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Boilers, Water Heaters and Pressure Vessels (18-28-1001 et seq.)

Municipal Code of Chicago tit. 18, ch. 18-28, art. X
in effect

Municipal Code of Chicago § 18-28-1001.1 Scope.

18-28-1001.1 Scope. This article shall govern the installation, alteration and repair of boilers, water heaters and pressure vessels. Exceptions: 1. Pressure vessels used for unheated water supply. 2. Portable unfired pressure vessels and United States Department of Transportation containers. 3. Containers for bulk oxygen and medical gas. 4. Unfired pressure vessels having a volume of 5 cubic feet (0.14 m 3 ) or less operating at pressures not exceeding 250 pounds per square inch (1724 kPa) and located within occupancies of Group B, F, H, M, R, S or U. 5. Pressure vessels used in refrigeration systems that are regulated by Article 11 of this chapter. 6. Pressure tanks used in conjunction with coaxial cables, telephone cables, power cables and other similar humidity control systems. 7. Any boiler or pressure vessel subject to inspection by federal or state inspectors. (Amend Coun. J. 9-14-21, p. 35949, Art. X, § 1; Amend Coun. J. 11-7-22, p. 54984, § 15)

Municipal Code of Chicago § 18-28-1002.1 General.

18-28-1002.1 General. Potable water heaters and hot water storage tanks shall be listed, labeled and installed in accordance with the manufacturer's installation instructions, the Chicago Plumbing Code and this chapter. Potable hot water storage tanks heated by indirect means shall be designed, constructed, and installed in accordance with Section VIII of the ASME Boiler and Pressure Vessel Code unless all of the following requirements are met: 1. The storage tank has a heat input of less than 200,000 BTU/hr. 2. The storage tank has a capacity of less than 120 gallons. 3. The storage tank maximum operating temperature is less than 210°F (99°C). Potable hot water storage tanks heated by indirect means that meet all three of the above requirements shall be governed by the Chicago Plumbing Code. All water heaters shall be capable of being removed without first having to remove a permanent portion of the building structure. The potable water connections and relief valves for all water heaters shall conform to the requirements of the Chicago Plumbing Code. Water heaters with open flames that use combustion air from a machinery room shall not be installed in a machinery room except as allowed in Section 18-28-1105. (Amend Coun. J. 9-14-21, p. 35949, Art. X, § 2)

Municipal Code of Chicago § 18-28-1003.1 General.

18-28-1003.1 General. All pressure vessels, unless otherwise approved, shall be constructed and certified in accordance with the ASME Boiler and Pressure Vessel Code and shall be installed in accordance with the manufacturer's installation instructions and nationally recognized standards. Directly fired pressure vessels shall meet the requirements of Section 1004. (Amend Coun. J. 9-14-21, p. 35949, Art. X, § 3)

Municipal Code of Chicago § 18-28-1003.2 Piping.

18-28-1003.2 Piping. All piping materials, fittings, joints, connections and devices associated with systems used in conjunction with pressure vessels shall be designed for the specific application. (Amend Coun. J. 9-14-21, p. 35949, Art. X, § 3)

Municipal Code of Chicago § 18-28-1003.3 Welding.

18-28-1003.3 Welding. Welding on pressure vessels shall be performed by an R-Stamp holder in accordance with the National Board Inspection Code, Part 3, or in accordance with an approved standard. (Amend Coun. J. 9-14-21, p. 35949, Art. X, § 3)

Municipal Code of Chicago § 18-28-1004.1 Standards.

18-28-1004.1 Standards. Boilers shall be designed, constructed and certified in accordance with the ASME Boiler and Pressure Vessel Code, Section I or IV. Controls and safety devices for boilers with fuel input ratings of less than 12,500,000 Btu/hr (3,662,500 W) shall meet the requirements of ASME CSD-1. Controls and safety devices for boilers with inputs greater than or equal to 12,500,000 Btu/hr (3,662,500 W) shall meet the requirements of NFPA 85. Packaged oil-fired boilers and their control systems shall be listed and labeled in accordance with UL 726. Packaged electric boilers and their control systems shall be listed and labeled in accordance with UL 834. Solid-fuel-fired boilers shall be listed and labeled in accordance with UL 2523. Boiler external piping falls within the jurisdiction of the ASME Code and shall be ASME Code certified. (Amend Coun. J. 9-14-21, p. 35949, Art. X, § 4)

Municipal Code of Chicago § 18-28-1004.1.1 Non-boiler external piping.

