1146-1 (Adopted September 9, 1988)(Amended January 6, 1989 ) (Amended May 13, 1994)(Amended June 16, 2000) (Amended November 17, 2000)(Amended September 5, 20 08)

RULE 1146 EMISSIONS OF OXIDES OF NITROGEN FROM

INDUSTRIAL, INSTITUTIONAL, AND COMMERCIAL BOILERS, STEAM GENERATORS, AND PROCESS HEATERS

(a) Applicability This rule applies to boilers, steam generators, and process heaters of equal to or greater than 5 million Btu per hour rated heat inpu t capacity used in all industrial, institutional, and commercial operations with the e xception of: (1) boilers used by electric utilities to generate electricity; and (2) boilers and process heaters with a rated heat i nput capacity greater than 40 million Btu per hour that are used in petroleum ref ineries; and (3) sulfur plant reaction boilers.

(b) Definitions (1) ANNUAL CAPACITY FACTOR means the ratio of the a mount of fuel burned by a unit in a calendar year to the amount o f fuel it could have burned if it had operated at the rated heat input c apacity for 100 percent of the time during the calendar year. (2) ANNUAL HEAT INPUT means the actual amount of he at released by fuels burned in a unit during a calendar year. (3) ATMOSPHERIC UNIT means any natural gas fired un it with a heat input less than or equal to 10 million Btu per hour with a non-sealed combustion
chamber in which natural draft is used to exhaust c ombustion gases. (4) BOILER or STEAM GENERATOR means any combustion equipment fired with liquid and/or gaseous (including landfil l and digester gas) and/or solid fossil fuel and used to produce steam or to h eat water and that is not used exclusively to produce electricity for sale. Boiler or Steam Generator does not include any waste heat recovery boiler tha t is used to recover
sensible heat from the exhaust of a combustion turb ine or any unfired waste heat recovery boiler that is used to recover sensible heat from the exhaust of any combustion equipment. (5) BTU means British thermal unit.Rule 1146 (Cont.) (Amended September 5, 2008)

1146-2 (6) GROUP I UNIT means any unit burning natural gas with a rated heat input greater than or equal to 75 million Btu per hour, e xcluding thermal fluid
heaters. (7) GROUP II UNIT means any unit burning gaseous fu els, excluding digester and landfill gases, with a rated heat input less th an 75 million Btu per hour down to and including 20 million Btu per hour, excl uding thermal fluid
heaters. (8) GROUP III UNIT means any unit burning gaseous f uels, excluding digester and landfill gases, and thermal fluid heat ers with a rated heat input less than 20 million Btu per hour down to and including 5 million Btu per hour, and all units operated at schools and universities greater than or equal to 5 million Btu per hour. (9) HEALTH FACILITY has the same meaning as defined in Section 1250 of the California Health and Safety Code. (10) HEAT INPUT means the chemical heat released du e to fuel combustion in a unit, using the higher heating value of the fuel. This does not include the sensible heat of incoming combustion air. (11) NOx EMISSIONS means the sum of nitric oxide an d nitrogen dioxide in the flue gas, collectively expressed as nitrogen di oxide. (12) PROCESS HEATER means any combustion equipment fired with liquid and/or gaseous (including landfill and digester gas ) and/or solid fossil fuel and which transfers heat from combustion gases to w ater or process streams. Process Heater does not include any kiln or oven used for drying, curing, baking, cooking, calcining, or vitrifying; or any unfired waste heat recovery heater that is used to recover sensible he at from the exhaust of any combustion equipment. (13) RATED HEAT INPUT CAPACITY means the heat input capacity specified on the nameplate of the combustion unit. If the combustion unit
has been altered or modified such that its maximum heat input is different than the heat input capacity specified on the namep late, the new maximum heat input shall be considered as the rated heat in put capacity. (14) SCHOOL means any public or private school, inc luding juvenile detention facilities with classrooms, used for purposes of th e education of more than 12 children at the school, including in kindergarte n and grades 1 to 12, inclusive, but does not include any private school in which education is primarily conducted in private homes. The term inc ludes any building orRule 1146 (Cont.) (Amended September 5, 2008)

1146-3 structure, playground, athletic field, or other are a of school property, but does not include unimproved school property. (15) STANDBY BOILER is a boiler which operates as a temporary replacement for primary steam or hot water while th e primary steam or hot water supply unit is out-of-service. (16) THERM means 100,000 Btu. (17) THERMAL FLUID HEATER means a PROCESS HEATER in which a process is heated indirectly by a heated fluid othe r than water. (18) UNIT means any boiler, steam generator, or pro cess heater as defined in paragraph (b)(4) or (b)(12) of this subdivision.

