NEC Areas of Expertise


Combustion & Combustion Systems Expertise

From unconventional fuels to modern safety systems we’ve done it all!

Norton Engineering’s highly experienced combustion systems & equipment subject matter experts (SMEs) assist clients in evaluating and maintaining existing heaters and boilers, energy efficiency improvements and safe operation. Our experience runs the gamut from traditional fired heaters and boilers, to those firing CO offgas from fluid catalytic cracking units and fluid coking units. Experience includes heaters using gas turbine exhaust as combustion air and high temperature methane and naphtha reformers used in hydrogen and ethylene production.

Our experience in refining and petrochemical plant operations affords us the ability to evaluate fired heater performance and safe operating limits from an operations perspective. We routinely evaluate the operation of client heaters and boilers to determine safe operating limits and set automatic trip points where safety instrumented systems are employed (SIS).

Norton has expertise in diagnosing heater and boiler operating problems ranging from the causes of catastrophic failures to combustion induced vibration. We have experience in safely demolishing heaters which have been destroyed by explosion and maximizing recovery of components which can be reused. We can evaluate components for reuse and design a new heater to replace the old while making maximum use of recoverable parts, to shorten the time needed for rebuilding while providing a robust and safe unit.

NEC Combustion Systems & Equipment expertise includes:

Fired Heaters

  • Grassroots, Proprietary, and Revamp Designs
  • New technology vetting and development
  • Troubleshooting tube failures, throughput limitations in atmospheric and vacuum unit heaters, run length extensions, diagnosis and correction of flow maldistribution problems, reducing wear in steam-air decoking operations, etc.
  • Identification of operating limits for tubes, burners and mechanical components, metallurgy upgrades, etc
  • Project Development: Evaluating heater problems to improve heater reliability and increase run lengths
  • Engineering and design services provided include: process, mechanical/equipment, process controls/instrumentation, structural analysis and design
  • NOx Control, reduction, and applications of Best Available Retrofit Control Technology (BARCT)
  • Advanced Process Controls
  • Safety Instrumented Systems (SIS)
  • Heater Safety
  • Tools and Computer Models


  • CO Boilers and Industrial Boiler revamps and retrofits: fuel switching, addition of solid fuel burning capability (petroleum coke) , revamp of coal fired stoker boiler to fire fuel oil and fuel gas, revamp of cold wall boilers to achieve NOx compliance, and revamp of natural circulation water tube boiler including feed water deaeration systems, combustion systems and controls.
  • Structural and mechanical modifications for boiler enhancements for increased backpressure due to addition of downstream equipment (SCR, scrubber, etc.).
  • Technology evaluations and inquiry packages for Low NOx Burner, Selective Catalytic Reduction (SCR), Selective Non-Catalytic Reduction (SNCR, ESNCR) and other NOx Control technologies.
  • Power Boilers and Reboilers: Modeling, Process Design, Equipment Addition and Rerating, Air Flow Modeling and Analysis. NOx reduction and fuel switching for existing coal-fired boilers.
  • Service Engineering/Troubleshooting
  • Capacity and Efficiency studies to improve boiler steam make and reduce energy consumption.
  • Reliability Improvements
  • Waste Heat Recovery (WHR) Units: Design and troubleshooting, unit revamps, fired and unfired systems, GTG flue gas, FCCU CO gas, fluid coker CO gas cooling. Designed replacement units GTG waste heat recovery, designed integral SCR units for GTG WHBs, revamped existing WHB units for FCCU SCR installations, designed grass roots WHBs for major refinery SCR projects, etc.


  • Operation and troubleshooting experience with raw gas, premixed, light and heavy oil, combination fuel burners including simultaneous dual fuel firing, and petroleum coke combustion systems
  • Low-NOx Burners and Ultra Low-NOx Burners: Experience in design of systems for retrofit of Low NOx burners in fired heaters, boilers, package boilers, incinerators, sulfur plant burners, etc. Experienced in grass roots designs utilizing Low and Ultra Low NOx burners. Experienced in revamp installations, startup, and testing of newly installed Low and Ultra Low NOx burner systems
  • Worked with a major ULNB supplier to modify standard designs to meet unique project specific limitations for refining client’s alkylation unit heaters
  • Burner Management Systems (BMS) and control systems for boiler operation: Troubleshooting burner control systems to upgrade boilers to newer technology Interpretation of API and NFPA regulation and best practices to cost effectively upgrade BMS systems.

Air Preheat Systems

  • Regenerative – Experience in design, operation, testing, and troubleshooting regenerative air preheaters. Initial set-up, sealing arrangements, onstream and off-line cleaning techniques, maintenance, etc.
  • Recuperative – Experienced in design, operation and troubleshooting of plate type preheaters (OCAP, BD, etc.) and tubular type air preheaters (e.g. Deka).

Fuel Supply

  • Refinery Fuel Gas Systems (RFG)– Experience in design, operation and troubleshooting of conventional RFG systems including integration with heater controls to ensure stable operation during periods of rapidly varying composition and heating value.
  • Low BTU Gas (LBG) Systems – Clean-up and distribution system design, operation and troubleshooting for Flexicoker LBG.
  • Oil Supply Systems – Experience in design, operation and troubleshooting of light and heavy fuel oil systems including fuel oil recirculation loops, heating systems, etc. Designed several VPS bottoms and DAO fuel oil systems.
  • Solid Fuel Supply Systems – Experienced in testing and implementing recommended fixes for coal pipe flow imbalances to optimize coal pulverizer and boiler operations.
  • Fuel Switching – Engineering and Designed systems for changing combustion fuel sources. Performed modeling, rerating and mechanical/structural reinforcement design for equipment fired different combustion sources. Engineered and specified burner management systems for new or modified fuel sources and burners.

Ancillary Systems

  • Forced & Induced Draft Fans
  • Burner Management Systems (BMS – Engineering, Design, Troubleshooting, Compliance)
  • Instrumentation and Controls for Combustion Systems (SIS)
  • Steam distribution systems
  • Fuel coalescing for reliability/efficiency improvements
  • Boiler feed water treatment, instrument air and utility feed systems
  • Instrumentation and Controls for Process Heating (process side control systems).
  • Assessment and Implementation of Maximum Achievable Control Technologies (MACT)
  • Assessment and Implementation of Best Achievable Retrofit Control Technologies (BARCT)
  • Emissions Control Systems for SOx, NOx, Particulate Matter
  • SCR, SNCR, ESP, Wet and Dry Scrubbers.
  • Flue Gas Recirculation (FGR), Induced Flue Gas Recirculation (IFGR) systems