The Osby GTP is a 3-pass firing tube boiler with cylindrical furnace and convection part in the shape of gas throughflow tubes in two passes without turbulators. The boiler is a welded steel boiler available in horizontal as well as vertical installations. The furnace, turning chamber and tubes are completely water-cooled. The boiler is self-circulating, which provides an even water temperature throughout the boiler.

Osby GTP is mainly intended for oil or gas firing.The boiler is insulated using 100 mm mineral wool covered with corrosion-protected enamelled steel plating.

Mechanical cleaning is carried out from the front, via a large insulated front door. Cleaning during operation can be carried out using steam, pressure air or sound.