22 Aug 2018

Since 1969, steam generators and thermal oil heaters have been manufactured in Cannon Bono Netro plant. The adjacent “Iron Museum” preserves the evidence of the ancient metallurgy traditions of the area.

Cannon Bono Netro is an industrial business specialised in manufacturing five types of steam generators and thermal oil heaters: UM and UM/HP instantaneous steam generators, FT fire tube boilers and OMV and OMP thermal oil heaters.

The steam generators range from 50 to 6,000 kg/h of steam and from 12 to 110 bar, while the oil heaters can generate from 200,000 to 10 million kcal/h. Some special much larger models are made to order for biomass cogeneration plants, designed and marketed by the subsidiary Cannon Bono Sistemi.

The production mix includes over 40 standard models in a vast range of customisable potentials and configurations. This significant diversification, both in terms of size and thermal technology, has led Cannon Bono Netro to organise specialised departments, in which the entire construction process is completed via verticalization, starting from steel sheets and tubes up to the finished, tested, functional product.


Most of the heaters and boilers manufactured at Netro use a thermal fluid recirculation system via coiling tubes. The steel tubes are bent into spirals so that they become cylindrical, with variable diameter and complexity depending on the model being built. The spirals can be single, double, or triple and the tube diameter can vary from 1 to 3 inches: all this requires the use of special tools that can ensure the tube is bent evenly (without constrictions or deformations), is perfectly circular, and the spirals are at maximum proximity.

Automatic tube bending machines and welding machines, that have been radically modified to make them suitable for the specific Netro production requirements, are used for this type of processing.

All the tube head-to-head welding is done automatically with cold wire TIG technology with Argon shielding gas. It is then x-rayed and tested with penetrating fluids and hydraulic pressure tests to ensure maximum seal over time and under harsh working conditions.

Highly qualified personnel make sure the inner coils fit perfectly into the outer ones, then insert them into the boiler body, and insulate with mineral wool and stainless steel.


In the Ingagna valley, located in the western Biella area, ironwork dates back to the Celtic population. Testimonies of the first family forges, dedicated to the production of agricultural tools, axes, cutlery and cutting weapons, are around 1232.

The industrial development of these activities began at the end of the nineteenth century, when dozens of forges were in operation. At that time the Officine Rubino were created, then bought, in 1969 by Bono Spa, today Cannon Bono Energia.

The Officine Rubino Iron Working Documentation Center is located inside the Cannon Bono Netro plant: organized on two floors, the museum, an example of industrial archeology annexed to a production reality still in operation, allows the observation of equipment and products, as well as drawings, samples, technical manuals that testify the evolution of metal processing systems.

For more information on the museum, visit cannon.com