Boiler tune-ups are a work practice standard that is required by law in the EPA Boiler MACT (maximum achievable control technology) rule. The rule requires that tune ups be performed every 2-5 years depending upon under which category the boiler falls. The following is a brief outline of the requirements for a boiler tune up.

Boiler MACT Tune Up Requirements:

  1. Inspect the burner, and clean or replace any components of the burner as necessary. This may be delayed until the next unit outage, but is not to exceed 36 months since the most recent inspection.
  2. Inspect the flame pattern and adjust the burner as necessary to optimize the flame pattern. The adjustment should be consistent with the manufacturer’s specifications or best engineering practices.
  3. Inspect the system controlling the air-to-fuel ratio and ensure that it is correctly calibrated and functioning properly. This may be delayed until the next unit outage, but is not to exceed 36 months since the most recent inspection.
  4. Optimize total emissions of CO. This optimization should be consistent with the manufacturer’s specifications or best engineering practices and with any nitrogen oxide requirement to which the unit is subject.
  5. Measure the concentrations in the effluent stream of CO in parts per million, by volume, and oxygen in volume percent before and after the adjustments are made.
  6. Maintain on-site and submit, if requested by the Administrator, a report containing the following information:
    1. Concentrations of CO in the effluent stream in parts per million, by volume, and oxygen in volume percent measured at high-fire or typical operating load before and after the tune-up of the boiler
    2. A description of any corrective actions taken as a part of the tune-up of the boiler
    3. The type and amount of fuel used over the 12 months prior to the tune-up of the boiler


Boiler MACT Energy Assessment:

All existing coal-fired, biomass-fired, or oil-fired boilers (units with heat input capacity of 10 MMBtu/hr and greater), not including limited-use boilers, must have a one-time Boiler MACT energy assessment completed. The energy assessment for the area sources as laid out in Boiler MACT is a qualitative analysis of the existing boiler system. The goal of the assessment is to ensure that the smaller area sources that are regulated by Boiler MACT are running as efficiently as possible and have sufficient modern technology to ensure efficient operation. Up to this point, these area source boilers have not been strictly regulated, and therefore this one-time assessment is to evaluate the efficiency of these boilers prior to the implementation of the Boiler MACT regulations. This assessment should simplify the process of compliance with Boiler MACT for area source boilers.


Boiler MACT Energy Assessment Requirements (Summarized):

  1. Visual inspection of the boiler system (i.e. cracks, corrosion, leaks, insulation)
    1. Boiler walk-down noting areas where excessive amounts of heat/steam are lost
    2. Effectiveness of any steam traps
    3. Ensure that no heat/steam is needlessly lost in any of the equipment
  2. Evaluation of operating characteristics of the affected boiler systems, specifications of energy use systems, operating and maintenance procedures, and unusual operating constraints
    1. Boiler system includes components such as feed water systems, combustion air systems, fuel systems (including burners), blowdown systems, combustion control systems, steam systems, and condensate return systems
    2. Review of plant data, specifically emissions, and steam and air temperature data
      1. Need to evaluate the efficiency of the turbine
      2. Determine areas where air flow/temperature adjustment would improve overall efficiency
      3. Evaluation of excess air
      4. Reduce blowdown frequency; plant may waste heat by blowing down before it’s necessary
      5. Ensure plant is recovering as much heat as possible from stack gases and hot condensate
    3. Discussion with engineers and operators to evaluate operating/maintenance procedures currently in place with emphasis on any unusual procedures and recurring issues
  3. Inventory of major systems consuming energy (i.e. energy use systems) from affected boiler(s) and which are under control of the boiler owner or operator
    1. Ensure all major consumers of energy generated from the boiler are operating efficiently
      1. Recommend ways to improve energy efficiency of major systems
    2. Major system defined by the following table:
  Boiler Annual Heat Input TBtu/yr (MW) Percent of Energy Consumption to be considered a Major System
  Less than 0.3 (10) At least 50%
  0.3 to 1 (10 to 33) At least 33%
  Greater than 1 (33) At least 20%

               c.  Reduction of steam pressure if possible

  1. Review of available architectural and engineering plans, facility operation and maintenance procedures and logs, and fuel usage
    1. Locate areas that are over-engineered or that have improper equipment that increases energy consumption
  2. List of major energy conservation measures that are within the facility’s control
  3. List of the energy savings potential of the energy conservation measures identified
    1. Estimate energy savings of each recommendation based on price of power saved
  1. Comprehensive report detailing the ways to improve efficiency, the cost of specific improvements, benefits, and the time for recouping those investments