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SG series
Fire tube steam boilers

A perfect wet back fire tube boiler for reducing energy consumption. Reliability, an advanced control system, energy efficiency and a low environmental impact are the key attributes that set this product as the market benchmark for the industrial boiler field. SG boilers are suitable for producing saturated and superheated steam and superheated water.

Key features

steam capacity

Steam capacity

2 – 30 t/h



12 – 25 barg



up to 97.5%


NOx emissions

80 mg/Nm³
(lower values on request)


H2 ready2OK

Reliability and durability due to many design solutions: tubes expanded and welded to the tube-sheets; tube-sheets with ledges to guarantee maximum quality of welding between sheet and tubes; the complete absence of refractory and tightening elements; a large volume of the furnace which reduces the formation of carbon deposits and pollution.

Combustion system suitable for different fuels: natural gas, biogas, GPL, hydrogen, diesel oil.

Simple and quick maintenance due to two-pass design with convenient access to the internal components of the boiler: furnace, inversion chamber, and tube plate.

High thermal efficiency due to efficient heat transfer, big exchange surfaces, and optimized heat recovery systems.

Multifunctional control system and dynamic monitoring of the boiler operation, ensuring optimal performance and safety even in offline mode.

Ability to fully integrate with Smart Factory complexes and other process control systems.

Low NOx emissions of less than 80 mg/m3 and lower emissions available on request according to BAT.

The SG boiler is a fire tube steam generator, two-pass wet back type with a horizontal design, fully packaged and complete with all the necessary control and safety devices.

SG steam generators have a complete shielding of the inversion chamber with a water tube enclosure. This, compared to other types of boilers, ensures fast access to the flue gas inversion chamber and complete visibility of the tubes, tube sheet, and combustion chamber.

SG series steam generators are manufactured and certified according to the European Directive PED. Other design codes and certifications can be applied, including ASME, SELO, etc., when considering the individual requirements of the customer.

After assembly, the boiler’s internal components are checked through non-destructive testing methods. At the end of the installation, our boilers are extensively fire-tested at our factory.

Compatible products


Our constant commitment to improve combustion efficiency and reduce pollutants released into the atmosphere has led us to develop high-performance burners that are able to:

  • Reduce NOx and CO2 emissions to handle Flue Gas Recirculating systems
  • Burn standard and special fuels (natural gas, hydrogen, biogas)
  • Ensure high flame stability
  • Guarantee wide turndown ratios

Our burners are designed and manufactured to perfectly combine with our own boilers’ combustion chamber geometry, optimizing thermal load regulation management.

Demineralization plant

Boiler water feeding requires low hardness concentration and conductivity to reduce the blow-down (heat loss). Two different types of treatment can be used: membrane-based technology and ionic-exchange solutions. Dedicated pre-treatments are necessary, based on the available water source.

Condensate treatment

It is necessary to purify the steam condensate from the process, to reduce water consumption and recover the heat contained in the condensate.

Dosing of chemical products

Oxygen scavengers are used as the protective dosage downstream of the thermo-physical degassers and as the alkalizing agents to maintain a high pH inside the boiler. The choice of proper water treatment represents the energy optimization of the steam generator/water treatment package and a source of savings in water extraction and discharge costs.


It is necessary to remove CO2 and O2 to prevent corrosion phenomena. There are two options available: conventional packages composed of a tower and a drum, or the compact “smart” unit where the degassing equipment is realized inside the drum. The performance range is 7-20 ppb, according to the type of the installed unit.

SG Series Fire Tube

Technical Data

SG Series 200 – 1000

SG 200SG 300SG 400SG 500SG 600SG 800SG 900SG 1000
Steam production [kg/h (up to)]200030004000500060008000900010000
Design pressure [barg]12 - 3012 - 3012 - 3012 - 3012 - 3012 - 2512 - 2512 - 25
Thermal efficiency [%]
*according to EN12953, higher efficiency
reachable with condensing systems on demand
90 - 97,5*90 - 97,5*90 - 97,5*90 - 97,5*90 - 97,5*90 - 97,5*90 - 97,5*90 - 97,5*
NOx emissions [mg/Nm3]
**@3% O2 for natural gas, depending on burner choice
(lower values on demand) at defined boundary conditions
90 - 97,5*90 - 97,5*90 - 97,5*90 - 97,5*90 - 97,5*90 - 97,5*90 - 97,5*90 - 97,5*
Length [mm]48006000630064007400795081008350
Height [mm]20002350235025503250325033003600
Width [mm]18002100210023002900290029003250

SG Series 1100 – 3000

SG 1100SG 1200SG 1400SG 1500SG 1800SG 2000SG 2200SG 2500SG 3000
Steam production [kg/h (up to)]110001200014000150001800020000220002500030000
Design pressure [barg]12 - 2512 - 2512 - 2512 - 2212 - 2212 - 2212 - 1912 - 1912 - 17
Thermal efficiency [%]
*according to EN12953, higher efficiency
reachable with condensing systems on demand
90* - 97,590* - 97,590* - 97,590* - 97,590* - 97,590* - 97,590* - 97,590* - 97,590* - 97,5
NOx emissions [mg/Nm3]
**@3% O2 for natural gas, depending on burner choice
(lower values on demand) at defined boundary conditions
< 60**< 60**< 60**< 60**< 60**< 60**< 60**< 60**< 60**
Length [mm]8500890091509400965010300110001200013000
Height [mm]360036003680375037503750390040004500
Width [mm]325033003300355036503800380038003900