Minnesota Administrative Rules
Agency 151 - Labor and Industry Department
Chapter 1346 - MINNESOTA MECHANICAL AND FUEL GAS CODES
Chapter 8 - INSTALLATION AND TESTING OF FUEL GAS-FIRED EQUIPMENT
Part 1346.5900 - CHAPTER 9, INSTALLATION AND TESTING OF FUEL GAS-FIRED EQUIPMENT

Universal Citation: MN Rules 1346.5900

Current through Register Vol. 49, No. 13, September 23, 2024

Subpart 1. Chapter 9.

The IFGC is amended by adding a chapter to read as follows:

CHAPTER 9

Subp. 2. Installation and testing of fuel gas-fired equipment; general.

Chapter 9 shall regulate the installation and testing or repair of gas or fuel burning systems, gas or fuel burners, and gas or fuel burning equipment installed within, or in conjunction with, building or structures. The requirements of this chapter shall apply to the following equipment:

1. Equipment utilized to provide control of environmental conditions.

Exception: Equipment and appliances listed and labeled to an appropriate standard by a nationally recognized testing laboratory, which is qualified to evaluate the equipment or appliance, when installed and tested according to the manufacturer's installation instructions.

2. Equipment with a fuel input of 1,000,000 Btu/hr or greater.

3. Unlisted equipment.

4. Miscellaneous equipment when required by the building official.

Subp. 3. Placing equipment in operation.

After completion of the installation, all safety and operating controls and venting shall be tested before placing the burner in service. The correct input of fuel shall be determined and the fuel-to-air ratio set. Each gas or fuel burner shall be adjusted to its proper input according to the manufacturer's instructions. Overrating the burners or appliance is prohibited. Btu/hr input range shall be appropriate to the appliance.

1. The rate of flow of the gas or fuel shall be adjusted to within plus or minus two percent of the required Btu/hr rating at the manifold pressure specified by the manufacturer. When the prevailing pressure is less than the manifold pressure specified, the rates shall be adjusted at the prevailing pressure.

2. For conversion burners installed in hot water (liquid) boilers or warm air furnaces, the rate of flow of the gas or fuel in Btu/hr shall be adjusted to within plus or minus five percent of the calculated Btu/hr heat loss of the building in which it is installed, or the design load, and shall not exceed the design rate of the appliance.

3. For conversion burners installed in steam boilers, the gas or fuel hourly input demand shall be adjusted to meet the steam load requirements. The gas or fuel input demand necessitated by an oversized boiler shall be established and added to the input demand for load requirements to arrive at a total input demand.

Subp. 4. Pilot operation.

Pilot flames shall ignite the gas or fuel at the main burner or burners and shall be adequately protected from drafts.

Pilot flames shall not become extinguished during pilot cycle when the main burner or burners are turned on or off in a normal manner, either manually or by automatic controls.

Subp. 5. Burner operation.

When testing to determine compliance with this section, care shall be exercised to prevent the accumulation of unburned gas or fuel in the appliance or flues that might result in explosion or fire.

1. The flames from each burner shall freely ignite the gas or fuel from adjacent burners when operating at the prevailing gas or fuel pressure and when the main control valve is regulated to deliver at one-third of the fuel gas or fuel rate.

2. Burner flames shall not flash back after immediate ignition nor after turning the fuel cock until the flow rate to the burner is one-third the full supply.

3. Burner flames shall not flash back when the gas or fuel is turned on or off by an automatic control mechanism.

4. Main burner flames shall ignite freely from each pilot when the main control valve is regulated to one-third the full gas or fuel rate and when the pilot flame is reduced to a minimum point at which it will actuate the safety device.

