Notations:
1. Safety valve seat (DN25)
2. Hot water dumping (DN50)
3. Thermometer seat
4. Water level control branch pipe
5. Convective part
6. Furnace
7. Cast-iron furnace bar
8. Water supply pipe (DN50)
9. Plug
10. Air supply door
11. Ash door
12. Fuel door
13. Soot cleaning door
14. Smoke shutter
15. Manometer seat