(c) Requirements (1) The owner or operator shall subject all of the units within the facility to the NOx emission limits and schedules specified in Tabl e 1146-1:



### Table 1146-1 – Standard Compliance Limits and Sched ule

Rule Reference Category Limit Submit Compliance Plan on or before Submit Application

for Permit to Construct on or before Unit Shall be in

Full Compliance on or before

(c)(1)(A) All Units Fired on

Gaseous Fuels 30 ppm or

for natural gas fired units 0.036 lbs/10 6 Btu - - September 5, 2008

(c)(1)(B) Any Units Fired on

Non-gaseous Fuels 40 ppm - - September 5, 2008

(c)(1)(C) Any Units Fired on

Landfill Gas 25 ppm - - January 1, 2015

(c)(1)(D) Any Units Fired on

Digester Gas 15 ppm - - January 1, 2015

(c)(1)(E) Atmospheric Units 12 ppm or 0.015 lbs/10 6 Btu January 1, 2010 January 1, 2013 January 1, 2014Rule 1146 (Cont.) (Amended September 5, 2008)

1146-4 

### Table 1146-1 – Standard Compliance Limits and Sched ule (continued)

(2) In lieu of complying with the NOx emission limits a nd schedules specified in paragraph (c)(1), the owner or operator may elec t to subject all of the units within the facility to the requirements speci fied in Table 1146-2. The owner or operator that fails to submit a Compli ance Plan or Application for Permit to Construct pursuant to the schedule specified in Table 1146-1 for any of the Group II units shall be subject to the NOx limits and schedule specified in Table 1146-2.



### Table 1146-2 – Enhanced Compliance Limits and Sched ule

Rule Reference Category Limit Submit Compliance Plan on or before Submit Application for Permit to Construct on or before Unit Shall be

in Full Compliance on or before (c)(2)(A) Group II Units

75% or more of units (by heat input) January 1, 2011 January 1, 2013 January 1, 2014

(c)(2)(B) Group II Units

100% of units (by heat input) 5 ppm or 0.0062 lbs/10 6 Btu January 1, 2011 January 1, 2015 January 1, 2016 Rule Reference Category Limit Submit Compliance Plan on or before Submit Application

for Permit to Construct on or before Unit Shall be in

Full Compliance on or before
(c)(1)(F) Group I Units 5 ppm or 0.0062 lbs/10 6
Btu - January 1, 2012 January 1, 2013

(c)(1)(G) Group II Units

75% or more of units (by heat input) January 1, 2010 January 1, 2011 January 1, 2012

(c)(1)(H) Group II Units

100% of units (by heat input) 9 ppm or January 1, 2010 January 1, 2013 January 1, 2014

(c)(1)(I) Group III Units

75% or more of units (by heat input) January 1, 2011 January 1, 2012 January 1, 2013

(c)(1)(J) Group III Units

100% of units (by heat input) 0.011 lbs/10 6 Btu

January 1, 2011 January 1, 2014 January 1, 2015Rule 1146 (Cont.) (Amended September 5, 2008)

1146-5 (3) For dual fuel co-fired combustion a weighted av erage limit calculated by Equation 1146-1 may be used provided a totalizing f uel flow meter is installed pursuant to paragraph (c)(8), for units b urning a combination of
both fuels.

