... anticorrosion,anti-swing safety CWZ Series Marine smaller ventilating fan 1.GeneralCWZ series marine or navy small-sized ... into two structure types, type I (tube type), type II (porthole type): I tube type for ventilation of short tubes ... join them forcing, not bring the weight of duct on the fans.4.3 After installed the ... 4.5 After the fans wiring, the terminal box should be sealed, avoid the air or ...