18-28-1004.1.1 Non-boiler external piping. Non-boiler external piping connected to regulated boilers shall be designed, constructed and installed in accordance with the requirements of ASME and ANSI B31.1 and B31.9.

Municipal Code of Chicago § 18-28-1004.2 Installation.

18-28-1004.2 Installation. In addition to the requirements of this chapter, the installation of boilers shall conform to the manufacturer's instructions. Operating instructions of a permanent type shall be attached to the boiler. Boilers shall have all controls set, adjusted and tested by the installer. The manufacturer's rating data and the nameplate shall be attached to the boiler. (Amend Coun. J. 9-14-21, p. 35949, Art. X, § 4)

Municipal Code of Chicago § 18-28-1004.3 Working clearance.

18-28-1004.3 Working clearance. Clearances shall be maintained around boilers, generators, heaters, tanks and related equipment and appliances so as to permit inspection, servicing, repair, replacement and visibility of all gauges. If boilers are installed or replaced, clearance shall be provided to allow access for inspection, maintenance and repair. Passageways around all sides of boilers shall have an unobstructed width of not less than 18 inches (457 mm), unless otherwise approved.

Municipal Code of Chicago § 18-28-1004.3.1 Top clearance.

18-28-1004.3.1 Top clearance. The following boilers shall have a minimum clearance of 7 feet (2134 mm) from the top of the boiler to the ceiling: High-pressure steam boilers that have a steam-generating capacity in excess of 5,000 pounds per hour (2268 kg/h), or a heating surface in excess of 1,000 square feet(93 m 2 ), or an input in excess of 5,000,000 BTU/hr (1465 kW). The following boilers shall have a minimum clearance of 3 feet (914 mm) from the top of the boiler to the ceiling: (1) Steam-heating boilers and hot-water-heating boilers that exceed one of the following limits: 5,000,000 BTU/hr input (1465 kW); or 5,000 pounds of steam per hour (2268 kg/h) capacity or a heating surface in excess of 1,000 square-foot (93 m 2 ); and (2) high-pressure steam boilers that do not exceed one of the following limits: 5,000,000 BTU/hr input (1465 kW); or 5,000 pounds of steam per hour (2268 kg/h) Capacity or heating surface in excess of a 1,000-square-foot (93 m 2 ); and (3) all boilers with manholes on top of the boiler. The following boilers shall have a minimum clearance of 2 feet (610 mm) from the ceiling: package boilers, steam-heating boilers and hot-water-heating boilers which do not have manholes on top of the shell and which do not exceed any one of the limits of this section.

Municipal Code of Chicago § 18-28-1004.4 Mounting.

18-28-1004.4 Mounting. Equipment and appliances shall be set or mounted on a level base capable of supporting and distributing the weight contained thereon. Boilers, tanks, equipment and appliances shall be securely anchored to the structure. Equipment and appliances requiring vibration isolation shall be installed as designed by a registered design professional.

Municipal Code of Chicago § 18-28-1004.5 Floors.

18-28-1004.5 Floors. Boilers shall be mounted on noncombustible floors with noncombustible flooring and surface finish and with no combustible material against the underside thereof; or, on fire resistance slabs or arches having no combustible materials against the underside there of unless the boiler is specifically listed for installation on a combustible floor or the floor is protected in an approved manner and the installation is approved by a registered professional engineer.

Municipal Code of Chicago § 18-28-1004.6 Boiler rooms and enclosures.

18-28-1004.6 Boiler rooms and enclosures. Boiler rooms and enclosures and access thereto shall comply with the Chicago Building Code and Article 3. Boiler rooms shall be equipped with a floor drain or other approved means for disposing of liquid waste. Boilers with open flames that use combustion air from a room shall not be installed in any machinery room except as allowed in Article 11. (Amend Coun. J. 9-14-21, p. 35949, Art. X, § 4)

Municipal Code of Chicago § 18-28-1004.7 Operating adjustments and instructions.

18-28-1004.7 Operating adjustments and instructions. Hot water and steam boilers shall have all operating and safety controls set and operationally tested by the installing contractor. A complete control diagram and the boiler operating instructions shall be furnished to the building owner by the installer for each installation.

Municipal Code of Chicago § 18-28-1004.8 Stationary engineers.

