Apparatuses, systems, and methods are disclosed for fluid flow control. A container is shaped to receive a liquid, and includes an outlet configured to allow the liquid to exit the container. A valve is configured to control a fluid flow based on a liquid level in the container. An output line coupled to the valve is configured to convey the fluid flow from the valve to a location outside the container. The location outside the container does not receive the liquid directly from the outlet.

There is provided a liquid level control device (20) for location in a vessel to control the liquid level in the vessel. The liquid level control device (20) comprises: a first chamber (22) including: an opening (26) to allow movement of liquid between the first chamber (22) and the vessel; a vent (28) to allow egress of air from the first chamber (22); and an inlet (30) connectable to a liquid source (34); a first flow controller including a first float (36) arranged in the first chamber (22) such that the flow of liquid into the first chamber (22) raises the first float (36) and displaces air in the first chamber (22) via the vent (28), the first flow controller including a first closure member (40) movable to selectively close and open the inlet (30), the first float (36) further arranged in the first chamber (22) such that, in use, when the first float (36) is at a first position when the liquid level in the first chamber (22) is at or below a first predetermined level, the first float (36) positions the first closure member (40) to open the inlet (30) to allow liquid into the first chamber (22) via the inlet (30), and when the first float (36) is at a second position when the liquid level in the first chamber (22) is at or above a second predetermined level, the first float (36) positions the first closure member (40) to close the inlet (30) to block liquid from entering into the first chamber (22) via the inlet (30); and a second flow controller including a second float (42) and further including a second closure member (46) movable to selectively close and open the vent (28), the second float (42) arranged such that, in use, when the second float (42) is in a first position, the second float (42) positions the second closure member (46) to close the vent (28) to block air from flowing from the first chamber (22) via the vent (28) to escape to atmosphere, and when the second float (42) is in a second position, the second float (42) positions the second closure member (46) to open the vent (28) to allow air to flow from the first chamber (22) via the vent (28) to escape to atmosphere, wherein the first and second floats (42) are arranged such that, in use, when the first float (36) is in its second position and the second float (42) is in its first position, air is trapped in the first chamber

There is provided a liquid level control device (20) for location in a vessel to control the liquid level in the vessel. The liquid level control device (20) comprises: a first chamber (22) including: an opening (26) to allow movement of liquid between the first chamber (22) and the vessel; a vent (28) to allow egress of air from the first chamber (22); and an inlet (30) connectable to a liquid source (34); a first flow controller including a first float (36) arranged in the first chamber (22) such that the flow of liquid into the first chamber (22) raises the first float (36) and displaces air in the first chamber (22) via the vent (28), the first flow controller including a first closure member (40) movable to selectively close and open the inlet (30), the first float (36) further arranged in the first chamber (22) such that, in use, when the first float (36) is at a first position when the liquid level in the first chamber (22) is at or below a first predetermined level, the first float (36) positions the first closure member (40) to open the inlet (30) to allow liquid into the first chamber (22) via the inlet (30), and when the first float (36) is at a second position when the liquid level in the first chamber (22) is at or above a second predetermined level, the first float (36) positions the first closure member (40) to close the inlet (30) to block liquid from entering into the first chamber (22) via the inlet (30); and a second flow controller including a second float (42) and further including a second closure member (46) movable to selectively close and open the vent (28), the second float (42) arranged such that, in use, when the second float (42) is in a first position, the second float (42) positions the second closure member (46) to close the vent (28) to block air from flowing from the first chamber (22) via the vent (28) to escape to atmosphere, and when the second float (42) is in a second position, the second float (42) positions the second closure member (46) to open the vent (28) to allow air to flow from the first chamber (22) via the vent (28) to escape to atmosphere, wherein the first and second floats (42) are arranged such that, in use, when the first float (36) is in its second position and the second float (42) is in its first position, air is trapped in the first chamber

A float valve (10) is provided for use with a liquid medium, the float valve having an upright configuration and an inverted configuration. The float valve includes: a housing (12), defining at least one inlet port (20) and at least one outlet port (24); a float assembly (60) movable within the housing; and an auxiliary float member (50) movable within said housing. The float assembly (60) comprises a primary float member (70; 70), different from the auxiliary float member, and a spring element (80). The primary in float member is configured for closing the at least one outlet port when in abutment therewith, the spring element being configured for providing a biasing spring force to the primary float member in a direction towards said at least one outlet port. The auxiliary float member is configured for providing a net upthrust force with respect to the liquid medium under submerged conditions irrespective of whether the float valve is in said upright configuration or in said inverted configuration.

