Pipe coils & heating batteries
Bent tube runs that take up or give off heat – economisers, evaporators, cooling and heating coils. We supply pipe coils to your drawing, cold-bent to radius, tested and documented.
What is a pipe coil?
A pipe coil is a tube run bent several times so that a large heat transfer area fits into a small space. It is used wherever heat passes between two media – as an economiser in the flue gas pass, as an evaporator, as a cooling coil in a vessel or as a heating battery in air handling. Unlike the superheater coil it works in the medium temperature range and is usually made from unalloyed or low-alloy boiler tube.
Scope of supply & execution
| Item | Detail |
|---|---|
| Basis of manufacture | Drawing or isometric with radii, pitch and connections |
| Tube sizes | Ø 21.3 to 133 mm, wall thickness as designed |
| Bending radius | from 1.5 × tube diameter, cold-bent |
| Form | flat coil, helical coil, battery with header boxes |
| Connections | weld ends, flanges or header attachment to drawing |
| Materials | P235GH, P265GH, 16Mo3, 13CrMo4-5, 10CrMo9-10, stainless, heat-resisting |
| Testing | dimensional and visual inspection, pressure test, residual wall measurement at the bend |
| Surface | pickled, blasted or primed on request |
| Documentation | 3.1 or 3.2 certificate to EN 10204, dimensional and pressure 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
- Economisers in the flue gas pass of steam boilers
- Evaporator coils in heat recovery boilers
- Cooling coils in vessels, reactors and tanks
- Heating batteries in air drying and process air heating
- Heat recovery in industrial furnaces
- Replacement coils for outages and tube failures
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.
Pipe coils & heating batteries – frequently asked questions
What matters most when bending?
The residual wall at the outside of the bend. Cold bending thins the wall there, and that is exactly where the stress is highest. The drawing must therefore state the permissible minimum wall after bending, not only the starting wall.
How tight can the bending radius be?
Radii from 1.5 × tube diameter are usual. Tighter radii are possible but increase wall thinning at the outside of the bend and the ovality. For pressure-bearing coils the applicable code sets the limit.
What is the difference from a superheater coil?
Temperature. Superheater coils work in the creep range and need materials such as 13CrMo4-5 or P91. Coils for economisers, evaporators and batteries stay below that and usually manage with P235GH, P265GH or 16Mo3.
Is the coil supplied pressure tested?
On request, yes. A hydrostatic test with report is usual, and a leak test in addition where required. Scope and test pressure follow the applicable code and your specification.
What do you need for a quotation?
Drawing or isometric with radii and pitch, tube size and wall thickness, material grade, number of coils, type of connections and the required certificate to EN 10204.
Pipe coils & heating batteries – request a quote
Drawing, material and quantity are enough – we come back with price and lead time.