18-28-1004.8 Stationary engineers. The following regulated devices subject to the provisions of this chapter shall only be used, managed or operated by a stationary engineer who is licensed in accordance with Chapter 4-344: 1. Steam engines and steam boilers with an output capacity in excess of 50 boiler horsepower or intended for operation at a pressure in excess of 10 psig. 2. Hot water boilers intended for operation at a pressure in excess of 160 psi or temperatures in excess of 250°F (121°C). (Amend Coun. J. 9-14-21, p. 35949, Art. X, § 4)

Municipal Code of Chicago § 18-28-1005.1 Valves.

18-28-1005.1 Valves. Every boiler or modular boiler shall have a shutoff valve in the supply and return piping. For multiple boiler or multiple modular boiler installations, each boiler or modular boiler shall have individual shut off valves in the supply and return piping in accordance with the ASME Code. Exception: Shutoff valves are not required in a system having a single low-pressure steam boiler.

Municipal Code of Chicago § 18-28-1005.2 Potable water supply.

18-28-1005.2 Potable water supply. The water supply to all boilers shall be connected in accordance with the Chicago Plumbing Code. (Amend Coun. J. 11-8-12, p. 38872, § 323; Amend Coun. J. 9-14-21, p. 35949, Art. X, § 5)

Municipal Code of Chicago § 18-28-1006.1 Safety valve for steam boilers.

18-28-1006.1 Safety valve for steam boilers. All steam boilers shall be protected with a safety valve or valves as required by the ASME Code.

Municipal Code of Chicago § 18-28-1006.2 Safety relief valves for hot water boilers.

18-28-1006.2 Safety relief valves for hot water boilers. Hot water boilers shall be protected with a safety relief valve or valves as required by the ASME Code.

Municipal Code of Chicago § 18-28-1006.3 Pressure relief for pressure vessels.

18-28-1006.3 Pressure relief for pressure vessels. All pressure vessels shall be protected with a pressure relief valve or pressure-limiting device, such as a rupture disc, as required by the manufacturer's installation instructions for the pressure vessel in accordance with Section VIII of the ASME Code.

Municipal Code of Chicago § 18-28-1006.4 Approval of safety and safety relief valves.

18-28-1006.4 Approval of safety and safety relief valves. Safety and safety relief valves shall be listed and labeled by the ASME Code. Safety and safety relief valves shall have a minimum rated capacity for the equipment or appliances served. Safety and safety relief valves shall be set in accordance with the ASME Code.

Municipal Code of Chicago § 18-28-1006.5 Installation.

18-28-1006.5 Installation. Safety or relief valves or other approved pressure relieving devices shall be connected to the safety or relief valve opening on the boiler or pressure vessel. No valves shall be located on either side of a safety or relief valve connection. The relief valve discharge shall allow water to be drained with no buildup. The relief valve shall discharge by gravity.

Municipal Code of Chicago § 18-28-1006.6 Safety and relief valve discharge.

18-28-1006.6 Safety and relief valve discharge. Safety and relief valve discharge pipes shall be constructed of rigid pipe that is approved for the temperature of the system. The discharge pipe shall be the same diameter as the safety or relief valve outlet. Safety and relief valves shall not discharge in a manner that creates a hazard or a potential cause of damage or otherwise constitutes a nuisance. High-pressure-steam safety valves shall be vented to the outside of the structure. If a low-pressure safety valve or a relief valve discharges to the drainage system, the installation shall conform to the ASME Code and the Chicago Plumbing Code. (Amend Coun. J. 9-14-21, p. 35949, Art. X, § 6)

Municipal Code of Chicago § 18-28-1006.7 Boiler safety devices.

18-28-1006.7 Boiler safety devices. Boilers shall be equipped with controls and limit devices as required by the ASME Code, the manufacturer's installation instructions and the conditions of the listing.

Municipal Code of Chicago § 18-28-1006.8 Electrical requirements.

18-28-1006.8 Electrical requirements. The power supply to the electrical control system shall be from a two-wire branch circuit that has a grounded conductor, or from an isolation transformer with a two-wire secondary. If an isolation transformer is provided, one conductor of the secondary winding shall be grounded. Control voltage shall not exceed 150 volts nominal line to line. Control and limit devices shall interrupt the ungrounded side of the circuit. A means of manually disconnecting the control circuit shall be provided and controls shall be arranged so that when de-energized, the burner shall be inoperative. Such disconnecting means shall be capable of being locked in the off position and shall be provided with ready access. Electrical conduit and wire shall not be installed in the floor slab under a boiler.

Municipal Code of Chicago § 18-28-1007.1 General.

