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4-PASS STEAM BOILER

FOUR steam generation for projects that value fuel economy, stable flame, and quiet operation.

Designed and manufactured by Steammaster, FOUR combines the only Brazilian 4-pass fire-tube architecture in its class with axial diffuser burner technology, low-NOx operation, and full electronic boiler management to deliver efficient steam with a refined operating profile.

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FOUR 4-pass steam boiler product visual
FOUR product reference image FOUR installation reference image FOUR burner-side detail FOUR engineering detail
Oil and Gas 4 Gas Passes

Why engineering teams specify FOUR

FOUR was developed for projects that need strong thermal use, stable combustion, and low emissions in a robust fire-tube package with quiet operation and practical field serviceability.

  • Steam generation range from 3,000 to 20,000 kg/h with working pressure up to 21 bar.
  • High-efficiency fire-tube design with 4 gas passes for better fuel economy and stronger thermal recovery.
  • Axial diffuser burner with factory low-NOx technology for NOx below 70 ppm without flue gas recirculation.
  • UL and CE certified flame and boiler controls with full electronic management for all key operating variables.

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Interactive 3D

Interactive FOUR package review

Use this model to review the 4-pass arrangement, service corridors, and package footprint before moving into detailed project definition.

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Where FOUR fits best

Projects focused on lower fuel use

The 4-pass architecture is attractive when the project is looking for a more efficient fire-tube route with better thermal recovery.

Plants that value quiet and smooth operation

The axial diffuser burner contributes to stable flame behavior with lower vibration and a more comfortable operating environment.

Industrial sites asking for low-NOx without extra complexity

FOUR is useful when emissions matter, but the team wants to avoid unnecessary recirculation packages and keep the solution cleaner to operate.

Teams comparing efficiency against standard packages

FOUR deserves attention when the project is not only comparing nameplate capacity, but also looking at fuel cost and operational refinement over time.

Benefits

Fuel economy from 4-pass architecture

The 4-pass gas path improves thermal use and helps convert more fuel energy into useful steam production over the operating envelope.

Stable, quiet, low-vibration burner behavior

The axial diffuser burner was selected to improve flame stability and make field operation quieter and smoother.

Low NOx without added recirculation complexity

Factory low-NOx burner technology keeps emissions below 70 ppm without relying on extra flue gas recirculation packages.

Full electronic boiler management

The control system manages combustion and boiler variables with certified components prepared for repeatable industrial operation.

Project and procurement notes

FOUR becomes easier to position when the discussion includes fuel strategy, load profile, emissions expectations, and the value of quieter and smoother field operation.

  • Useful when lifecycle operating cost matters as much as first purchase.
  • A strong comparison candidate for teams balancing efficiency, emissions, and field behavior.

Downloads and decision support

Use Steammaster engineering support to compare FOUR against other fire-tube arrangements and understand where 4-pass architecture creates practical value for the project.

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Technical details

Steam capacity3,000 to 20,000 kg/h
Pressure rangeUp to 21 bar
Combustion layoutSingle furnace, axial diffuser burner, 4 gas passes
EmissionsLow NOx below 70 ppm without FGR
Control packageUL and CE certified flame and boiler controller
Capacity referenceSteam output rated with 20 C feedwater
FOUR industrial steam boiler installation view