An apparatus for heat stress testing canisters having bodies and valve assemblies, including a heating zone, such as an induction coil system for heating the canisters, and a conveying assembly for conveying the longitudinal axis of each canister in a generally vertical orientation relative to the longitudinal axis of the heating zone, the canisters being positioned partially within the heating zone during the heat testing, such that, each canister's body is positioned substantially inside of the heating zone and each canister's valve assembly is positioned substantially or completely outside of the heating zone.