Centre-line radius 5 × D | Piggable | 2" – 48"
A 5D pipe bend has a centre-line radius five times the pipe diameter: a 16" 5D bend has a radius of about 80" (2,032 mm). It is the standard choice for piggable oil and gas pipelines, pig launcher and receiver areas, and lines where pressure drop and erosion must be kept low. We supply 5D bends by hot induction bending with tangents to your length, with ovality and wall thinning measured and reported on every bend.
| Radius | 5 × D (centre line) |
| Size | 2" – 48" NPS |
| Wall | SCH 20 – XXS, or wall in mm |
| Angle | Any, up to 180° |
| Piggable | Yes, ovality to your limit |
| Tangents | As specified |
| Codes | ASME B16.49, ISO 15590-1 / EN 14870-1, project spec |
| Documents | EN 10204 3.1 std, 3.2 on request |
Inspection pigs carry sensors, magnets and cups that must pass through every change of direction. Many operators and pig suppliers set 5D as the minimum bend radius for intelligent pigging, while 3D is accepted for some cleaning and gauging pigs. The larger radius also reduces pressure drop and erosion on the outside of the bend.
A 5D bend is formed from straight pipe by hot induction bending. The heated band is narrow, so the bend is formed gradually and the ovality and wall thinning stay within close limits. The straight tangents at each end make field welding and radiography easier, because the weld is away from the bent section.
Please give us the ovality limit and the minimum bend radius from your pig supplier. We plan the mother pipe and bending parameters to meet them and report the measured values bend by bend.
| NPS | Pipe OD (mm) | 5D radius on nominal size (mm) | 5D radius on OD (mm) |
|---|---|---|---|
| 4" | 114.3 | 508 | 572 |
| 6" | 168.3 | 762 | 842 |
| 8" | 219.1 | 1,016 | 1,096 |
| 10" | 273.1 | 1,270 | 1,366 |
| 12" | 323.9 | 1,524 | 1,620 |
| 16" | 406.4 | 2,032 | 2,032 |
| 24" | 609.6 | 3,048 | 3,048 |
From NPS 14 upwards the outside diameter equals the nominal size in inches, so both methods give the same radius.
API 5L Gr B and X42–X70 PSL2, sour service to NACE MR0175 / ISO 15156 on request, EN L360NB / L415
P11, P22, P91, 13CrMo4-5, 10CrMo9-10 for steam and hot oil lines
316L, 321, duplex 2205 (1.4462), super duplex 2507
A 5D pipe bend has a centre-line radius equal to five times the pipe diameter. For example, a 12" 5D bend has a radius of about 60" (1,524 mm). It is made by induction bending a length of pipe and usually has straight tangents at each end.
Intelligent inspection pigs are long and rigid, so they need a large bend radius to pass. Many operators specify 5D as the minimum for piggable pipelines. The bend must also meet an ovality limit so the pig cups seal and the tool does not get stuck.
It depends on the specification. Many use nominal pipe size, some use outside diameter. Below NPS 14 the two give different radii (a 10" 5D bend is 1,270 mm on nominal size and 1,366 mm on OD), so state the basis in your order.
Yes. Tangent lengths are made to order and can be different at each end. Long tangents keep the field weld away from the bent section and make radiography easier. Tell us the tangent lengths and the end preparation you need.
Yes, on request, in pipeline grades with hardness control and testing to NACE MR0175 / ISO 15156. State sour service and any HIC or SSC test requirements in the RFQ.
Reply from our Mumbai sales office, usually within one working day. You can attach drawings by email to marketing@arshyafittings.com.
