A water-inflow prevention device is provided by installing a closing lid 6 for blocking a duct 2 of an air pressure regulating valve 1, which regulates air pressure inside a cabin 101. A buoyant body 9 is attached to the disc-shaped closing lid 6 installed to the duct 2 so as to be rotatable around a rotation shaft 7. The buoyant body 9 receives a buoyant force from water when immersed in the water. Since the side of the closing lid 6 in which the buoyant body 9 is attached is thereby floated in the water, the closing lid 6 automatically rotates around the rotation shaft 7 so as to close a ventilation port 2a.

Embodiments of a flow control apparatus of the present invention generally include a vessel equipped with a pre-filter assembly, a substantially vertical, bottom-feeding liquid inlet line, a vapor space pressure equalization line, and a liquid outlet, wherein the vessel contains a pair of connected, horizontally oriented, O-ring and/or piston ring equipped sealing plates that are designed to rise and fall as a pair in response to gravity provided liquid pressure in the sump of the vessel, whereby an elevation of the sealing plates provides the liquid in fluid communication with the liquid outlet via internal orifices fluidly connected to one or more fluid conduits. Embodiments of a method of using embodiments of an apparatus of the present invention to control liquid flow are also provided.

Embodiments of a flow control apparatus of the present invention generally include a vessel equipped with a pre-filter assembly, a substantially vertical, bottom-feeding liquid inlet line, a vapor space pressure equalization line, and a liquid outlet, wherein the vessel contains a pair of connected, horizontally oriented, O-ring and/or piston ring equipped sealing plates that are designed to rise and fall as a pair in response to gravity provided liquid pressure in the sump of the vessel, whereby an elevation of the sealing plates provides the liquid in fluid communication with the liquid outlet via internal orifices fluidly connected to one or more fluid conduits. Embodiments of a method of using embodiments of an apparatus of the present invention to control liquid flow are also provided.

Embodiments of a flow control apparatus of the present invention generally include a vessel equipped with a pre-filter assembly, a substantially vertical, bottom-feeding liquid inlet line, a vapor space pressure equalization line, and a liquid outlet, wherein the vessel contains a pair of connected, horizontally oriented, O-ring and/or piston ring equipped sealing plates that are designed to rise and fall as a pair in response to gravity provided liquid pressure in the sump of the vessel, whereby an elevation of the sealing plates provides the liquid in fluid communication with the liquid outlet via internal orifices fluidly connected to one or more fluid conduits. Embodiments of a method of using embodiments of an apparatus of the present invention to control liquid flow are also provided.

Embodiments of a flow control apparatus of the present invention generally include a vessel equipped with a pre-filter assembly, a substantially vertical, bottom-feeding liquid inlet line, a vapor space pressure equalization line, and a liquid outlet, wherein the vessel contains a pair of connected, horizontally oriented, O-ring and/or piston ring equipped sealing plates that are designed to rise and fall as a pair in response to gravity provided liquid pressure in the sump of the vessel, whereby an elevation of the sealing plates provides the liquid in fluid communication with the liquid outlet via internal orifices fluidly connected to one or more fluid conduits. Embodiments of a method of using embodiments of an apparatus of the present invention to control liquid flow are also provided.