Firetube Boilers

Firetube boilers are sometimes referred to as Scotch Marine Boilers due to their common use on ships in a horizontal configuration. Firetube boilers are very durable, easy to service, and work well with consistent and predictable loads. Firetube boiler characteristics include:

• 2, 3, and 4 pass configurations
• Design pressures from 15 psig to 300 psig
• Capacities up to 2,500 BoHP in a single boiler
• Can be used to produce steam or hot water
• Vertical firetube boilers – have a single pass and reduced capacities, under 150 BoHP
• Firebox boilers – offer reduced capacities, under 150 BoHP and pressures of 15 psig or less

Wet Back Water Tube Boilers

The wet back design has a water-cooled, rear face of the combustion chamber heating surface.

Benefits of the wet back design:

• Great heat transfer to the water
• Higher efficiency
• Lower maintenance costs
• Longer life expectancy
• Less stress on the rear tube sheets, prolonging the boiler life
• Less maintenance clearance required

Dry Back Water Tube Boilers

The dry back design has an open box rear combustion area, backed or surrounded by refractory. The benefits of the dry back design include:

• Lower first cost
• Simplistic design that is easier to service

Learn more about how wet back and dry back boilers compare.

Understanding State Specific Boiler Requirements

In certain areas of the country, there are state-specific laws regarding the design of boilers. Firetube manufacturers have adjusted their designs accordingly. For example, in Ohio there are restrictions on the amount of heating surface that can be used to run a boiler without an operator. A firetube boiler for such an application is commonly referred to as an “Ohio Special Boiler.” Recently, however, the laws in Ohio have changed to allow boilers that exceed the heating surface requirement to be run without an operator by providing some additional monitoring and documentation. 

Lathrop Trotter partners with Superior Boiler Works to offer their full line of firetube boilers. Our team has the expertise and experience to help customers throughout Ohio, Indiana, and Kentucky develop safe and compliant boiler applications.

Superior Firetube Boilers

Superior firetube boilers are designed for maximum efficiency, reliability, durability in the most demanding environments, dual fuel capable, and are available with NOx reduction technology to sub 9 ppm.  They offer:

• Apache 2-pass Dryback Firetube Boiler – sizes ranging from 10 to 2,400 BoHP
• Mohawk 3-pass Dryback Firetube Boiler – sizes ranging from 30 to 1,000 BoHP
• SX6 2-pass Wetback Firetube Boiler – sizes ranging from 100 to 2,500 BoHP
• Seminole 3-pass Wetback Firetube Boiler – sizes ranging from 70 to 2,400 BoHP
• Mohican 4-pass Wetback Firetube Boiler – sizes ranging from 50 to 1,500 BoHP
• Ohio Special – sizes ranging from 80 to 250 BoHP
• Triad Vertical Firetube Boiler – sizes ranging from 10 to 150 BoHP
• Arrowhead 3-pass Dryback Firebox Boiler – sizes ranging from 10 to 100 BoHP
• Osage 3-pass Wetback Firebox Boiler – sizes ranging from 10 to 100 BoHP
• Creek Condensing Hot Water Firetube Boiler– sizes ranging from 300 MBH to 6,000 MBH
• Ancillary Boiler Room Equipment
  • Deaerators (Spray, Tray, Dual Tank)
  • Feedwater Tanks
  • Condensate Return/Receivers
  • Blowdown Separators