Composite tube for boilers
Composite tube (compound tube) suitable for applications where the conditions outside and inside the tube require material properties that cannot be met by one material only.
The composite tube consists of two different alloys metallurgically bonded together to achieve good thermal transfer properties. One alloy is used to withstand corrosion, while the other often is an approved pressure vessel material.
Typical applications for Sandvik composite tubes are steam boilers with corrosive condtions, such as:
- Black liquor recovery boilers (BLRB)
- Syngas coolers
- Waste heat boilers
- Waste-to-energy boilers
Sandvik composite tube have been installed in more than 400 boiler units worldwide since the 1970s. Contact us for references.
| Sandvik grade | UNS | ASTM/ ASME |
EN no. | EN name |
|---|---|---|---|---|
| Corrosion resistant alloy | ||||
| Sanicro 67 | N06690 | - | 2.4642 | - |
| Sanicro 38 | N08825 Mod. | - | 2.4858 | - |
| Sanicro 30 | N08800 | - | 1.4558 | - |
| Sanicro 28 | N08028 | - | 1.4563 | X1NiCrMoCu31-27-4 |
| Sandvik 3RE28 | - | 310 | 1.4845* | - |
| Sandvik 3R12 | S30403/ S30400 |
304L | 1.4306 | - |
| Load carrying alloy | ||||
| 4L7 | - | SA210-A1 | 1.0405 | ST45.8/lll |
| 3Mo1 | - | - | 1.5415 | 16Mo3 |
| HT5 | - | SA213-T12 | 1.7335 | 13CrMo4-5 |
| HT8 | - | SA213-T22 | 1.7380 | 10CrMo910 |
| HT7 | - | SA213-T91 | 1.4903 | X10CrMoVNb91 |
* According to EN 10095, valid for heat resistant grades in the form of sheet/plate, strip, semi-finished products, bar, rod and sections (not for pressure or creep purposes).
| Outside diameter | Total minimum wall thickness |
Thickness outer layer |
Minimum thickness inner layer |
||||
|---|---|---|---|---|---|---|---|
| mm | in. | mm | in. | mm | in. | mm | in. |
| 38.0 | 1 1/2 | 5.00 | 0.197 | 1.30 | 0.051 | 3.70 | 0.146 |
| 50.8 | 2 | 5.08 | 0.200 | 1.50 | 0.059 | 3.58 | 0.141 |
| 63.5 | 2 1/2 | 6.53 | 0.257 | 1.65 | 0.065 | 4.88 | 0.192 |
| 76.2 | 3 | 6.58 | 0.259 | 1.65 | 0.065 | 4.93 | 0.194 |
Related information
Downloads
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Sanicro 67/4L7 composite tubes for black liquor recovery boilers
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Sandvik 3R12/4L7 composite tubes for black liquor recovery boilers
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Sanicro 38/4L7 composite tubes for black liquor recovery boilers
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Sanicro 28 composite tubes for steam boilers
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Sandvik 310/T22 composite tubes for superheaters
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Sandvik HT5/Sanicro 30 composite tubes for syngas coolers
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