(CL A x Q A ) + (CL B x Q B ) Weighted Limit

= ______________________ Equation 1146-1

Q A + Q B

Where:
CL A

= compliance limit for fuel A
CL B = compliance limit for fuel B Q A = heat input from fuel A Q B = heat input from fuel B

(4) The owner or operator of any unit(s) with a hea t input capacity greater than or equal to 5 million Btu per hour shall not discha rge into the atmosphere carbon monoxide (CO) emissions in excess of 400 ppm or for natural gas

fired units 0.30 lbs/10 6 Btu.
(5) In lieu of complying with the applicable emissi on limits specified in paragraphs (c)(1), (c)(2), and (c)(3), the owner or operator of any unit(s) in operation prior to September 5, 2008 with an annual heat input less than or equal to 9.0 x 10 9 Btu (90,000 therms) per year, shall: (A) operate the unit(s) in a manner that maintains stack gas oxygen concentrations at less than or equal to 3 percent o n a dry basis for any 15-consecutive-minute averaging period; or (B) tune the unit(s) at least twice per year, (at i ntervals from 4 to 8 months apart) in accordance with the procedure desc ribed in Attachment 1 or the unit manufacturer's specified t une-up procedure. If a different tune-up procedure from t hat described in Attachment 1 is used then a copy of this procedure shall be kept on site. The operator of any unit(s) selecting the tu ne-up option shall maintain records for a rolling twenty four month pe riod verifyingRule 1146 (Cont.) (Amended September 5, 2008)

1146-6 that the required tune-ups have been performed. If the unit does not operate throughout a continuous six-month perio d within a twelve month period, only one tuneup is required fo r the twelve month period that includes the entire period of non -operation. For this case, the tune-up shall be conducted within th irty (30) days of start-up. No tune-up is required during a rolling twelve month period for any unit that is not operated during tha t rolling twelve month period; this unit may be test fired to verify availability of the unit for its intended use but once the test firing is completed the unit shall be shutdown. Records of test firings sha ll be maintained for a rolling twenty four month period, and shall b e made accessible to an authorized District representative upon request. (6) Any unit(s) with a rated heat input capacity gr eater than or equal to 40 million Btu per hour and an annual heat input great er than 200 x 10 9 Btu per year shall have a continuous in-stack nitrogen oxides monitor or equivalent verification system in compliance with 4 0 CFR part 60 Appendix B Specification 2. Maintenance and emissi on records shall be maintained and made accessible for a period of two years to the Executive
Officer. (7) An owner or operator that has installed or mod ified a Group III natural gas fired unit prior to (September 5, 2008) complying w ith the applicable BACT emission limit of 12 ppm or less of NOx may de fer compliance with subparagraphs (c)(1)(I) or (c)(1)(J) until the unit’s burner(s) replacement. (8) Any owner or operator who chooses the pound per mil lion Btu compliance option specified in paragraph(s) (c)(1) (c)(2), or (c)(4) or chooses the weighted average emission limit using Equation 1146 -1 under paragraph (c)(3) shall install a non-resettable totalizing fu el meter to measure the total of each fuel used by each individual unit, as approved by the
Executive Officer. (9) The owner or operator of Group II or III units shall submit for the approval of the Executive Officer a compliance plan in accor dance with the requirements of Rule 221 – Plans and Rule 306 – Pla n Fees by the applicable date specified in Tables 1146-1 or 1146- 2. The compliance plan shall include the following information:Rule 1146 (Cont.) (Amended September 5, 2008)

1146-7 (A) Owner/operator contact information (company nam e, AQMD facility identification number, contact name, phone number, address, e-mail address). (B) Number and size (mmbtu/hr) of Group II and III units located at the facility. (C) Selection of the Standard (Table 1146-1) or Enh anced (Table 1146-2) compliance schedule by Group II and III uni ts. (D) The owner or operator of more than one unit loc ated within the same facility that have opted to divide the units b y heat input for the purpose of separate compliance dates according to Tables
1146-1 or 1146-2 shall indicate which units are cat egorized 75 percent or more of the heat input and which units m ake up the remaining 100 percent of the heat input. (10) On or after January 1, 2015, an owner operator of any landfill or digester gas (biogas) unit co-fired with natural gas shall n ot operate the unit in a
manner that exceeds the emission concentration limi ts specified in subparagraphs (c)(1)(C) or (c)(1)(D), provided that the facility monthly average biogas usage by the biogas units is 90% or more, based on the higher heating value of the fuels used. (A) The Executive Officer may approve the burning o f more than

