| 1/00 |
Feed-water heaters, e.g. preheaters |
| 1/02 |
Feed-water heaters, e.g. preheaters with water tubes arranged in the boiler furnace, fire tubes, or flue ways (heat-exchange tubes in general F28F) |
| 1/04 |
Feed-water heaters, e.g. preheaters with water tubes arranged in the boiler furnace, fire tubes, or flue ways (heat-exchange tubes in general F28F) the tubes having plain outer surfaces, e.g. in vertical arrangement |
| 1/06 |
Feed-water heaters, e.g. preheaters with water tubes arranged in the boiler furnace, fire tubes, or flue ways (heat-exchange tubes in general F28F) the tubes having plain outer surfaces, e.g. in vertical arrangement in horizontal arrangement |
| 1/08 |
Feed-water heaters, e.g. preheaters with water tubes arranged in the boiler furnace, fire tubes, or flue ways (heat-exchange tubes in general F28F) the tubes having fins, ribs, gills, corrugations, or the like on their outer surfaces, e.g. in vertical arrangement |
