Seamless tees for industrial piping systems
We manufacture seamless tees for industrial piping systems – in our own production facility in Unna, using cold and hot forming as well as IHU processes (internal high-pressure forming). Our tees are used in power plant construction, the chemical industry, refineries, and equipment and plant engineering, among other applications.
From standard dimensions to thick-walled special dimensions in P91 or Super Duplex, we supply compliant solutions to EN 10253-2 Type A and Type B for demanding applications.
Manufacturing & Properties
Our tees are manufactured from seamless or welded pipes and, depending on material, dimension, and requirements, are hot or cold formed or produced from pipe sections. The transition geometry is formed using specially designed forming and manufacturing processes that ensure uniform material distribution and high dimensional accuracy.
Through controlled manufacturing processes, we achieve uniform transitions, optimized wall thickness distribution, and reliable tightness.
Typical designs:
To EN 10253 and ASME B16.9:
- Equal tees
- Reducing tees
Special designs:
- Extended run sides to customer specifications
- Extended branch to drawing
- Special diameter combinations outside the standard
- Ultra-thick-walled designs – e.g., 323.9 × 50 mm in P91
- Asymmetric tees to drawing
Technical specifications
- Wall thicknesses up to 50 mm and more
- Thick-walled designs with verification of Ts and Tb dimensions for safety-critical applications
- Diameters up to 610 mm
- Hydraulic presses 150 to 1,500 tons
- IHU process for precise transition geometries
- Heat treatment in in-house furnace
Standards & Regulations
- EN 10253-2 / EN 10253-4 Type A and Type B – Seamless pipe fittings Europe
- ASME B16.9 – Factory-Made Wrought Buttwelding Fittings
- EN 13480 – Metallic industrial piping
- AD 2000 – Pressure equipment Germany
- ASME B31.1 – Power Piping
- ASME B31.3 – Process Piping
- ASME B31.12 – Hydrogen Piping
- NORSOK M-630 – Offshore piping components
- KTA 3201 / RCC-M – Nuclear engineering
- Project-specific specifications and drawings on request
Type A and Type B to EN 10253-2
Nirotec has the manufacturing competence to supply tees to EN 10253-2 in Type A and Type B. Compliance with the Ts and Tb dimensions is verified during quality inspection and fully documented.
Type A – Standard wall thickness
Tees for general industrial piping applications to standard requirements.
Type B – increased wall thicknesses (Ts dimension and Tb dimension)
Tees with increased minimum wall thicknesses at the geometrically and technically most demanding locations. The standard defines two relevant parameters for Type B:
- Ts dimension: Minimum wall thickness at the apex of the branch (transition run pipe / branch)
- Tb dimension: Minimum wall thickness at the base of the branch (branch foot)
Both values are significantly higher for Type B than the requirements for Type A – at precisely those locations that are subjected to the greatest stress during forming.
What Type B means in practice:
- The starting material 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 at the critical locations of the geometry
Typical applications for Type B:
- High-pressure and high-temperature lines in power plants and process facilities
- Nuclear engineering – safety-relevant systems (ITNS)
- Facilities to AD 2000 or ASME with increased strength requirements
- Project-specific requirements of the client, EPC contractor, or inspection authority
Materials & Standards
Our tees are manufactured from a wide range of industrial materials. Depending on application, temperature, pressure, and corrosion requirements, we supply components from different material groups.
Standard specifications:
- EN 10253-2 (Type A and Type B)
- ASME B16.9
- AD 2000
- PED 2014/68/EU
Additional materials and project-specific material requirements on request.
Unalloyed & low-alloy steels:
P235GH / 1.0345
P265GH / 1.0425
P355GH / 1.0566
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
Heat-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 / 1.4912 / X7CrNiNb18-10 / 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:
CuNi10Fe1.6Mn / C70600 / 90-10 CuNi
CuNi70/30 / C71500
Zirconium 702 / UNS R60702
Quality Inspection & Documentation
Manufacturing and inspection within our QM system to ISO 9001 and AD 2000. Typical inspection services:
- Visual inspection
- Dimensional control and wall thickness measurement
- Non-destructive testing (UT, RT, PT, MT)
- Verification of Ts and Tb dimensions for Type B tees
- Positive material identification (PMI)
- Hardness testing
- Ferrite measurement for duplex materials
- External inspections by TÜV, Bureau Veritas, or customer inspectors
- Test certificates to EN 10204 (3.1 / 3.2)
- Project-specific ITPs with hold and witness points on request
Applications & Industries
In use worldwide
Thanks to their dimensional accuracy and load-bearing capacity, our tees are ideally suited for pressure, temperature, and corrosion environments with the highest safety requirements.
Energy and Power Plant Facilities
Nuclear Technology
Hydrogen and Energy Infrastructure
Chemical and Process Industry
Refineries and Offshore Facilities
Apparatus and Mechanical Engineering
Looking for a special dimension or special material?
At Nirotec, we also manufacture tees outside the standard range – thick-walled, in special materials, with extended run sides. Contact our sales team directly.