Seamless Elbows from the Manufacturer – Type A & Type B to EN 10253-2
Nirotec manufactures seamless elbows in Unna, Germany – to EN 10253-2/-4 (design types 2, 3 and 5) in Type A and Type B and to ASME B16.9 (LR/SR), in 45° and 90° as well as custom angles from 15° to 180°, up to DN 600 (24") and seamless up to approx. 100 mm wall thickness.
The standard is the EN 10204 Type 3.1 inspection certificate, with Type 3.2 and third-party inspection on request – for power plants, nuclear technology, chemicals, refineries and apparatus and plant engineering, including small batch sizes.
Elbows at a glance
| Feature | Nirotec elbows |
|---|---|
| Standards | EN 10253-2/-4 (design types 2, 3 and 5, Type A and Type B), ASME B16.9 (LR / SR), EEMUA 234 for nickel alloys |
| Angles | 45° and 90° – custom angles from 15° to 180° on request |
| Dimensions | up to DN 600 (24"), seamless up to approx. 100 mm wall thickness |
| Manufacturing | Hot and cold forming on hydraulic presses with 1,500 t press force, heat treatment, machining |
| Materials | Carbon steel, low-temperature steel, creep-resistant CrMo steels incl. P91 / P92, stainless steel (e.g. 304L, 316L, 321, 347, 316Ti, 904L, 6Mo), duplex, super duplex, nickel-based alloys, CuNi 90/10 and 70/30 |
| Testing | Visual inspection, dimensional inspection, NDT (RT, UT, PT, MT), PMI, mechanical testing, hardness testing, ferrite measurement for duplex, tint verification for Type B |
| Certificates | Standard: EN 10204 Type 3.1 – Type 3.2 on request with inspection by e.g. TÜV, SGS, DNV, Lloyd’s Register, Bureau Veritas or customer representatives |
| Certifications | DIN EN ISO 9001:2015, ISO 19443:2018 (nuclear), CRN registration for Canada (ASME B16.9) |
| Batch sizes | small batch sizes, short lead times |
Type A or Type B – what is the difference?
In short: Type A is the design with standard wall thickness according to the standard. Type B has an increased minimum wall thickness at the intrados (inside of the bend), the tint dimension – for higher safety margins at high pressure and high temperature. Design type and Type A/B are independent of each other.
Type A – standard wall thickness
Elbows for general industrial piping applications. The wall thickness corresponds to the standard requirements of the norm.
Type B – increased wall thickness (t_int dimension)
Elbows with increased minimum wall thickness at the intrados. For Type B, the standard specifies a defined tint dimension that is significantly above the requirements of Type A.
The tint dimension describes the wall thickness at the intrados after forming. Because the inside of the bend is compressed during bending, the wall thickness changes. Type B ensures that the required minimum wall thickness is reliably maintained even after forming.
What Type B means in practice:
- The starting material (pipe) must be considerably thicker than for Type A
- Specially designed dies and forming tools are required
- Not every manufacturer is able to supply Type B
- Result: higher safety margins, better suitability for high pressure and high temperature
Combinations – design type and Type A/B are independent:
- Design type 2 (long-radius elbow, standard requirements) – as Type A or Type B
- Design type 3 (short-radius elbow, enhanced requirements) – as Type A or Type B
- Design type 5 (long-radius elbow, enhanced requirements) – as Type A or Type B
Typical applications for Type B:
- High-pressure and high-temperature piping in power plants
- Nuclear technology – safety-relevant systems (ITNS)
- Plants to AD 2000 or ASME with increased strength requirements
- Project-specific requirements of the client, EPC contractor or inspection authority
| Type A | Type B | |
|---|---|---|
| Wall thickness | Standard wall thickness according to the standard | increased minimum wall thickness at the intrados (tint dimension) |
| Starting pipe | Standard wall thickness | considerably thicker than for Type A, specially designed dies required |
| Verification | Standard tests | additional documented tint verification |
| Typical use | general industrial piping | high-pressure / high-temperature piping, power plants, nuclear technology, AD 2000 / ASME with increased requirements |
Nirotec supplies both types in design types 2, 3 and 5 and in all common materials. The tint verification is documented and handed over with the inspection certificates.
