Piping
Pipe fitting take offs
In short
The take-out of a buttweld fitting is its published centre-to-end dimension: A for a 90° elbow, B for a 45° elbow, C = M for an equal tee, H for a reducer, E for a cap. The calculation reads it from the EN 10253-2 or ASME B16.9 tables for the pipe size, then adds the root gap: E + j.
Calculation
Example calculated with the tool’s default values.
Inputs
- Standard
- EN 10253-2 (DN)
- Pipe
- DN100 · 114.3 × 3.6 mm
- Fitting
- 90° long radius elbow
- Root gap
- 0 mm
Results
- 90° long radius elbow: centre-to-end a
- 152.0 mm
Worked example
Every value in this section belongs to the example, calculated with the tool’s default values.
Other results of the example
- Standard dimension (no gap)
- 152.0 mm
- Size
- DN 100
- Table OD
- 114.3 mm
- Nominal standard dimensions: check the fitting received (tolerances ±2 to ±3 mm depending on size).
Step-by-step calculation
Table lookup
EN 10253-2, DN 100
Centre-to-end A = 152.0 mm
EN 10253-2, DN 100, OD 114,3
| Fitting | Dimension | Value (mm) | Origin |
|---|---|---|---|
| 90° long radius elbow | Centre-to-end A | 152.0 | EN 10253-2 |
| 45° long radius elbow | Centre-to-end B | 63.0 | R × tan 22.5° |
| 90° short radius elbow | Centre-to-end A | 102.0 | EN 10253-2 |
| Equal tee | Centre-to-end C = M | 105.0 | EN 10253-2 |
| Reducer (large end) | Length H | 102.0 | EN 10253-2 |
How to use it
- Pick the standard: EN 10253-2 (DN) or ASME B16.9 (NPS).
- Pick the pipe: its outside diameter selects the table row.
- Pick the fitting: 90° long radius elbow, 45° long radius elbow, 90° short radius elbow, equal tee, reducer (large end) or cap.
- Enter the root gap, added to the take-out.
- Read the centre-to-end dimension of the fitting, gap included.
Frequently asked questions
What is the elbow center to end formula?
For a 90° buttweld elbow, the centre-to-end dimension A equals the elbow radius: it is read from the standard's table for the pipe outside diameter. The root gap is then added: E + j. Example in DN 100 (OD 114.3), EN 10253-2 90° long radius elbow: centre-to-end A = 152 mm.
What are the elbow dimensions for long and short radius?
In EN 10253-2, the type 3D elbow has a radius of about 1.5 D and the type 2D about 1 D. In DN 100 (OD 114.3), the 90° type 3D elbow is 152 mm centre-to-end and the type 2D 102 mm. ASME B16.9 gives the same values in NPS 4: 152 mm long radius (LR), 102 mm short radius (SR).
What is the take-out of a 45° elbow?
ASME B16.9 publishes the centre-to-end B of the 45° long radius elbow: 64 mm in NPS 4 (OD 114.3). EN 10253-2 only gives the radius: the take-out is then computed as R × tan 22.5°, for a 45° elbow with the same radius as the 90° type 3D elbow.
What are the tee dimensions?
In DN 100 (OD 114.3), the equal tee is 105 mm centre-to-end, in EN 10253-2 as in ASME B16.9; the reducer is 102 mm end to end, from the large end. The cap, in ASME B16.9 only, has a height E of 64 mm.
Limits
Indicative results. Nominal standard dimensions: check the fitting received (tolerances ±2 to ±3 mm depending on size). Tables read from MAI Piping and PipeData (ASME B16.9-2018) and Zickwolff (EN 10253-2:2021+A1:2026); a size missing from the tables has no dimension. Do not mix the two standards: in small sizes, their elbows differ.
Sources
- EN 10253-2:2021+A1:2026 (raccords à souder bout à bout) : Coudes 2D/3D (rayon R), tés égaux (F), réductions (L) ; tableaux Zickwolff, consultés le 08/11/2026 (link)