Glass fiber reinforced plastic clap door specifications are divided into circular clap door and square clap door, can be designed and manufactured according to the size and shape of the outlet; can be respectively hollow floating slab clap door and flat slab clap door. A one-way valve suitable for pipeline and sewage treatment. It has the function of automatic opening and closing. It has good sealing and anti-backflow performance. The corrosion-resistant and energy-saving side-open flap door of composite material is composed of door plate, door hinge, door seat and seal. The door plate is mounted on the door base through the door hinges. According to the application of domestic pumping stations, there are two kinds of door-shaped circular and rectangular flap doors. Generally, the outlet pipe diameter is less than or equal to 2m (that is, the diameter of 1.6 pump) with circular clap door, larger than the diameter of the rectangular clap door. Supply composite material flap door HDPE flap valve high density polyethylene beat door. The racket door is divided into circular racket door and square racket door, which can be designed and manufactured according to the size and shape of the outlet, and can be divided into hollow float racket door and flat racket door. Composite clap door, glass fiber reinforced plastic clap door, HDPE clap door, high density polyethylene clap door is suitable for pipeline, sewage treatment, river bank drainage pipe outlet of a one-way valve, it has automatic opening and closing function; water stop, anti-reflux performance is good; composite clap door, glass fiber reinforced plastic clap door, HDPE clap door, high density polyethylene. The door is corrosion resistant and easy to install and manage.