The Z-Flex Z-Vent 5" to 6" Concentric Increaser (2SVSI0506) is used to upsize a vent system. Recommended for use with vertical vent runs.
Z-Flex Z-Vent Special Gas Vent Single Wall venting is rated AL29-4C and is approved for Category I (vertical only), II, III & IV applications and is designed for use with boilers, high efficiency gas and oil heaters and water heaters where cool flue gases are vented under pressure. Z-Vent contains a built-in, fail-safe gasket and locking band connection. No sealant is required.