Is Hart & Cooley B-Vent Fire Rated?

No, Hart & Cooley's Type B gas vent does not have a fire rating. Neither do any of our competitors. The standard for developing fire ratings is ASTM E84. The test method provides a consistent, repeatable test method to report flame spread and smoke development for building materials in response to heat and flame. Results may be used as elements of a fire risk assessment.  Underwriter's Laboratories specify the materials that we use for building our B-vent in their Standard 441 for gas vents. These materials have no ability to ignite or to support or sustain combustion. There is no contribution to the fuel supply. Since there is nothing that can bum, the flame spread rating is "0". Since there is no flame, the smoke density development rating is "0".  Hart & Cooley requires the use of our RSA support in the ceiling above a connected appliance. This support is also a fire stop at that location. UL specifies this to be so. We have been selling this UL listed system and having it installed through partitions in buildings that require fire rated assemblies since 1959 without a problem. UL condones this application.  UL has not encouraged us to test with fire rated assemblies since the test would show consumption and degradation of building materials surrounding the B-vent while leaving the metal vent components in place.