This chimney is listed (UL 103TYPE HT) for venting flue gases not exceeding 1000 deg F under continuous operating conditions. In addition, UL has conducted additional tests at 1400 deg F for one hour and 2100 deg F for 10 minutes to verify compliance with UL test standards. The Model HS incorporates a design woven ceramic fiber refractory blanket. Surrounded by two inner walls, this asbestos-free blanket has excellent high temperature stability, so it stays in place. It is noncombustible, thin, and lightweight. As a result, the Model HS chimney pipe features the same small outer dimensions and is compatible with our Model FB. It is light enough to be easily installed by one person. The Model HS blanket exhibits superior resistance to high temperature deterioration. Its insulation has proven so effective that it is used as a fire retardant in aircraft, railroad tank cars, chemical facilities, and commercial buildings. Model HS is built to last with a system combining corrosion resistant stainless steel and sturdy galvanized steel. All this adds up to extra protection for your customers through Amervent’s advanced chimney temperature engineering.