UL 441:11ED 2016-04-08

Foreword
Introduction
1 Scope
2 General
3 Glossary
Construction
4 Materials
5 Assembly
6 Caps
7 Firestops
8 Spacers
9 Joints
10 Radiation shields
11 Roof assemblies
12 Roof jacks
13 Fittings
14 Sizes
15 Support assembly
Performance
16 General
17 Test installation
18 Temperature measurement
19 Temperature test - structures
20 Temperature test - gas-vent pipe surfaces
21 Draft loss and wind effects test
22 Vertical support test
23 Strength test
24 Wind load test
25 Rain test
26 Crushing test of nonmetallic flue-gas conduit
27 Resistance to action of acids test of nonmetallic
    flue-gas conduit
28 Freezing and thawing test of water-absorptive
    nonmetallic materials
29 Cemented joint test of flue-gas conduit
30 Sulfuric acid extraction test for porcelain-coated
    steel used for flue-gas conduit
Marking
31 General
32 Installation instructions

This revision to ANSI/UL 441 dated August 28, 2019 is being issued to update the title page to reflect the most recent designation as a Reaffirmed American National Standard (ANS).

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.