Security Chimneys



The ASHT+, with its double-wall all-stainless-steel chimney and exclusive Secure Plus insulation, minimizes heat loss through the chimney walls, and can withstand the intense heat. The free-floating inner lining is attached only to the male coupler at the top, expanding and contracting freely with temperature fluctuations. The external casing of the Secure Temp ASHT+ carries the structural load.


The Secure Temp ASHT+ high-temperature chimney is certified by Intertek Testing (Warnock Hersey) to UL-103HT standards for all diameters of 5, 6, 7, 8 and 10 inches. Secure Temp ASHT+ has a temperature rating of 650°C (1200°F); max. continuous, 760°C (1400°F) brief forced fired; and 1150°C (2100°F) 3 x 30 minutes, tested.


Security Chimneys has been an innovator in the venting field and a market leader in North America since 1960. Instrumental in the company’s growth has been an ongoing focus on product improvement and the introduction of innovative products. This drive for excellence has given rise to the Secure Temp ASHT+, one of the most popular lines of venting products in North America. This high-quality product ensures that end-users benefit
from maximum safety and proven corrosion protection.


The use of stainless steel, selected for its resistance to high temperatures and corrosion, lends outstanding durability to the Secure Temp ASHT+ high-temperature chimneys. All chimneys feature 1 inch of superior-quality, high-density Secura Plus insulation. This exclusive insulationg keeps the temperature of the outer casing relatively low, keeping safety features as simple as possible.

  • Twist-Lock stainless steel coupler system with 1-inch overlap
  • Stainless steel inner lining
  • One inch of exclusive Secura Plus insulation
  • Fast venting of combustion products
  • Stainless steel outer casing
  • Inner liner attached only to the male coupler
  • Lightweight – 6-inch diameter, 5.2 lb. per linear foot
  • Twist-lock assembly for fast, easy and secure installation—no screws or other attachments required
  • Double-lapped flue seam provides radial expansion with the highest level of durability
  • Smooth finish for safe handling during installation
  • Secura Plus™ insulation, pressure-packed to increase flue temperatures for faster start-up, better draft and improved performance
  • Available in 5″ to 10″ inside diameters
  • 2″ safety clearance from combustible materials
  • Available in 8″, 12″, 18″, 24″, 36″ and 48″ lengths
  • All installation accessories made from aluminum-zinc coated steel to prevent rusting
  • Lengths also available in aluminum-zinc coated steel exterior casing for cost savings
  • Tested and listed to UL-103HT
  • Limited lifetime warranty

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ASHT – Interior installation on a wood stove using a finishing supportASHT – Interior installation to a stove in a mobile home
ASHT – Interior installation to a furnaceASHT – Exterior installation in an accessible chase


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