Air blocking device(also known as sanitary grade anti backflow floor drain) is designed and manufactured using stainless steel material based on the structural characteristics of imported clean floor drains from abroad and combined with the actual situation in China. It successfully solves technical problems such as dredging, cleaning, water sealing, and sealing. It is a specialized clean leak for various purification plants and clean rooms (GMP certified), mainly used as a specialized clean accessory for chemical, petroleum, power, pharmaceutical, beer, dairy, beverage, and laboratory industries worldwide.