10% up to: (i) 25% natural gas in a biogas fired unit at the 1 5 ppm (digester gas) or 25 ppm (landfill gas) NOx level, when it is necessary, if the only alternative to limiting n atural gas to 10% would be shutting down the unit and flaring more biogas. (ii) 50% natural gas in a digester gas-fired unit a t the 15 ppm NOx level, when it is necessary as specified in cla use (c) (10)(A)(i) and for units installed on or after Sept ember 5, 2008 provided the unit has demonstrated compliance with the NOx limits in paragraph (c)(1) applicable to un its fired exclusively on natural gas. For units subject to this subparagraph, the percent natural gas usage shall be based on the facility monthly averag e biogas usage by the biogas units and the higher heating va lue of the
fuels used.Rule 1146 (Cont.) (Amended September 5, 2008)

1146-8 (B) Any biogas-fired unit burning more than the app roved percent

natural gas as determined under subparagraph (c)(10 )(A) shall comply with the weighted average NOx limit specifie d in paragraph (c)(3).

(d) Compliance Determination (1) An owner or operator of any unit(s) shall have the option of complying with either the pound per million Btu or parts per million emission limits specified in paragraphs (c)(1), (c)(2), (c)(3), and (c)(4). (2) All emission determinations shall be made in th e as-found operating condition, except no compliance determination shall be established during start-up, shutdown, or under breakdown conditions. Compliance determination as specified in paragraph (d)(6) shal l be conducted at least 250 operating hours, or at least thirty days subseq uent to the tuning or servicing of any unit, unless it is an unscheduled repair. (3) All parts per million emission limits specified in subdivision (c) are referenced at 3 percent volume stack gas oxygen on a dry basis averaged over a period of 15 consecutive minutes. (4) Compliance with the NO x and CO emission requirements of paragraphs (c)(1), (c)(2), (c)(3), and (c)(4) and the stack-g as oxygen concentration requirement of subparagraph (c)(5)(A) shall be dete rmined using a District approved contractor under the Laboratory Approval P rogram according to the following procedures: (A) District Source Test Method 100.1 - Instrument al Analyzer

Procedures for Continuous Gaseous Emission Sampling (March 1989), or (B) District Source Test Method 7.1 - Determinatio n of Nitrogen

Oxide Emissions from Stationary Sources (March 1989 ) and
District Source Test Method 10.1 - Carbon Monoxide and Carbon Dioxide by Gas Chromatograph/Non-Dispersive Infrare d Detector (GC/NDIR) - Oxygen by Gas Chromatograph-Thermal Conductivity (GC/TCD) (March 1989); or (C) United States Environmental Protection Agency Conditional Test

Method CTM-030, Determination of Nitrogen Oxides, C arbon Monoxide, and Oxygen Emissions from Natural Gas-Fir ed Engines, Boilers and Process Heaters Using Portable Analyzers; orRule 1146 (Cont.) (Amended September 5, 2008)

1146-9 (D) ASTM D6522-00(2005) Standard Test Method for De termination of Nitrogen Oxides, Carbon Monoxide, and Oxygen
Concentrations in Emissions from Natural Gas-Fired Reciprocating Engines, Combustion Turbines, Boilers, and Process Heaters Using Portable Analyzers (E) any other test method determined to be alterna tive and approved before the test in writing by the Executive Officer s of the District and the California Air Resources Board and the Regi onal
Administrator of the United States Environmental Pr otection Agency, Region IX; or (F) a continuous in-stack nitrogen oxide monitor o r equivalent verification system as specified in paragraph (c)(6 ).
Records of all source tests shall be made availabl e to District personnel upon request. Emissions determined to exceed any l imits established by this rule through the use of any of the above-refer enced test methods shall
constitute a violation of this rule. (5) For any operator who chooses the pound per million Btu of heat input compliance option of paragraph (c)(1), (c)(2), (c)( 3), or (c)(4), NO x emissions in pounds per million Btu of heat input s hall be calculated using procedures in 40 CFR Part 60, Appendix A, Method 19 , Sections 2 and 3 and CO emissions in pounds per million Btu of heat input shall be calculated according to the Protocol for the Period ic Monitoring of Nitrogen Oxides, Carbon Monoxide, and Oxygen from U nits Subject to South Coast Air Quality Management District Rules 1 146 and 1146.1. (6) Compliance determination with the NOx emission requ irements in paragraph (d)(4) shall be conducted once: (A) every three years for units with a rated heat input greater than or equal to 10 million Btu per hour, except for units subject to paragraph (c)(6). (B) every five years for units with a rated heat input less than 10 million Btu per hour down to and including 5 millio n Btu per hour. (7) Provided the emissions test is conducted within the same calendar year as the test required in paragraph (d)(6), an owner or operator may use the following emissions tests to comply with paragraph (d)(6): (A) Periodic monitoring or testing of a unit as require d in a Title V permit pursuant to Regulation XXX, orRule 1146 (Cont.) (Amended September 5, 2008)