18-28-1007.1 General. All steam and hot water boilers shall be protected with a low-water cutoff control or controls as required by Section VIII of the ASME Code. (Amend Coun. J. 11-8-12, p. 38872, § 324)

Municipal Code of Chicago § 18-28-1007.2 Operation.

18-28-1007.2 Operation. The low-water cutoff shall automatically stop the combustion operation of the appliance when the water level drops below the lowest safe water level as defined in the ASME Code.

Municipal Code of Chicago § 18-28-1008.1 General.

18-28-1008.1 General. Every steam boiler shall be equipped with a quick-opening blowoff valve. Steam boilers with an allowable working pressure in excess of 100 psi shall include a second valve; the valve closest to the boiler shall be quick-acting; the second valve shall be slow-acting. The valve(s) shall be installed in the opening provided on the boiler. The minimum size of the valve or valves shall be specified in accordance with Sections I and IV the ASME Code.

Municipal Code of Chicago § 18-28-1008.2 Discharge.

18-28-1008.2 Discharge. Blowoff valves shall discharge to a safe place of disposal. Blowoff valves for high pressure steam boilers shall discharge into a tank in accordance with the ASME Code Section VIII.

Municipal Code of Chicago § 18-28-1009.1 Where required.

18-28-1009.1 Where required. An expansion tank shall be installed in every hot water system. For multiple boiler installations, a minimum of one expansion tank is required. Expansion tanks shall be of the closed or open type. Tanks shall be rated for the pressure of the hot water system. Expansion tanks for systems designed to operate above 30 psi shall be constructed in accordance with the ASME Code, Section VIII, Division I.

Municipal Code of Chicago § 18-28-1009.2 Closed-type expansion tanks.

18-28-1009.2 Closed-type expansion tanks. Closed-type expansion tanks shall be installed in accordance with the manufacturer's installation instructions. The size of the tank shall be based on the capacity of the hot-water-heating system.

Municipal Code of Chicago § 18-28-1009.3 Open-type expansion tanks.

18-28-1009.3 Open-type expansion tanks. Open-type expansion tanks shall be located a minimum of 4 feet (1219 mm) above the highest heating element. The tank shall be adequately sized for the hot water system. An overflow with a minimum diameter of 1 inch (25.4 mm) shall be installed at the top of the tank. The overflow shall discharge to the drainage system in accordance with the Chicago Plumbing Code. (Amend Coun. J. 9-14-21, p. 35949, Art. X, § 7)

Municipal Code of Chicago § 18-28-1010.1 Hot water boiler gauges.

18-28-1010.1 Hot water boiler gauges. Every hot water boiler shall have a pressure gauge and a temperature gauge, or a combination pressure and temperature gauge. The gauges shall indicate the temperature and pressure within the normal range of the system's operation.

Municipal Code of Chicago § 18-28-1010.2 Steam boiler gauges.

18-28-1010.2 Steam boiler gauges. Every steam boiler shall have a water-gauge glass and a pressure gauge. The pressure gauge scale shall be in accordance with the ASME Code and shall indicate the pressure up to 1 1/2 times the maximum allowable working pressure of the boiler, but not less than 30 psi.

Municipal Code of Chicago § 18-28-1010.2.1 Water-gauge glass.

18-28-1010.2.1 Water-gauge glass. The gauge glass shall be installed so that the midpoint is at the normal boiler water level. The lowest point of the gauge glass shall be a minimum of one inch above the lowest permissible water level recommended by the boiler manufacturer.

Municipal Code of Chicago § 18-28-1011.1 Tests.

18-28-1011.1 Tests. Upon completion of the assembly and installation of boilers and pressure vessels, acceptance tests shall be conducted in accordance with the requirements of the ASME Boiler and Pressure Vessel Code. If field assembly of pressure vessels or boilers is required, a copy of the completed U-1 Manufacturers Data Report required by the ASME Boiler and Pressure Vessel Code shall be submitted to the Department of Buildings.

Municipal Code of Chicago § 18-28-1011.2 Test gauges.

18-28-1011.2 Test gauges. An indicating test gauge shall be connected directly to the boiler or pressure vessel and located where it is visible to the operator throughout the duration of the test. The pressure gauge scale shall be graduated over a range of not less than one and one-half times the maximum test pressure and not greater than four times the maximum test pressure. All gauges utilized for testing shall be calibrated and certified by the test operator.
Source: City of Chicago, Municipal Code of Chicago (American Legal Publishing, codelibrary.amlegal.com)URL: https://codelibrary.amlegal.com/codes/chicago/latest/chicago_il/0-0-0-2688566Fetched: 10/24/2026

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