A float valve (10) is provided for use with a liquid medium, the float valve having an upright configuration and an inverted configuration. The float valve includes: a housing (12), defining at least one inlet port (20) and at least one outlet port (24); a float assembly (60) movable within the housing; and an auxiliary float member (50) movable within said housing. The float assembly (60) comprises a primary float member (70; 70), different from the auxiliary float member, and a spring element (80). The primary in float member is configured for closing the at least one outlet port when in abutment therewith, the spring element being configured for providing a biasing spring force to the primary float member in a direction towards said at least one outlet port. The auxiliary float member is configured for providing a net upthrust force with respect to the liquid medium under submerged conditions irrespective of whether the float valve is in said upright configuration or in said inverted configuration.

A drain assembly for a fluid tank having a drain hole therein may include a hollow first member to be coupled with the drain hole, where the hollow first member has at least one opening therein. The drain assembly may further include a hollow second member slidably coupled with the hollow first member and movable along a longitudinal axis of the hollow outer member between first and second positions. The hollow second member may be configured to seal the at least one opening in the hollow first member when in the first position to define an upper spillover level for fluid within the tank, and to unseal the at least one opening in the hollow first member when in the second position to define a lower spillover level for fluid within the tank below the upper spillover level.

A drain assembly for a fluid tank having a drain hole therein may include a hollow first member to be coupled with the drain hole, where the hollow first member has at least one opening therein. The drain assembly may further include a hollow second member slidably coupled with the hollow first member and movable along a longitudinal axis of the hollow outer member between first and second positions. The hollow second member may be configured to seal the at least one opening in the hollow first member when in the first position to define an upper spillover level for fluid within the tank, and to unseal the at least one opening in the hollow first member when in the second position to define a lower spillover level for fluid within the tank below the upper spillover level.

An oil tank for a gas turbine engine includes a top and a bottom disposed vertically beneath the top. An overfill return passage extends from the bottom of the oil tank toward the top of the oil tank. An outlet is formed on the bottom of the oil tank and inside the overfill return passage. A check valve is inside the overfill return passage and is connected to the outlet. The check valve includes a seat circumscribing the outlet and a plug inside the overfill return passage. The plug has a lower density than an oil disposed inside the oil tank. The check valve does not include a spring such that the plug is configured to translate freely inside the overfill return passage.

An oil tank for a gas turbine engine includes a top and a bottom disposed vertically beneath the top. An overfill return passage extends from the bottom of the oil tank toward the top of the oil tank. An outlet is formed on the bottom of the oil tank and inside the overfill return passage. A check valve is inside the overfill return passage and is connected to the outlet. The check valve includes a seat circumscribing the outlet and a plug inside the overfill return passage. The plug has a lower density than an oil disposed inside the oil tank. The check valve does not include a spring such that the plug is configured to translate freely inside the overfill return passage.

TopSink: Liquid Storage Device with Automatic Discharge in High Volume Batches is a liquid storage device that automatically discharges excess liquid in preset volumes. By releasing surplus liquid from below the surface, TopSink prevents air from entering the discharge line, which significantly improves the heador flow forcein the line. With no air in the line, and with the liquid being released at high volumes, the discharged liquid is able to travel a further distanceeven over an inclinewithout external inputs like electricity. This advantage is in contrast with traditional overflow designs, which merely have a standpipe that enables excess water to trickle out of the line as the level rises. This allows air into the system, causing excess water to pool in the line and travel a minimal distance, TopSink solves this problem by releasing the energy of stored water in high volume bursts, from below the liquid's surface.