1146-10 (B) Relative accuracy testing for continuous emissions monitoring verification pursuant to Rule 218.1 or 40 CFR part 60 Appendix B Specification 2. (8) Any owner or operator of units subject to this rule shall check NOx emissions with a portable NOx, CO and oxygen analyz er according to the Protocol for the Periodic Monitoring of Nitrogen Ox ides, Carbon Monoxide, and Oxygen from Units Subject to South Co ast Air Quality Management District Rules 1146 and 1146.1 according to the following
schedule: (A) On or after July 1, 2009, the owner or operator of units subject to paragraphs (c)(1), (c)(2), (c)(3), and (c)(4) shall check NOx emissions at least monthly or every 750 unit operat ing hours, whichever occurs later. If a unit is in compliance for three consecutive emission checks, without any adjustment s to the oxygen sensor set points, then the unit may be chec ked quarterly or every 2,000 unit operating hours, whichever occurs later, until there is an emission check indicating noncompliance

. (B) On or after January 1, 2015 or during burner replac ement, whichever occurs later, the owner or operator of un its subject to paragraph (c)(5) shall check NOx emissions accordin g to the tuneup schedule specified in subparagraph (c)(5)(B). (C) Records of all monitoring data required under subpa ragraphs (d)(8)(A) and (d)(8)(B) shall be maintained for a r olling twelve month period of two years (5 years for Title V faci lities) and shall be made available to District personnel upon reques t. An owner or operator shall not be considered in violation of th e emissions limits of this rule or in permit conditions if the owner o r operator complies with requirements specified in paragraph ( d)(10). Any emission check conducted by District staff that fin ds excess
emissions is a violation. (D) The portable analyzer tests required under subp aragraph (d)(8)(A) and (d)(8)(B) shall only be conducted by a person w ho has completed an appropriate District-approved training program in the operation of portable analyzers and has received a certification issued by the District.Rule 1146 (Cont.) (Amended September 5, 2008)

1146-11 (9) An owner or operator shall opt to comply with t he requirements as applied to CO emissions specified in paragraph (d)(8) or su bparagraph: (A) (d)(6)(A) for units greater than or equal to 1 0 mmbtu/hr, or (B) (d)(6)(B) for units less than 10 mmbtu/hr. (10) A source test specified under paragraph (d)(6) or an emission check conducted under the requirements specified in parag raph (d)(8) that finds emissions in excess of those allowed by this rule o r a permit condition
shall not constitute a violation of this rule if th e owner or operator corrects the problem and demonstrate compliance with another source test or
emission check within 72 hours from the time the ow ner or operator knew of excess emissions, or reasonably should have know n, or shut down the unit by the end of an operating cycle, whichever is sooner. (11) An owner or operator may opt to lower the unit ’s rated heat input capacity. The lowered rated heat input capacity shall not be less than 2 million Btu per hour and shall be based on manufacturer’s ident ification or rating plate or permit condition.

(e) Compliance Schedule (1) An owner or operator of units subject to paragr aph (c)(1) shall comply with the schedule specified in Table 1146-1. (2) An owner or operator of units subject to paragr aph (c)(2) shall comply with the schedule specified in Table 1146-2. (3) On or after January 1, 2015 or during burner re placement, whichever occurs later, no person shall operate in the Distri ct any unit subject to paragraph (c)(5) which does not meet the emissions limits specified in subparagraph (c)(1)(A) of Table 1146-1. (4) Any unit subject to the requirements specified in paragraph (c)(5) that exceeds 90,000 therms of heat input from all fuels used in any twelve month period, the operators shall: (A) within 4 months after exceeding 90,000 therms o f heat input in any twelve month period, submit required applications f or permits to construct and operate; and (B) within 18 months after exceeding 90,000 therms of heat input in any twelve month period, demonstrate and maintain c ompliance with all applicable requirements of paragraphs (c)( 1), (c)(2), (c)(3), and (c)(6) for the life of the unit.Rule 1146 (Cont.) (Amended September 5, 2008)

