Each set of tubes that hot combustion flue gas travels through before making a turn within the boiler, is considered a "pass." A 3-pass firetube boiler design consists of three sets of horizontal tubes, with the stack outlet located on the rear of the boiler. A downdraft design keeps the cooler water from having an effect on the hot surfaces within the boiler.
Generally speaking, a boiler with more passes provides more opportunities for hot gasses to transfer heat to the water in a boiler and operate more efficiently, however, boiler efficiency is highly affected by tube design, and not simply the number of passes. It is possible for a 3-pass boiler with a tube design (such as XID boiler tubes) that allows more heat transfer time to deliver the same or higher efficiency rating than a 4-pass boiler with standard tubes.
3 pass firetube boilers offer:
- maximized heat transfer
- minimal refractory
- high steam/water storage
- effective handling of wide load demands
Trust the firetube boiler experts at IB&M
Industrial Boiler & Mechanical proudly sells new 3 pass firetube boilers from Johnston Boiler Company, but also has the expertise to provide on-site or in-house service and repair for 3 pass boilers from other manufacturers as well.
In addition to an in-stock inventory of used 3 pass boilers, we offer firetube boiler customization to meet any specification. Firetube boilers can be shipped individually, on a packaged skid, or as complete "boiler in a box" solution. And as as a fully licensed General Contractor with divisions dedicated to every aspect of the boiler room inside and out, we are able to provide system design and engineering, concrete work, electrical services, process piping, and more to provide a total steam plant solution.
If you are considering the purchase of a new or used 3 pass firetube boiler, need equipment maintenance or have an emergency rental situation, contact IB&M today at (855) 753-BOILER.