LP series reverse osmosis membrane element is a polyamide composite membrane used for brackish water desalination. It has the characteristics of low pressure operation, high water yield and good salt removal performance. Suitable for desalination treatment of surface water, groundwater, tap water and other water sources with salt content less than 5000ppm, of which 8-inch membrane is mainly used in large and medium-sized chemical, pharmaceutical, food, power plants, electronics plants for process pure water, boiler supply water, etc., can also be used for municipal water desalination and purification treatment. The 4-inch membrane is mainly used in small-scale pure water and ultra-pure water for medicine, food and electronics factories, and can also be used for desalination and purification treatment of water supply stations such as schools and communities.