1146-12 (5) The Executive Officer shall grant a time extens ion to the full compliance date with the applicable NOx compliance limits spec ified in subparagraphs (c)(1)(E) through (c)(1)(J) and paragraph (c)(2) fo r any health facility as
defined in Section 1250 of the California Health an d Safety Code that can
demonstrate that the Office of Statewide Health Pla nning and Development has approved an extension of time to co mply with seismic safety requirements pursuant to Health and Safety C ode Sections 130060 and 130061.5. The extension of time granted by the Executive Officer shall be consistent with the time extension granted pursuant to Health and Safety Code Section 130060 but not to exceed Januar y 1, 2015 and shall be consistent with the time extension granted pursu ant to Health and Safety Code Section 130061.5 but not to exceed Janu ary 1, 2020. Those health facilities granted a time extension shall su bmit a compliance plan to the Executive Officer on or before January 1, 2010.Rule 1146 (Cont.) (Amended September 5, 2008)

1146-13 ATTACHMENT 1

A. Equipment Tuning Procedure 1 for Forced-Draft Boilers, Steam Generators, and Process Heaters

Nothing in this Equipment Tuning Procedure shall be construed to require any act or
omission that would result in unsafe conditions or would be in violation of any regulation or requirement established by Factory Mutual, Indus trial Risk Insurers, National Fire Prevention Association, the California Department o f Industrial Relations (Occupational Safety and Health Division), the Federal Occupation al Safety and Health Administration, or other relevant regulations and requirements. Should a different tuning procedure be used, a copy of this procedure should be kept with the unit records for two years and made available t o the District personnel on request.

1. Operate the unit at the firing rate most typical of normal operation. If the unit experiences significant load variations during norm al operation, operate it at its average firing rate. 2. At this firing rate, record stack gas temperatur e, oxygen concentration, and CO concentration (for gaseous fuels) or smoke-spot num ber 2 (for liquid fuels), and observe flame conditions after unit operation stabi lizes at the firing rate selected. If the excess oxygen in the stack gas is at the low er end of the range of typical
minimum values 3 , and if CO emissions are low and there is not smok e, the unit is probably operating at near optimum efficiency - at this particular firing rate.

However, complete the remaining portion of this pro cedure to determine whether still lower oxygen levels are practical.

3. Increase combustion air flow to the furnace unti l stack gas oxygen levels increase by one to two percent over the level measured in St ep 2. As in Step 2, record the

1 This tuning procedure is based on a tune-up proce dure developed by KVB, Inc. for the United States EPA.

2 The smoke-spot number can be determined with ASTM Test Method D-2156 or with the Bacharach method. ASTM Test Method D-2156 is inclu ded in a tuneup kit that can be purchased from the Bacharach Company.

3 Typical minimum oxygen levels for boilers at high firing rates are: 1. For natural gas: 0.5% - 3% 2. For liquid fuels: 2% - 4%Rule 1146 (Cont.) (Amended September 5, 2008)

1146-14 stack gas temperature, CO concentration (for gaseou s fuels) or smoke-spot number (for liquid fuels), and observe flame condit ions for these higher oxygen levels after boiler operation stabilizes. 4. Decrease combustion air flow until the stack gas oxygen concentration is at the level measured in Step 2. From this level graduall y reduce the combustion air flow, in small increments. After each increment, r ecord the stack gas temperature, oxygen concentration, CO concentration (for gaseous fuels) and smoke-spot number (for liquid fuels). Also observe the flame and record any changes in its
condition. 5. Continue to reduce combustion air flow stepwise, until one of these limits is
reached: a. Unacceptable flame conditions - such as flame im pingement on furnace walls or burner parts, excessive flame carryover, o r flame instability. b. Stack gas CO concentrations greater than 400 ppm

