Vertical Patents (Class 122/155.1)
- Loop-type tube (Class 122/166.2)
- Central magazine (Class 122/168)
- Coil (Class 122/169)
- Contracted inlet (Class 122/171)
- Header (Class 122/172)
- Horizontal spur (Class 122/173)
- Internal fire tube (Class 122/174)
- Offset water firebox (Class 122/175)
- Transverse (Class 122/176)
- Vertical aligned fire tube (Class 122/178)
- Vertical spur (Class 122/181)
- Fluid fuel (Class 122/167)