235100-RIB-Breechings, Chimneys, and Stacks-12-24-2025.pdf

25-388 CBI HVAC and Lighting Upgrade 235100 - 1 Breechings, Chimneys, and

Stacks

SECTION 235100

BREECHINGS, CHIMNEYS, AND STACKS

PART 1 GENERAL

1.01 SECTION INCLUDES

A. Field fabricated breechings.

B. Manufactured breechings.

C. Type B double wall gas vents.

D. Double wall metal stacks.

E. Induced draft fans.

1.02 RELATED REQUIREMENTS

A. Section 230513 - Common Motor Requirements for HVAC Equipment: Induced draft fan motor.

B. Section 260583 - Wiring Connections: Electrical characteristics and wiring connections.

1.03 REFERENCE STANDARDS

A. ANSI Z21.66 - Automatic Damper Devices for Use with Gas-Fired Appliances; 2023.

B. ASTM A653/A653M - Standard Specification for Steel Sheet, Zinc-Coated (Galvanized) or Zinc-

Iron Alloy-Coated (Galvannealed) by the Hot-Dip Process; 2025.

C. ASTM A1011/A1011M - Standard Specification for Steel, Sheet and Strip, Hot-Rolled, Carbon, Structural, High-Strength Low-Alloy, High-Strength Low-Alloy with Improved Formability, and Ultra-High Strength; 2023.

D. NFPA 54 - National Fuel Gas Code; 2024.

E. NFPA 70 - National Electrical Code; Most Recent Edition Adopted by Authority Having

Jurisdiction, Including All Applicable Amendments and Supplements.

F. NFPA 82 - Standard on Incinerators and Waste and Linen Handling Systems and Equipment;

2024.

G. NFPA 211 - Standard for Chimneys, Fireplaces, Vents, and Solid Fuel-Burning Appliances;

2024.

H. SMACNA (DCS) - HVAC Duct Construction Standards Metal and Flexible; 2020.

I. UL 103 - Factory-Built Chimneys for Residential Type and Building Heating Appliances; Current

Edition, Including All Revisions.

J. UL 378 - Standard for Draft Equipment; Current Edition, Including All Revisions.

K. UL 441 - Standard for Gas Vents; Current Edition, Including All Revisions.

1.04 DEFINITIONS

A. Breeching: Vent connector.

B. Chimney: Primarily vertical shaft enclosing at least one vent for conducting flue gases outdoors.

C. Smoke Pipe: Round, single wall vent connector.

D. Vent: That portion of a venting system designed to convey flue gases directly outdoors from a vent connector or from an appliance when a vent connector is not used.

E. Vent Connector: That part of a venting system that conducts the flue gases from the flue collar of an appliance to a chimney or vent, and may include a draft control device.

1.05 ADMINISTRATIVE REQUIREMENTS

A. Preinstallation Meeting: Conduct a preinstallation meeting one week prior to the start of the work of this section; require attendance by all affected installers.

Upgrade 235100 - 2 Breechings, Chimneys, and

Stacks

B. Sequencing: Ensure that utility connections are achieved in an orderly and expeditious manner.

1.06 SUBMITTALS

A. See Section 013000 - Administrative Requirements for submittal procedures.

B. Product Data: Provide data indicating factory built chimneys, including dimensional details of components and flue caps, dimensions and weights, electrical characteristics and connection requirements.

C. Shop Drawings: Indicate general construction, dimensions, weights, support and layout of breechings. Submit layout drawings indicating plan view and elevations where factory-built units are used.

D. Manufacturer's Instructions: Include installation instructions, and indicate assembly, support details, and connection requirements.

1.07 QUALITY ASSURANCE

A. Manufacturer Qualifications: Company specializing in manufacturing the type of products specified in this section, with minimum three years of documented experience.

PART 2 PRODUCTS

2.01 BREECHINGS, CHIMNEYS, AND STACKS - GENERAL REQUIREMENTS

A. Regulatory Requirements:

1. Comply with applicable codes for installation of natural gas burning appliances and equipment.

2. Products Requiring Electrical Connection: Listed and classified by Underwriters

Laboratories Inc. as suitable for the purpose specified and indicated.

2.02 FIELD FABRICATED BREECHINGS

A. Breechings 24 inches or More in Diameter: Fabricate from ASTM A1011/A1011M Type B carbon steel; weld longitudinal seams and make end joints by welding, lapping and bolting, or with companion flanges.

