The Inspection hatch is made of a structure working as a fastening base for the manhole on the flue. It is made of two surfaces.
The inside surface can be removed and works as a thermal insulator by means of a 6 mm thick heat-insulating jacket, made of a glassy fibre ecology that can resist up to 1000° Celsius.
The outside surface, fixed to the structure, works as a water and air sealing surface by means of a NEOPRENE seal, locks the internal surface inside the structure by means of a mechanical clasp.
All the metal parts of the Inspection hatch are made of steel sp. 8/10 AISI 304 BA or copper: Cu DHP UNI 5649/1.