Manufacturing & properties
Our elbows are manufactured from seamless or welded pipes and are hot- or cold-formed depending on material, dimension and requirements – on hydraulic presses with up to 1,500 t press force. Specially designed pressing and forming processes ensure uniform material distribution and high dimensional accuracy. Depending on material and application, this is followed by heat treatment and machining.
Controlled manufacturing processes give us high roundness, uniform wall thickness distribution and reliable tightness of the components.
Typical designs & geometries:
- 45° and 90°
- Custom angles from 15° to 180° on request
- Long Radius (LR) / Short Radius (SR)
- Project-specific radii to customer specification
To ASME B16.9:
- LR (Long Radius): bend radius = 1.5 × DN – standard design for most piping systems
- SR (Short Radius): bend radius = 1.0 × DN – for tight space conditions
To EN 10253-2/-4:
- Design type 2 – long-radius elbow, standard requirements
- Design type 3 – short-radius elbow, enhanced requirements
- Design type 5 – long-radius elbow, enhanced requirements
- each as Type A or Type B (see difference above)
Special designs:
- Custom angles and radii to customer specification
- New dies from our own tool shop possible
- Extended ends (tangents) to drawing
- Heavy-wall designs beyond the standard
- Manufacturing to project-specific requirements (e.g. offshore / nuclear)
Quality testing & documentation
Manufacturing and testing within our quality management system to DIN EN ISO 9001 and ISO 19443. On request: PMI analyses, material testing, third-party inspection (TÜV, SGS)
All tests are documented with EN 10204 inspection certificates (3.1 or 3.2).
Overview of our testing services:
- Visual inspection
- Dimensional inspection and wall thickness measurement
- Non-destructive testing (UT, RT, PT, MT)
- tint verification for Type B elbows
- Positive Material Identification (PMI)
- Hardness testing
- Ferrite measurement for duplex materials
- Third-party inspection by TÜV, Bureau Veritas or customer inspectors
- Inspection certificates to EN 10204 (3.1 / 3.2)
- Project-specific ITPs with hold and witness points on request
Materials & standards
Our elbows are manufactured from a wide range of industrial materials. Depending on application, temperature, pressure and corrosion requirements, we supply components from different material groups.
Further materials and project-specific material requirements on request.
Unalloyed & low-alloy steels:
P235GH / 1.0345
P265GH / 1.0425
P355N / 1.0562 · P355NH / 1.0565
L360 / 1.0582 / API 5L X52
L415 / 1.8972 / API 5L X60
WPB / A234 WPB / Carbon Steel
WPHY70 / A860 WPHY70
Low-temperature steels:
WPL3 / A420 WPL3
WPL6 / A420 WPL6
LF2 / A350 LF2
P355NL2
P460NL2
10Ni14
12Ni14 / 1.5637
Creep-resistant steels:
16Mo3 / 1.5415
WP11 / P11 / 1.7335 / 13CrMo4-5
WP22 / P22 / 1.7380 / 10CrMo9-10
WP91 / P91 / 1.4903 / X10CrMoVNb9-1
WP92 / P92 / 1.4901 / X10CrWMoVNb9-2
X20 / 1.4922 / X20CrMoV11-1
WB36 / 1.6368 / 15NiCuMoNb5
Austenitic stainless steels:
304 / 1.4301 / X5CrNi18-10 / V2A
304L / 1.4307 / X2CrNi18-9 / TP304L / WP304L
316L / 1.4404 / X2CrNiMo17-12-2 / TP316L / WP316L / V4A
316Ti / 1.4571 / X6CrNiMoTi17-12-2 / TP316Ti / WP316Ti
321 / 1.4541 / X6CrNiTi18-10 / TP321 / WP321
347H / 1.4961 / TP347H / WP347H
310S / 1.4845 / X8CrNi25-21 / TP310S / WP310S
Duplex & Super Duplex
Duplex / 1.4462 / X2CrNiMoN22-5-3 / UNS S31803 / F51
