• 770.777.2570

Thermal Fluid Heaters - In Stock!

Need a heater quick?  We have Hot Oil Heaters in stock. For sale or rent. Call (770) 777-2570 today!

Fire Tube Boilers - Two Pass Wet-Back

Product Code: SG, SG-PA, SG-ECO

Product Specifications

Capacity Range:

  • 425 to 1,761 BHP(4150 to 17,280 kW)

Steam Production:

  • 14,500 to 60,760 lb/hr (6,600 to 27,600 kg/hr)

Operating Pressures:

  • 174 to 435 psi (12 to 30 bar)

Fuel Option:

  • Natural Gas
  • #2 Fuel Oil/Diesel
  • Light Fuel Oils
  • LPG
  • Dual Fuel
  • Additional Fuel Options Available


  • Horizontal

Two Pass, Wet Back Design

Combustion Air Preheater Optional

  • Model SM-PA

Economizer Optional

  • Model SM-ECO 

Fire Tube Boilers - Two Pass Wet-Back

Product Description

The SG Fire Tube Boilers are our direct fired two pass wet back boilers. The burner fires down the center of the fire tube, which is located on the lower half of the boiler. The flame travels down the fire tube and enters the inversion chamber. The exhaust gases then travel from the inversion chamber through the combustion tubes and exit the boiler through the exhaust stack. The wet back design refers to water at the back of the boilers inversion chamber.

The SG Fire Tube Boilers are only available in a two pass design. A two pass design has a more balanced heat transfer from the tube to the water than a three pass design. The optimized heat transfer lessens the thermal stresses on the structure and helps mitigate cracking or deformation. In addition, the third pass of a three pass boiler has negligible heat transfer and has to potential to expose the tubes to corrosion (dew point).

The SG has the opportunity to be supplied with a variety of forced draft burners, provided by some of the world’s leading burner manufactures. This allows us to utilize a variety of fuels, meet stringent emissions requirements and even allow our customers the opportunity to select the burner of their choice.

The SG-PA is our high efficiency option of the SG Fire Tube Boiler. The SG-PA is constructed in a horizontal orientation and is supplied with a combustion air preheater at the burner side of the heater.

The SG-ECO is our feed water preheater option of the SG Fire Tube Boiler. The feed water preheater utilizes and economizer to preheat the water entering the steam generator. This in turn, enables the customer to obtain optimum performance of the generator by supplying the necessary feed water temperatures to the Fire Tube Boiler.

The SG, SG-PA and SG-ECO Fire Tube Boilers are designed and constructed to various local code requirements around the world. The most common codes are ASME with National Board registration for the United States, CRN for Canada and CE/PED/TUV/DIN for Europe. Additional code requirements may be met if necessary.

Package and containerized systems are available for both the SG, SG-PA, and SG-ECO Fire Tube Boilers. These package systems can be customized to meet each of our customers’ needs, including but not limited to: control panel, feed water pumps, feed water treatment, deaerator, feed water tanks, ladders and platforms and ancillary components. These auxiliary components are typically fabricated in the USA for USA/Canada installations.





Fire Tube Boilers In General

Fire tube boilers are a form of large water content boilers used to provide customers with steam as a heat transfer media. Typically, the quality of steam provided by these units are much higher than forced circulation steam generators. The higher quality of steam mitigates the use of steam separators or steam accumulators.