Vegetable greenhouses are not limited to seasons as compared to vegetables grown in the open air in the field. And open-air planting, not only seasonal limitations have a variety of adverse weather effects, so the yield and quality can not be guaranteed. Vegetable greenhouses are not limited by seasons, but have the characteristics of breaking time difference, space difference and region difference. Then build a vegetable greenhouse is generally with what specification what good greenhouse tube? Common vegetable greenhouses are cold shed, arch pole and other main materials used pipe is usually hot galvanized round pipe, 6 meters fixed length, 25 or 32 specifications for the common. Hot-dip galvanizing good, from the zinc layer thickness, hot-dip galvanizing is much thicker than electroplating, so corrosion resistance is better. Oval greenhouse pipe and plum greenhouse pipe is just two years into the rise of products, it is better than the round greenhouse pipe firmness, but slightly higher cost. Commonly used specifications are: 4.2 m, 4.5 m, 5 m, 6 m, 7 m, 7.2 m, 7.3 m, 7.5 m, 8 m, 9 m, 12 m, etc. . Diameter according to the size of the shed to determine, in general, not more than 50 mm, wall thickness of about 2.5 can be used according to the situation, of co, the higher the more solid.