. c. Smoking at the stack. d. Equipment-related limitations - such as low wind box/furnace pressure differential, built in air-flow limits, etc. 6. Develop an O 2 /CO curve (for gaseous fuels) or O 2 /smoke curve (for liquid fuels) similar to those shown in Figures 1 and 2 using the excess oxygen and CO or smoke-spot number data obtained at each combustion air flow setting.Rule 1146 (Cont.) (Amended September 5, 2008)

1146-15 7. From the curves prepared in Step 6, find the sta ck gas oxygen levels where the CO emissions or smoke-spot number equal the following values:
Fuel Measurement Value Gaseous CO Emissions 400 ppm #1 and #2 oils smoke-spot number number 1 #4 oil smoke-spot number number 2 #5 oil smoke-spot number number 3 Other oils smoke-spot number number 4

The above conditions are referred to as the CO or s moke thresholds, or as the minimum excess oxygen level. Compare this minimum value of excess oxygen to the expected value provided by
the combustion unit manufacturer. If the minimum l evel found is substantially higher than the value provided by the combustion un it manufacturer, burner adjustments can probably be made to improve fuel an d air mixing, thereby allowing operation with less air. 8. Add 0.5 to 2.0 percent O2 to the minimum excess oxygen level found in Step 7 and reset burner controls to operate automatically at this higher stack gas oxygen level. This margin above the minimum oxygen level accounts for fuel variations, variations in atmospheric conditions, load changes, and nonrepeatability or play in
automatic controls.Rule 1146 (Cont.) (Amended September 5, 2008)

1146-16 9. If the load of the combustion unit varies signif icantly during normal operation, repeat Steps 1-8 for firing rates that represent th e upper and lower limits of the range of the load. Because control adjustments at one firing rate may affect conditions at other firing rates, it may not be pos sible to establish the optimum excess oxygen level at all firing rates. If this i s the case, choose the burner control settings that give best performance over the range of firing rates. If one firing rate predominates, settings should optimize conditions a t that rate. 10. Verify that the new settings can accommodate th e sudden load changes that may occur in daily operation without adverse effects. Do this by increasing and decreasing load rapidly while observing the flame a nd stack. If any of the conditions in Step 5 result, reset the combustion c ontrols to provide a slightly higher level of excess oxygen at the affected firin g rates. Next, verify these new settings in a similar fashion. Then make sure that the final control settings are recorded at steady-state operating conditions for f uture reference. 11. When the above checks and adjustments have been made, record data and attach combustion analysis data to boiler, steam generator , or heater records indicating name and signature of person, title, and date the t uneup was performed.

B. Equipment Tuning Procedure for Natural Draft-Fir ed Boilers, Steam Generators, and Process Heaters.

Nothing in this Equipment Tuning Procedure shall be construed to require any act or
omission that would result in unsafe conditions or would be in violation of any regulation or requirement established by Factory Mutual, Indus trial Risk Insurers, National Fire Prevention Association, the California Department o f Industrial Relations (Occupational Safety and Health Division), the Federal Occupation al Safety and Health Administration, or other relevant codes, regulations, and equipment manufacturers specifications and operating manuals.

Should a different tuning procedure be used, a copy of this procedure should be kept with the unit records for two years and made available t o the District personnel on request.

1. PRELIMINARY ANALYSIS
a. CHECK THE OPERATING PRESSURE OR TEMPERATURE. Operate the boiler, steam generator, or heater at t he lowest acceptable pressure or temperature that will satisfy the load demand. This will
minimize heat and radiation losses. Determine the pressure or temperatureRule 1146 (Cont.) (Amended September 5, 2008)

1146-17 that will be used as a basis for comparative combus tion analysis before and after tuneup.
b. CHECK OPERATING HOURS. Plan the workload so that the boiler, steam generat or, or process heater operates only the minimum hours and days necessary to perform the work required. Fewer operating hours will reduce fuel u se and emissions. For units requiring a tuneup to comply with the rule, a totalizing non-resettable fuel meter will be required for each fuel used and for each boiler, steam generator, and heater to prove fuel consumption is less than the heat input limit in therms per year specified in the rule.
c. CHECK AIR SUPPLY. Sufficient fresh air supply is essential to ensure optimum combustion and the area of air supply openings must be in complian ce with applicable codes and regulations. Air openings must be kept w ide open when the burner is firing and clear from restriction to flow