Super Duplex / 1.4410 / X2CrNiMoN25-7-4 / UNS S32750 / F53
Super Duplex / 1.4501 / X2CrNiMoCuWN25-7-4 / UNS S32760 / F55
254SMO / 1.4547 / X1CrNiMoCuN20-18-7 / UNS S31254
Alloy 926 / 1.4529 / X1NiCrMoCuN25-20-7 / UNS N08926
904L / 1.4539 / X1NiCrMoCu25-20-5 / UNS N08904
Nickel alloys:
Monel 400 / 2.4360 / UNS N04400
Alloy 625 / 2.4856 / UNS N06625 / Inconel 625
Alloy 825 / 2.4858 / UNS N08825 / Incoloy 825
Alloy C-276 / 2.4819 / UNS N10276 / Hastelloy C-276
Alloy 718 / 2.4668 / UNS N07718
Alloy 800H / 1.4876H / UNS N08810
Alloy C-22 / 2.4602 / UNS N06022 / Hastelloy C-22
Copper-nickel & special materials:
CuNi10Fe1Mn / 2.0872 / C70600 / CuNi 90/10
CuNi 70/30 / 2.0882 / C71500
Zirconium 702 / UNS R60702
Frequently asked questions about elbows
What is the difference between Type A and Type B to EN 10253-2?
Type A is the design with standard wall thickness according to the standard. Type B has an increased minimum wall thickness at the intrados (tint dimension), which is reliably maintained even after forming. This provides higher safety margins – which is why Type B is used above all in high-pressure and high-temperature piping, in power plants and in nuclear technology.
Which design types and radii are available?
To EN 10253-2/-4, design types 2, 3 and 5; to ASME B16.9, Long Radius (LR, bend radius 1.5 × DN) and Short Radius (SR, 1.0 × DN). We manufacture project-specific radii and custom angles from 15° to 180° on request.
Up to what size does Nirotec manufacture seamless elbows?
Up to DN 600 (24") and seamless up to approx. 100 mm wall thickness. Heavy-wall designs beyond the standard are possible on request.
Which inspection certificates do I receive?
The standard is the EN 10204 Type 3.1 inspection certificate with traceability back to the heat. On request, you receive Type 3.2 with inspection by TÜV, SGS, DNV, Lloyd’s Register, Bureau Veritas or your customer representatives – for projects and in nuclear technology with an agreed ITP.
Does Nirotec also supply small quantities and custom angles?
Yes. We also manufacture small batch sizes with short lead times, custom angles from 15° to 180° and extended ends (tangents) to drawing.
What information do you need for a quotation?
Standard / design (e.g. ASME B16.9 LR or EN 10253 design type 3), material grade and any heat restriction, dimensions (DN / NPS, wall thickness or schedule), quantity and requested delivery date, and the required documentation (3.1 / 3.2, NDT, third-party inspection). Alternatively, simply send us your drawing or parts list.
As of: September 2026
Applications & industries
In use worldwide
Thanks to their dimensional accuracy and resilience, our fittings are ideal for pressure, temperature and corrosion environments with the highest safety requirements.
Energy & Power Plants
Nuclear Technology
Hydrogen & Energy Infrastructure
Chemical & Process Industries
Refineries & Offshore Facilities
Apparatus & Mechanical Engineering
Looking for special dimensions or special materials?
At Nirotec, we also manufacture elbows outside the standard range – heavy-wall, in special materials and with extended ends. Contact our sales team directly.
For a quick quotation we need: standard / design (e.g. ASME B16.9 LR or EN 10253 design type 3), material grade and any heat restriction, dimensions (DN / NPS, wall thickness or schedule), quantity and requested delivery date, and the required documentation (3.1 / 3.2, NDT, third-party inspection).
