Longitudinally welded stainless steel tubes produced by laser/TIG/plasma welding from Cr, CrNi, duplex and nickel-based alloys
Hartmann Edelstahlrohre GmbH
Bochumer Straße 2, 57234 WilnsdorfNew on Amplifa
Tube manufacturing from a single source
Hartmann Edelstahlrohre GmbH from Wilnsdorf has been manufacturing longitudinally welded stainless steel tubes using laser, TIG and plasma welding processes for more than 30 years. The product range includes heat exchanger tubes, piping tubes with internal roughness depths of max. 0.8 µm as well as construction tubes in round, ellipse, oval, profile and special shapes. Dimension range: 4 to 120 mm cross-section (or 4 to 76.1 mm diameter according to the trade article), wall thicknesses 0.5 to 4.0 mm, production lengths up to 42,000 mm; fixed lengths from 15 to 3,000 mm with tolerance ±0.1 mm. The tubes are cold-formed or annealed/pickled in line; surfaces are ground or polished. Cr, CrNi, duplex (e.g. 1.4462) and nickel-based alloys are used. All production steps – from tool manufacturing to sawing, punching, grinding and bending through to quality control with laser measurement, eddy current testing and optical weld seam inspection – are carried out in-house. Customers include, among others, the process industry, apparatus and heat exchanger construction, architecture, the electrical industry and medical technology.
- Site
- Wilnsdorf
- Processes
- Longitudinal welding of stainless steel tubes using laser/TIG/plasma processes, Cold forming of tubes, In-line annealing/pickling, Surface grinding and polishing to roughness depth/gloss level (bright metal finish), Tube bending (individually bent tubes, digitally controlled bending process with simulation), Sawing, Punching, Tool manufacturing (including sharpening of saw blades)
- Materials
- Cr alloys, CrNi alloys, Duplex alloys, Nickel-based alloys, Duplex stainless steel 1.4462
- Certificates
- ISO 9001, Individual acceptances (AD2000-W2, DVGW, DNV, Lloyd's, GL, GOST, BV, TÜV)
- Industries
- Process industry, Apparatus engineering, Heat exchanger construction, Architecture, Electrical industry, Medical technology
- 01
Tool manufacturing in-house
- 02
Strip storage (fully automatic)
- 03
Tube welding (laser/TIG/plasma)
- 04
Cold forming or in-line annealing/pickling
- 05
Sawing, punching, bending
- 06
Grinding and polishing
- 07
Quality control (laser measurement, eddy current testing, optical weld seam
- 08
100% length inspection with optical cut-edge inspection
Materials & Processes
Cr alloys
Stainless steels with chromium content for corrosion-exposed tube applications.
CrNi alloys
Chromium-nickel steels for stainless steel tubes with high demands on corrosion resistance.
Duplex alloys
Duplex stainless steel for extreme environmental conditions, including 70,000 individual tubes for the Ithra facade.
Nickel-based alloys
For tubes in highly corrosive and temperature-exposed applications.
