Carbon steel and district heating
District heating and steel pipe welding. Including out-of-position work.
Herdi GmbH welds district heating pipework and steel pipework in unalloyed and low-alloy steel. Out-of-position welding is one of our strengths. We weld in positions PA to PG (ISO 6947) and produce welds for pipework systems with demanding quality requirements.
- Response within 24 hours
- Worldwide. A welder can be on site in Europe in 3 to 4 days
- Based in Herne, experience since 2006
Out-of-position welding is routine for us.
Pipework is rarely conveniently positioned. We weld in positions PA to PG (ISO 6947), including out-of-position work and on pipework already fixed in place.
Welds intended for radiographic testing.
For pipework systems with demanding quality requirements, we produce welds intended for radiographic (X-ray) testing. Radiographic testing (RT) itself is available on request.
Our pipework services.
- Welding district heating pipework
- Working with unalloyed and low-alloy steels
- Out-of-position welding, PA to PG
- Welds intended for radiographic (X-ray) testing
- Pipe fabrication and installation
- Repairs and refurbishment work
Rotate
One joint, one circumferential weld.
Insulated district heating pipe: steel pipe with a circumferential butt weld, PUR foam and a plastic jacket. Drag or use the arrows to rotate.
Illustrative 3D model, not a component from a Herdi assignment.
Frequently asked questions
Brief answers.
Do you weld district heating pipework?
Yes. Welding district heating pipework and steel pipework in unalloyed and low-alloy steel is among our main applications, along with pipe fabrication, installation and repairs.
Which welding positions do you cover?
Positions PA to PG (ISO 6947). As well as the flat position PA, these include out-of-position welding such as overhead (PE), vertical up (PF) and vertical down (PG).
Do your welds pass radiographic testing?
We produce welds intended for radiographic testing. We do not promise a test result in advance. Radiographic testing (RT) is available on request.
Do you come to site to work on the pipework?
Yes. A welder can be on site in Europe in 3 to 4 days.
Key terms explained
- Carbon steel
- The German term “Schwarzstahl” informally describes steel with a dark mill-scale layer from production. It does not specify a material grade.
- Out-of-position welding
- A welding position other than the convenient flat position PA. ISO 6947 identifies positions with letters, including PE for overhead, PF for vertical up and PG for vertical down.
- Radiographic testing (RT)
- Non-destructive testing of a weld using X-rays or gamma rays.
Your contact: Musab Köksal, Herdi GmbH. Updated: 30 September 2026.
Enquiry
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