UL 441
Standard for Gas Vents

DETAILS
Edition Number:11SCC Approved:--
Edition Date:2016-04-08DOD Approved: 1991-09-16
Price Code:CANSI Approved: 2019-08-19
Type:ulstd

  • SCOPE

    1 Scope

    1.1 These requirements cover Types B and BW gas vents and Types B and BW gas vent roof jacks intended for venting gas appliances equipped with draft hoods to burn only gas. Type B vents are also intended for use with other Category I appliances that specify they are for use with Type B gas vents.

    1.2 The gas vents covered by these requirements are intended for installation in accordance with the National Fire Protection Association Standards for Chimneys, Fireplaces, Vents, and Solid-Fuel Burning Appliances, NFPA 211 the National Fuel Gas Code, NFPA 54, the Department of Housing and Urban Development Mobile Home Construction and Safety Standards, Chapter II of 24 CFR, Part 280, the International Mechanical Code, and the Uniform Mechanical Code.

  • TABLE OF CONTENTS
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    • Cover
    • Transmittal
    • Table of Contents
      • Body
        • INTRODUCTION
          • 1 Scope
          • 2 Components
          • 3 Units of Measurement
          • 4 Undated References
          • 5 Glossary
        • CONSTRUCTION
          • 6 Materials
          • 7 Assembly
          • 8 Caps
          • 9 Firestops
          • 10 Spacers
          • 11 Joints
          • 12 Radiation Shields
          • 13 Roof Assemblies
          • 14 Roof Jacks
          • 15 Fittings
          • 16 Sizes
          • 17 Support Assembly
        • PERFORMANCE
          • 18 General
          • 19 Test Installation
            • 19.1 General
            • 19.2 Type B vents – Form I test structure
            • 19.3 Type B vents – Form II test structure
            • 19.4 Type BW vents – Form III test structure
            • 19.5 Type B Gas vent roof jacks – Forms IV and V test structures
            • 19.6 Type BW gas vent roof jacks – Form VI test structure
          • 20 Temperature Measurement
          • 21 Temperature Test – Structures
            • 21.1 General
            • 21.2 Test type BW gas vent or roof jack test structure Forms III and VI
          • 22 Temperature Test – Gas-Vent Pipe Surfaces
          • 23 Draft Loss and Wind Effects Test
          • 24 Vertical Support Test
          • 25 Strength Test
            • 25.1 General
            • 25.2 Impact test
            • 25.3 Longitudinal force test
          • 26 Wind Load Test
          • 27 Rain Test
          • 28 Crushing Test of Nonmetallic Flue-Gas Conduit
          • 29 Resistance to Action of Acids Test of Nonmetallic Flue-Gas Conduit
          • 30 Freezing and Thawing Test of Water-Absorptive Nonmetallic Materials
          • 31 Cemented Joint Test of Flue-Gas Conduit
          • 32 Sulfuric Acid Extraction Test for Porcelain-Coated Steel Used for Flue-Gas Conduit
        • MARKING
          • 33 General
        • INSTRUCTIONS
          • 34 Installation Instructions