Abstract: A non-contacting air seal device is provided in order to reduce or minimize the ingress of external air into a fluid spray apparatus for applying a fluid coating to a moving web in a papermaking machine. The air seal device includes two air seal assemblies located in tandem with convexly curved web facing surfaces arranged offset in a direction of travel of the web and in opposing relation to one another to define an S-shaped sinusoidal path along which the web travels as it passes through the seal device and wraps a portion of each of the convexly curved web facing surface as it either enters into or exits from the fluid spray apparatus. Each air seal assembly includes a roll, a rod, or a shoe that forms the convexly curved surface over which the web passes in a non-contacting manner on an air cushion which also minimizes ingress of both ambient and boundary layer air external to the fluid spray apparatus.