The CZF series marine axial fan adopts a welded steel plate structure for the casing, with anti-corrosion treatment on the surface. The inlet and outlet ends of the casing are equipped with flanges for bolt connection with the inlet and outlet ducts. The casing can be made into an integral or axially open structure as needed. An open casing is a type of casing where the impeller and motor are installed on a half casing that can be opened, making it convenient for on-site maintenance and component replacement.