12 has a centreline radius of 60 inches. Larger multiples give a gentler sweep, lower pressure drop and easier pig passage.
Can bends be made in angles other than 90 and 45 degrees?
A bend is made for a stated angle rather than picked from a standard elbow pattern, which is the main reason to choose one. The catalogue listings on this page record induction bends and a DIN-pattern long bend; state the angle your drawing requires on the enquiry and it will be assessed for the specific product before order.
Do induction bends keep the pipe's wall thickness?
Induction bending thins the outer wall and thickens the inner wall in a controlled way; the mother pipe is selected and the process controlled so the finished bend meets the design wall requirement. State the required minimum wall on the enquiry.
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Send Your Specification
Tell us the size, schedule or pressure class, material grade and quantity for the pipe bends you need. MOQ and lead time are confirmed in the quotation for your exact specification.