5. When ignition is made in a normal manner, the flame shall not flash outside the appliance.

6. Burners shall not expel gas or fuel through air openings when operating at prevailing pressure.

7. Burners shall have proper fuel air mixture to ensure smooth ignition of the main burner.

8. Dual fuel burners may have controls common or independent to both fuels. Transfer from one fuel to the other shall be by a manual interlock switching system to prevent the gas and other fuel being used simultaneously except by special permission from the building official. The building official shall consider whether an exception will provide equivalent safety. The transfer switch shall have a center off position and shall not pass through the center off position without stopping in the center off position.

Subp. 6. Method of test.

1. Operational checking. The flue gas, venting, safety and operating controls of the appliance shall be checked to ensure proper and safe operation.

2. Method of test - atmospheric type/induced draft type/fan-assisted type. The appliance shall be allowed to operate until the stack temperature becomes stabilized after which a sample of the undiluted flue products shall be taken from the appliance flue outlet. The sample taken shall be analyzed for carbon monoxide, carbon dioxide and oxygen. Stack temperature shall be noted.

Note: Appliance designs incorporating induced draft assemblies may require a flue gas sample to be taken after the draft regulator or induced draft fan.

3.1. Performance standards for atmospheric type.
a. Minimum of 75 percent efficiency as determined by flue gas analysis method at appliance flue outlet.

b. Carbon monoxide concentration in flue gas not greater than 0.04 percent on an air-free basis.

c. Stack temperature not greater than 480°F, plus ambient.

d. Carbon dioxide concentration between 6 and 9 percent, inclusive.

e. Oxygen concentration between 4 and 10 percent, inclusive.

3.2. Performance standards for induced draft type/fan-assisted type.
a. Minimum of 75 percent efficiency as determined by flue gas analysis method at appliance flue outlet.

b. Carbon monoxide concentration in flue gas not greater than 0.04 percent on an air free basis.

c. Stack temperature not greater than 480°F, plus ambient.

d. Oxygen concentration between 4 and 10 percent, inclusive, with carbon dioxide concentration between 6 and 9 percent, inclusive. Note: Induced draft type and fan-assisted type appliances may require a sample to be taken after the induced draft fan, which may cause oxygen figures in excess of limits stated. In such cases, safe fuel combustion ratios shall be maintained and be consistent with appliance listing.

4. Method of test - power type. The appliance shall be allowed to operate until the stack temperature becomes stabilized after which a sample of the undiluted flue products shall be taken from the appliance flue outlet. The sample shall be analyzed for carbon monoxide, carbon dioxide and oxygen. Stack temperature shall be recorded.

5. Performance standards for power type.
a. Minimum of 80 percent efficiency as determined by flue gas analysis method method at appliance flue outlet.

b. Carbon monoxide concentration in flue gas not greater than 0.04 percent.

c. Stack temperature not greater than 480°F plus ambient, or 125°F in excess of fluid temperature plus ambient.

d. Carbon dioxide concentration between 6 and 9 percent, inclusive.

e. Oxygen concentration between 3 and 10 percent, inclusive.

6. After completion of the test of newly installed gas or fuel burner equipment as provided in this section, complete test records shall be filed with the building official on an approved form. The tag stating the date of the test and the name of the installer shall be attached to the appliance at the main valve.

7. Oxygen concentration.
a. The concentration of oxygen in the undiluted flue products of gas or fuel burners shall in no case be less than 3 percent nor more than 10 percent, shall be in conformance with applicable performance standards and shall be consistent with the appliance listing.

b. The allowable limit of carbon monoxide shall not exceed 0.04 percent.

c. The flue gas temperature of a gas appliance, as taken on the appliance side of the draft regulator, shall not exceed applicable performance standards and shall be consistent with the appliance listing.

8. Approved oxygen trim system. The oxygen figures may not apply when there is an approved oxygen trim system on the burner that is designed for that use, including a low oxygen interlock when approved by the building official. The building official shall consider whether an exception will provide equivalent safety.

