Feature Flue with various shapes and purposes Easy operation and ejection, low production technical requirement; Mound production with even wall thickness, forming at one time with high product finished rate Smooth and flat surface with low friction coefficient and windage; Light weight, anti-cracking, high tensile resistance with easy transportation and installation Stable in shape, good stability of volume, easy to be constructed and operated Environment-friendly without toxicity, anti-aging, corrosion resistance, vibration absorption and muffling Simple raw material,low cost and convenient to purchase; The position and direction of the flue vent can be arranged freely with easy design and installation Short time for drawing out the forming molds, 20-30 minutes per piece average Less space area demanded during the process Advantages The flue applies in any kinds of building for exhausting gas and smoke. It has advantages by use the GRC materials, like high strength, fireproof and light weight on installation, etc. The size can be adjusted according to the height between each floor and the amount of the gas exhausted. Exhaust Gas Passage With Variable Pressure with double tubes, to avoid the phenomenon of foul air from floor to floor, it is anti-downdraught; check valve is added at the joint. The flue pipes applies for any height between the floors, It can bear the weight by layered installation. Measure the height between external pipe and the roof according to the designs.