. d. CHECK VENT. Proper venting is essential to assure efficient com bustion. Insufficient draft or overdraft promotes hazards and inefficient burning. Check to be sure that vent is in good condition, sized properly and with no
obstructions.
e. COMBUSTION ANALYSIS. Perform an "as is" combustion analysis (CO, O2, etc .) with a warmed up unit at high and low fire, if possible. In additio n to data obtained from combustion analysis, also record the following: i. Inlet fuel pressure at burner (at high & low fir e) ii. Draft at inlet to draft hood or barometric damp er 1) Draft hood: high, medium, and low 2) Barometric Damper: high, medium, and low iii. Steam pressure, water temperature, or process fluid pressure or temperature entering and leaving the boiler, steam generator, or process heater.
iv. Unit rate if meter is available.

With above conditions recorded, make the following checks and corrective actions as necessary:Rule 1146 (Cont.) (Amended September 5, 2008)

1146-18 2. CHECKS & CORRECTIONS
a. CHECK BURNER CONDITION. Dirty burners or burner orifices will cause boiler, steam generator, or process heater output rate and thermal efficiency t o decrease. Clean burners and burner orifices thoroughly. Also, ensu re that fuel filters and moisture traps are in place, clean, and operating p roperly, to prevent plugging of gas orifices. Confirm proper location and orientation of burner diffuser spuds, gas canes, etc. Look for an y burned-off or missing burner parts, and replace as needed. b. CHECK FOR CLEAN BOILER, STEAM GENERATOR, OR PROC ESS
HEATER TUBES & HEAT TRANSFER SURFACES. External and internal build-up of sediment and scal e on the heating surfaces creates an insulating effect that quickly reduces unit efficiency.
Excessive fuel cost will result if the unit is not kept clean. Clean tube surfaces, remove scale and soot, assure proper proc ess fluid flow and flue gas flow.
c. CHECK WATER TREATMENT & BLOWDOWN PROGRAM. Soft water and the proper water or process fluid tr eatment must be uniformly used to minimize scale and corrosion. Ti mely flushing and periodic blowdown must be employed to eliminate sed iment and scale build-up on a boiler, steam generator or process he ater. d. CHECK FOR STEAM, HOT WATER OR PROCESS FLUID LEAK S. Repair all leaks immediately since even small high- pressure leaks quickly lead to considerable fuel, water and steam losses. Be sure there are no leaks through the blow-off, drains, safety valve, b y-pass lines or at the feed pump, if used.

3. SAFETY CHECKS a. Test primary and secondary low water level contr ols. b. Check operating and limit pressure and temperatu re controls. c. Check pilot safety shut off operation. d. Check safety valve pressure and capacity to meet boiler, steam generator or process heater requirements. e. Check limit safety control and spill switch.Rule 1146 (Cont.) (Amended September 5, 2008)

1146-19 4. ADJUSTMENTS While taking combustion readings with a warmed up b oiler, steam generator, or process heater at high fire perform checks and adju stments as follows: a. Adjust unit to fire at rate; record fuel manifol d pressure. b. Adjust draft and/or fuel pressure to obtain acce ptable, clean combustion at both high, medium and low fire. Carbon Monoxide (C O) value should always be below 400 parts per million (PPM) at 3% 0 2. If CO is high make necessary adjustments.

Check to ensure boiler, steam generator, or process heater light offs are smooth and safe. A reduced fuel pressure test at b oth high and low fire
should be conducted in accordance with the manufact urers instructions
and maintenance manuals. c. Check and adjust operation of modulation control ler. Ensure proper, efficient and clean combustion through range of fir ing rates. When above adjustments and corrections have been ma de, record all data.

5. FINAL TEST Perform a final combustion analysis with a warmed u p boiler, steam generator, or process heater at high, medium and low fire, whenev er possible. In addition to data from combustion analysis, also check and recor d: a. Fuel pressure at burner (High, Medium, and Low). b. Draft above draft hood or barometric damper (Hig h, Medium and Low). c. Steam pressure or water temperature entering and leaving boiler, steam generator, or process heater.
d. Unit rate if meter is available. When the above checks and adjustments have been mad e, record data and attach combustion analysis data to boiler, steam generator , or process heater records indicating name and signature of person, title, com pany name, company address and date the tuneup was performed.