Membrane walls & finned tubes
The gas-tight wall of the furnace – tube to fin to tube, welded into one surface. We supply membrane walls and finned tubes to your drawing, with openings, nozzles and full documentation.
What is a membrane wall?
A membrane wall is a gas-tight surface of parallel tubes joined lengthwise by flat fins – hence also finned tube wall. It forms the furnace enclosure: inside, the water in the tube takes up the heat; outside, the fin holds back the flue gas. Tube pitch, fin width and the flatness of the finished panel govern the result, because any distortion carries over the full wall height on site.
Scope of supply & execution
| Item | Detail |
|---|---|
| Basis of manufacture | Drawing with tube pitch, fin width, openings and nozzle positions |
| Tube sizes | Ø 31.8 to 76.1 mm, wall thickness as designed |
| Fins | flat bar 12 to 40 mm wide, thickness as specified |
| Welding | longitudinal seams to a qualified procedure (WPS/WPQR) |
| Panel sizes | width usually to 2000 mm, length limited by transport |
| Openings | burner ports, sight and cleaning openings, nozzles to drawing |
| Materials | P235GH, P265GH, 16Mo3, 13CrMo4-5, 10CrMo9-10, stainless, Alloy 625 |
| Testing | dimensional and flatness check, visual weld inspection, pressure test on request |
| Documentation | 3.1 or 3.2 certificate to EN 10204, welding and dimensional report |
Materials we supply for this
The grade follows from medium, temperature and pressure. Each grade has a data sheet with composition, properties and standards.
Typical fields of use
- Furnace walls in steam generators and power station boilers
- Waste incineration with Alloy 625 weld overlay against corrosion
- Biomass boilers with high chlorine load in the flue gas
- Heat recovery boilers behind gas turbines and engines
- Repair panels where wall thickness has fallen below the minimum
- Retrofitting of burner and cleaning openings
The records you receive
Inspection certificate 3.1 or 3.2 to EN 10204
Batch-related test results for every pressure-bearing item, countersigned on request.
Non-destructive testing
Visual, penetrant, magnetic particle, ultrasonic or radiographic testing of the welds as specified.
Pressure test
Hydrostatic test to the applicable code and drawing, with test report.
Traceability
Batch and heat number of every item remain traceable through the documentation.
From drawing to delivery
1. Drawing or sketch
Send us the drawing, isometric or bill of material – a hand sketch with dimensions is enough to start.
2. Agree material and code
We settle grade, standard, pressure rating and the required certificate with you.
3. Quotation
You receive a quotation with price, execution and a firm delivery date.
4. Delivery with documentation
The component arrives ready to install, with certificates and test reports.
Membrane walls & finned tubes – frequently asked questions
What is the difference between a finned tube and a membrane wall?
The finned tube is the single part – a tube with flat fins welded on. The membrane wall is the panel assembled from them, that is several finned tubes welded into one gas-tight surface. We supply both to drawing.
Why does flatness matter so much?
Because distortion accumulates over the wall height. Longitudinal welding shrinks the panel; without countermeasures it no longer meets the adjoining wall on site. The permissible deviation therefore belongs on the drawing.
Is weld overlay with Alloy 625 possible?
Yes. In waste incineration and biomass boilers it is standard against chlorine corrosion. Two to three millimetres of overlay are usual, checked for layer thickness and bonding. State the required minimum thickness and the iron content limit.
Up to what panel width can it be transported?
Widths to 2000 mm are usual; length is set by transport, not by the technology. Larger walls are split into panels and welded on site – the split should be agreed with erection early.
What do you need for a quotation?
Drawing with tube pitch, fin width, tube size and wall thickness, material grade, position and size of openings, details of any weld overlay and the required certificate to EN 10204.
Membrane walls & finned tubes – request a quote
Drawing, material and quantity are enough – we come back with price and lead time.