XPlus Combustion Systems

The XPlus Combustion System is a new standard for boiler equipment upgrades. It fully integrates the burner with state of the art monitoring and controls. Throughout the entire development process, the burner design has included the requirement for repeatable, balanced and optimum fuel and air flow control. The result is a high quality burner that achieves and maintains overall fired equipment energy efficiency and low emissions. Most importantly, boiler owners are offered a single source for engineering, manufacturing and field commissioning responsibilities that is unrivaled in the industry.


Capacity – 40 MMBTUH – 150 MMBTUH

Fuel – Natural Gas, #2-#6 Oil, Specialty Fuels

NOx Levels – 30 PPM for Natural Gas

Turndown – 10:1 for Natural Gas; 8:1 for #2 oil

Recommended Boiler Type – Watertube

Recommended Uses (commercial or industrial) – Industrial

  • Overview
  • Application
  • Features
  • Documents

BurnerMate Universal Combustion Control: Fully metered combustion control strategy with oxygen trim and variable speed fan-based combustion air flow control is used. Any deviation from the required Oxygen set point resulting from changes in fuel stoichiometry, atmospheric conditions or boiler resistance, is automatically acknowledged and corrected, maintaining the highest fuel economy possible.

Low-Fire Fuel Changeover: Permits fuel transfer without requiring a burner shutdown and purge.

Enhanced Boiler Safety: Flue gas oxygen and temperature monitoring protects against excessive flue gas temperature and incomplete combustion.


Single Burner: Firetube / Watertube Boilers or HTHW Generators

Fuel: No. 2 through No. 6 and/or Natural Gas (consult factory for special or waste fuels)

Heat Input Ranges: 15 to 100 mmBtu/hr

NOx Emissions

Natural Gas: As low as 30 ppmc without FGR

No. 2 Fuel Oil: 100 ppmc (maximum 0.01% FBN) or less without FGR

No. 6 Fuel Oil: 300 ppmc (maximum 0.30% FBN) or less without FGR

Note: NOx performance is furnace geometry and heat release rate dependant.  Lower NOx emissions are attainable with the application of FGR. CO emissions are less than 100ppmc at all firing rates (exclusive of short circuiting).

Burner Efficiency
Any Fuel: 1.5 - 2.5% Excess O2, 50 - 100% Firing Rate (exclusive of “tramp” air)

Electrical: 80% KW Reduction, @ 40% Firing Rate

Turndown: 12:1 on gas firing; 10:1 on oil firing

Ramp Rate: 200% per minute

Back-Up Fuel: Oil or gas may serve as either the backup or supplemental fuel on simultaneous fuel firing applications

Supply Pressure 

Natural Gas: 2 - 5 psig (at Gas Manifold Inlet)

Fuel Oils: 75 - 110 psig (No. 2 through No. 6 at Atomizer Coupling Block inlet)

Atomizing Media: Nominally 20 psi higher than fuel oil pressure

Note: Consult factory for available pressures outside of the ranges given

Burner Control & Monitoring

Firing Rate:  BurnerMate Universal Fully Metered Combustion Control with Oxygen Trim and Variable Speed Fan Combustion Air Flow Control

Oxygen Sensor: Model “ZP” In-Situ Sensor, reliable zirconia oxide detector

Monitoring: SCADA/Flex Remote Monitoring and Control System

Controller: PCC-III Multiple Loop Controller

Instruments: Standard and optional equipment available


Low Emissions Design: Gas tube injectors and atomizer sprayer plate produce stable, staged, low temperature fuel and air combustion.

Stable Combustion: Center-fired gas, or very fine fuel oil droplets are ignited in the Stabilizing Combustion Zone. This feature produces outstanding flame stability during load changes and at very high excess air levels.

Energy Efficient: Low electrical consumption is obtained by variable speed fan control with a Variable Speed Drive (VSD). When required, pinpoint injection of Flue Gas Recirculation (FGR), via the FGR Injection Plenum achieves the required NOx emissions with reduced FGR flow. Variable speed FGR Fan control is used for additional energy reduction.

Exceptional Turndown: The combustion air plenum with inline characterized damper are dynamically modeled to assure exceptional turndown and balanced cross-sectional air flow.

No Refractory Maintenance: The burner throat is a high temperature metal. Custom refractory brick installation or maintenance are not required.

Free-Floating Design: Minimizes differential expansion imposed stresses.

Locked Design: No moving parts or adjustments necessary.

Recessed Plenum: Minimizes atomizer length and withdrawal clearance requirements.

Atomizer Coupling Block With Disengagement Safeties: Protects operating personnel from hot oil or steam discharges.

Integrated Primary Flow Elements: Integral combustion air, fuel gas and FGR measurements are used as the basis for combustion control. The integral FGR injection plenum allows independent measurement of combustion air and FGR flows.

Minimized “Hysteresis” Induced Control Errors: A direct-coupled damper / actuator is used. Damper linkage is not required.

Optimum Combustion Air Flow: VSD control of the FD Fan allows trimming of fan speed to exactly meet field conditions, thereby eliminating the need for fan over sizing, damper “short-stroking” or linkage adjustments.


XPlus Burner Specification

XPlus Burner Brochure

XPlus Burner Cutsheet