flue pipeI. Specifications: Length: 1000mm ID: 125mm, 150mm, 175mm, 200mm OD: 175mm,200mm, 225mm, 250mmII. Body: -Outer layer Material: stainless steel Type: SS304/2B Thickness: 0.5mm Hardness: 200HV Tensile strength: 690MPa/mm2 -Inner layer: Material: stainless steel Type: SS304/2B Thickness: 0.5mm Hardness: 177HV Tensile strength: 480MPa/mm2 III. Flame-retardant material -Material: aluminum silicate -Resistance high temperature: 1,200 C