Duravent Stove Pipe DuraTech Elbow Kit 30 Degree SS, 5"

A 30-degree elbow kit is needed when a structural obstruction in the building — such as a rafter, ridgepole, joist, beam, or other framing member — falls in the path of the planned vertical chimney run and the chimney must be offset laterally to route around it. The first elbow angles the chimney away from vertical to clear the obstruction, and the second elbow in the pair returns the chimney back to vertical on the other side. The 360-degree swivel at the base of each elbow allows the offset to be directed in any azimuthal direction as required by the installation geometry, accommodating obstructions in any position relative to the chimney centerline.

The UL 103 standard limits chimney offsets to a maximum of 30 degrees from vertical because larger offsets create horizontal or near-horizontal runs in the chimney that significantly impair draft performance, increase the rate of creosote accumulation, and reduce the chimney system's ability to safely contain and vent the products of combustion from the appliance. A chimney that deviates too far from vertical loses the natural buoyancy-driven draft that moves flue gases upward and out of the building — excessive offset angles create zones where hot flue gases slow, cool, and deposit combustion byproducts at a much higher rate than a predominantly vertical run. The 30-degree limit is a safety and performance threshold established through testing to ensure the chimney system continues to perform safely across its rated operating conditions.

Yes. DuraVent permits two pairs of elbows in a DuraTech chimney installation where the routing geometry of the building requires more than one offset in the chimney run — for example, where the chimney must offset around one obstruction at one level and then offset again to reach the planned termination position. Each pair of elbows consists of two 30-degree elbows — one to angle away from vertical and one to return to vertical — and each pair individually must not exceed the 30-degree offset limit from vertical. Two separate 5DT-E30KSS kits would be required to install two pairs of elbows, as each kit contains only two elbows and one strap for a single elbow pair.

Both the 30-degree and 15-degree elbow kits contain two elbows and one elbow strap and are used in the same way to route around obstructions in a DuraTech chimney run. The difference is the angle of deviation from vertical that each elbow produces — a 30-degree elbow creates a 30-degree angle from the vertical centerline of the chimney, while a 15-degree elbow creates a 15-degree angle. A 30-degree elbow pair creates a larger lateral offset per unit of chimney height in the offset section, allowing the chimney to clear wider or more distant obstructions. The 15-degree elbow kit is used when a shallower, more gradual offset is needed for smaller obstructions or where the installation geometry requires a less aggressive deviation from vertical.

The elbow strap is a structural support strap that provides lateral support for the offset section of the chimney at the elbow location. When two elbows are used to create an offset, the angled section of chimney pipe between them is not self-supporting in the same way as a vertical run — it extends laterally from the vertical centerline and requires additional support to prevent the offset section from sagging or placing excessive lateral stress on the elbow connections over time. The elbow strap is attached between the chimney pipe and the building structure to brace the offset section and maintain correct alignment of the elbows and connecting pipe sections throughout the service life of the installation.

The 5DT-E30KSS elbow kit is one routing component within a complete DuraTech 5-inch chimney installation that also requires straight pipe sections in the appropriate nominal lengths — such as the 5DT-09SS and 5DT-12SS — to build the vertical sections of the chimney run above and below the offset. A ceiling support box or floor support box is required wherever the chimney passes through a floor or ceiling. A roof flashing sized to the roof pitch, a storm collar, and a chimney cap are required to complete the exterior termination of the system. All components must be from the DuraTech 5-inch product family and the total installation must comply with local building codes and the DuraTech installation instructions.