Based out of Hutchinson Kansas, Superior Boiler, is the world’s leading manufacturer of Scotch Marine Firetube and high efficiency condensing boilers. As well as associated boiler room equipment for process steam, hot water, and waste recovery.

Getting to know Scotch Marine Fire Tube Boilers

The Scotch Marine Boiler is a firetube boiler, in that hot flue gases pass through tubes set within a tank of water. The general layout is that of a squat horizontal cylinder. One or more large cylindrical furnaces are in the lower part of the boiler shell. Above this is a large number of small-diameter fire-tubes. Gases and smoke from the furnace pass to the back of the boiler, then return through the small tubes and up and out of the chimney.

There are two basic designs for Scotch Marine Boilers. The typical design is the “wetback”, where the rear face of the combustion chamber is water-jacketed as a heating surface. The “dryback” variation has the rear of the combustion chamber as an open box, backed or surrounded only by a sheetmetal jacket. This simplifies construction, but also loses much efficiency.


2-Pass Dryback Firetube Boiler


2- Pass Dryback Boiler


3-Pass Dryback Firetube Boiler


4-Pass Wetback Firetube Boiler

Ohio Special

2 or 3-Pass Dryback or Wetback Firetube Boiler


3-Pass Wetback Firetube Boiler

Super Seminole

3-Pass Wetback Firetune Boiler


2-Pass Wetback Firetube Boiler

Getting to know Scotch Marine Water Tube Boilers

Superior Boiler manufacturer’s industrial watertube boilers in: Ds-Type, D-Type, O-Type, A-Type, & TSGU-Type.


TSGU – Tandem Steam generating Unit


Ds-Type Watertube Boiler


O-Type Watertube Boiler


Lamonth HTHW Generator


iHRSF – Heat Recovery Steam Generator


Multipass Steam & Hot Water Boiler


HRSG – Heat Recovery Steam Generator


D-Type Watertube Boiler


A-Type Watertube Boiler

Firebox Boiler

Superior Boiler has been manufacturing Firebox boilers in Hutchinson, Kansas since 1940. Over twenty thousand of our boilers have been shipped throughout the United states and to many foreign countries. Their superior performance is evidenced by the highest recommendation that can be given a product – the many customers who have purchased their second, third, tenth and even twentieth units. Superior Boiler, in conjunction with our network of independent sales and service organizations, forms an unbeatable team geared to meet your needs.


3-Pass Firebox Boiler


3-Pass Wetback Firebox Boiler

Vertical Boilers