Wilnsdorf Site
Wilnsdorf
DEProduction and administration
- Materials
- Cr, CrNi, duplex and nickel-based alloys
- Laser/TIG/plasma welding systems
- Fully automatic strip storage systems
- Bending and measuring machines (networked, digitally controlled bending process)
- Eddy current testing lines
- In-line laser measurement system
- Profile scanner for tube geometry measurement
- Optical weld seam scanner (< 10 µm defect detection)
- Nitrogen generation plant
- Electrolysis plant for hydrogen production
- Photovoltaic system (420 kW)
- Compressor systems with heat exchangers
Components
Inside the production
Industries
Processes & technical limits
| Processes | Tolerance | Max. part | Weight | Lot size | Materials |
|---|---|---|---|---|---|
| Longitudinal welding of stainless steel tubes using laser/TIG/plasma processesJoining | ±0.1 mm (fixed lengths) · Internal roughness depth max. 0.8 µm | 42,000 mm (max. production length) | – | – | Cr alloys, CrNi alloys, Duplex alloys, Nickel-based alloys, Stainless steel 1.4462 |
| Cold forming of tubesForming | – | 42,000 mm | – | – | Stainless steel, Duplex |
| In-line annealing/picklingHeat treatment | – | – | – | – | Stainless steel |
| Surface grinding and polishing to roughness depth/gloss level (bright metal finish)Surface | – | – | – | – | Stainless steel |
| Tube bending (individually bent tubes, digitally controlled bending process with simulation)Forming | – | – | – | – | Duplex stainless steel 1.4462 |
| SawingMachining | – | – | – | – | Stainless steel |
| PunchingForming | – | – | – | – | Stainless steel |
| Tool manufacturing (including sharpening of saw blades)Engineering | – | – | – | – | – |
| Testing | – | – | – | – | Stainless steel |
| Eddy current testingTesting | – | – | – | – | Stainless steel |
| Optical weld seam inspection (detection of defect patterns in the seam below 10 µm)Testing | – | – | – | – | Stainless steel |
10 Anlagen & Maschinen
| Machine | Manufacturer / model | Quantity | Working area | Year built | Site |
|---|---|---|---|---|---|
| Eddy current testing lines | – | – | – | – | Wilnsdorf |
| Profile scanner for optical and physical measurement of tube geometries | – | – | – | – | Wilnsdorf |
| Optical weld seam scanner | – | – | Detects defect patterns < 10 µm | 2024 | Wilnsdorf |
| In-line laser measurement system for tube geometries | – | – | – | – | Wilnsdorf |
| Nitrogen generation plant | – | 1 | over 60,000 m³/year (edelstahl_aktuell.pdf) or over 130,000 m³/year (Heatexchanger.pdf) | 2023 | Wilnsdorf |
| Electrolysis plant for hydrogen production | – | 1 | – | 2025 | Wilnsdorf |
| Bending and measuring machines (networked, digitally controlled bending process) | – | – | – | – | Wilnsdorf |
| Fully automatic strip storage systems | – | – | – | – | Wilnsdorf |
| Compressor systems with heat exchangers | – | 2 | – | 2022 | Wilnsdorf |
| Photovoltaic system | – | 1 | approx. 3,000 m² of hall roof area, peak output 420 kW | 2023/2024 | Wilnsdorf |
Additional services
Reference customers
Quality & Testing
Quality assurance includes in-line laser measurement of tube geometries, extended eddy current testing lines, an optical weld seam scanner with defect detection below 10 µm as well as 100% length inspections with optical cut-edge inspection. Individual inspections/acceptances per AD2000-W2, DVGW, DNV, Lloyd's, GL, GOST, BV and TÜV are possible.
| Evidence | Wilnsdorf |
|---|---|
| ISO 9001 | |
| Individual acceptances (AD2000-W2, DVGW, DNV, Lloyd's, GL, GOST, BV, TÜV) |
History
- ca. 1990
Company founded; manufacturing of stainless steel tubes for over 30 years ('35 years of competence in stainless steel tubes').
- 2022
Conversion of lighting to LED, replacement of the company fleet with electric/hybrid vehicles with own charging infrastructure, installation of two compressor systems with heat exchangers.
- 2023
Commissioning of the photovoltaic system (approx. 3,000 m² roof area, 420 kW peak output) and the nitrogen generation plant.
- 2024
First expansion stage of the photovoltaic system; development and commissioning of an optical weld seam scanner (defect detection < 10 µm).
- 2025
Commissioning of the electrolysis plant for own hydrogen production – completion of decarbonization; first company in Westphalia with a fully CO2-free hydrogen and nitrogen supply.
- 2026
Trade article in Heat Exchanger World; manufacturing of tubes for the Ithra facade (approx. 70,000 individual duplex tubes 1.4462, 350 km total length, via seele).