9. Supervised start-up.
a. Supervised start-up may be required to verify safe operation of gas or fuel burner and to provide documentation that operation is consistent with this code, listing and approval. Supervised start-up is required for all fuel burners in b, c, and d. Supervised startup requires that fuel burners shall be tested in the presence of the building official in an approved manner. Testing shall include safety and operating controls, input, flue gas analysis, and venting. Flue gas shall be tested at high, medium and low fires. Provisions shall be made in the system to allow firing test in warm weather. After completion of the test of newly installed gas or fuel burner equipment as provided in this section, complete test records shall be filed with the building official on an approved form. The tag stating the date of the test and the name of the installer shall be attached to the appliance at the main valve.

b. Gas and fuel burners of 1,000,000 Btu/hr input or more require a supervised start-up as in a.

c. Installation of oxygen trim systems, modulating dampers, or other draft control or combustion devices require a supervised startup as in a.

d. All direct fired heaters require a supervised start-up as in a.

10. A complete control diagram of the installation and suitable operating instructions shall be supplied to the building official.

Subp. 7. Pressure regulators.

(a) General.
1. Regulators shall be provided with access for servicing.

2. Regulators shall be provided with a shutoff valve, union and test taps (both upstream and downstream of the regulator) for servicing.

3. All regulators with inlet gas pressure exceeding 14 inches water column pressure or used on an appliance having an input exceeding 400,000 Btu/hr shall have an approved high pressure manual gas valve in the supply piping upstream of the regulator.

4. All regulators with inlet gas pressure exceeding 14 inches water column pressure or used on an appliance having an input exceeding 400.000 Btu/hr shall be vented to the outdoors in separate vents sized according to the manufacturer's specifications.

Exception: Regulators equipped with limiting orifices installed in accordance with amended IFGC Section 410.3.

5. Regulators may not be vented into a combustion chamber or an appliance vent.

6. Regulator vents shall terminate at least 3 feet (914 mm) from doors, operable windows, nonmechanical intake openings, and openings into direct-vent appliances. The vent termination shall be located at least 12 inches (305 mm) above grade and shall be suitably screened and hooded to prevent accidental closure of the vent pipe.

7. All pounds-to-pounds and pounds-to-inches regulators used as appliance regulators where downstream controls are not rated for upstream pressure shall be of the full lock-up type.

(b) Appliance.
1. Appliance regulators shall be installed consistent with the listing and approval of the equipment and the listing and approval of the regulator manufacturer.

2. Each gas burner or appliance shall have its own gas pressure regulator. This appliance regulator is in addition to any pounds-to-pounds or pounds-to-inches regulators in the system.

Subp. 8. Equipment information.

A. All installations of gas or fuel burners with input above 400,000 Btu/hr and all combination gas or fuel burners shall be approved before installation. The following information shall be supplied if required by the building official.
1. Name, model, and serial number of the burner.

2. Input rating and type of fuel.

3. Name of the nationally recognized testing laboratory that tested and listed the unit.

4. Name, model, and serial number of the furnace or boiler that the burner will be installed in if not part of a complete package.

5. A complete wiring diagram showing the factory and fuel wiring installed or to be installed including all controls, identified by the brand name and model number.

6. A print of the gas or fuel train from the manual shutoff to the appliance showing all controls that will be installed, their names, model numbers, and approvals.

B. All installations of gas or fuel burners with input above 400,000 Btu/hr and all combination gas and oil or other combination fuel burners that are installed in new or renovated boiler or equipment rooms, or are installed in a package with the boiler or furnace, shall include the following information in addition to that required in item A, subitems 1 to 6.
1. A complete piping diagram from the supply source showing all components and materials identified by brand name and model number with relevant approvals.

2. Detailed provisions for combustion air, venting, and stacks.

3. A floor plan drawn to scale showing all relevant equipment. Plans and specifications shall be approved before proceeding with an installation.

Disclaimer: These regulations may not be the most recent version. Minnesota may have more current or accurate information. We make no warranties or guarantees about the accuracy, completeness, or adequacy of the information contained on this site or the information linked to on the state site. Please check official sources.
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