B. Breechings Less Than 24 inches in Diameter: Fabricate from hot-dipped galvanized steel sheet, ASTM A653/A653M FS, with G90/Z275 coating; make longitudinal seams using pipe lock or flat lock groove seam and make end joints beaded and crimped.

C. Minimum Metal Thicknesses based on SMACNA (DCS):

1. Sizes up to 12 inches: 18 gauge, 0.0478 inch.

2. Sizes 13 to 24 inches: 16 gauge, 0.0598 inch.

3. Sizes 25 to 36 inches: 14 gauge, 0.0747 inch.

D. Provide adjustable self-actuating barometric draft dampers, where indicated on drawings, full size of breeching.

E. Provide cleanout doors of same gauge as breeching where indicated on drawings.

F. Reinforcing: Provide angle frames for rectangular breeching and flanged girth joints or angle frames for round breeching in accordance with SMACNA (DCS), at following intervals:

1. Sizes up to 30 inches: No reinforcing required.

2. Sizes 31 to 36 inches: 1-1/2 by 1-1/2 by 3/16 inches, at 60 inch centers.

G. Fabricate breeching fittings to match adjoining breechings. Fabricate elbows with centerline radius equal to breeching width. Limit angular tapers to 20 degrees maximum.

2.03 MANUFACTURED BREECHINGS

A. Provide factory-built, modular connector and manifold system, tested to UL 103 with positive pressure rating.

B. Assembly to be UL listed for use with building equipment in accordance with NFPA 211.

Upgrade 235100 - 3 Breechings, Chimneys, and

Stacks

C. Design, fabricate, and install gastight to prevent products of combustion from leaking into building.

1. Securely connect inner joints, and seal with factory-supplied overlapping V-bands and appropriate sealant in accordance with manufacturer's instructions.

2. Design system to compensate for all flue-gas-induced thermal expansion.

2.04 TYPE B DOUBLE WALL GAS VENTS

A. Fabrication: Inner pipe of sheet aluminum, and outer pipe of galvanized sheet steel, tested in compliance with UL 441.

B. Electrically Actuated Vent Dampers: Same size as draft hood collar, constructed of stainless steel or galvanized steel, with corrosion-resistant components, in compliance with ANSI Z21.66.

2.05 INDUCED DRAFT FANS

A. Mechanical Draft Induction Type:

1. Fan: Forward curved venturi type, tested to UL 378, with shaded pole, sleeve bearing motor.

B. Induced Draft Type:

1. Fabrication: Forward curved fan and scroll of mild steel with direct drive shaded pole motor with ball bearings, internal cooling fan, stainless steel shaft, and internal centrifugal switch, tested to UL 378.

C. Electrical Characteristics:

1. Wiring Terminations: Provide terminal lugs to match branch-circuit conductor quantities, sizes, and materials indicated. Enclose terminal lugs in terminal box sized to NFPA 70.

PART 3 EXECUTION

3.01 INSTALLATION

A. Install in accordance with manufacturer's instructions.

B. Install in accordance with NFPA 54 C. Install breechings with minimum of joints. Align accurately at connections, with internal surfaces smooth.

D. Rigidly support breechings from building structure with suitable ties, braces, hangers and anchors to hold to shape and prevent buckling. Support vertical breechings, chimneys, and stacks at 12-foot spacing, to adjacent structural surfaces, or at floor penetrations. Refer to SMACNA (DCS) for equivalent duct support configuration and size.

E. Pitch breechings with positive slope up from fuel-fired equipment to chimney or stack.

F. Coordinate installation of dampers, and induced draft fans. See Section 260583.

G. For Type B, double-wall gas vents, maintain UL-listed minimum clearances from combustibles.

Assemble pipe and accessories as required for complete installation.

H. Install vent dampers, locating close to draft hood collar, and secured to breeching.

I. Assemble and install stack sections in accordance with NFPA 82, UL Listings, and industry practices. Join sections with acid-resistant joint cement. Connect base section to foundation using anchor lugs.

J. Level and plumb chimney and stacks.

K. Clean breechings, chimneys, and stacks during installation, removing dust and debris.

L. At appliances, provide slip joints permitting removal of appliances without removal or dismantling of breechings, breeching insulation, chimneys, or stacks.

M. Provide minimum length of breeching to connect appliance to chimney. Provide Type B chimney continuously from appliances.

END OF SECTION

235100 - Breechings, Chimneys, and Stacks