An agricultural air seeder planting unit incorporates control valves that split air flow and change air direction from an air supply to air distribution hoses. The air flow of the control valves is automatically adjusted pneumatically by movement of a piston in response to a total pressure for a uniform velocity air flow from each of the control valves.

There is provided a valve device, including: a housing in which, via a partition wall, a valve chamber is provided below the partition wall and a vent chamber is provided above the partition wall, and a vent hole through which the valve chamber and the vent chamber communicate with each other is provided in the partition wall; and a float valve. A valve seat is formed on a side of the valve chamber of the partition wall, and an opening is provided on an inner side of the valve seat. The opening includes a first opening and a second opening extending outward in a slit shape from an outer periphery of the first opening. A seal part having elasticity that contacts with and separates from the valve seat to close and open the first opening and the second opening, is disposed above the float valve.

Self-closing aquarium valves to consistently acclimate fish to temperature and pH of a new tank with minimal monitoring are described. The self-closing aquarium valve includes a frame, an automatic stopper hingedly connected to the frame that closes automatically, and a hose that provides fluid communication from the new tank to a holding tank, and an adjustable flow control. The self-closing aquarium valve provides consistent acclimation of a fish from the holding tank to a new tank through the adjustable flow control with minimal monitoring with the automatic stopper.

A pneumatic controller for an inline valve includes a manifold with a set screw seated within it, a selector, and a biasing member. The manifold has a low pressure port, a high pressure port, and an actuator port. The selector is movable within the manifold between a first position and a second position, the low pressure port in fluid communication with the actuator port in the first position, the high pressure port in fluid communication with the actuator port in the second position. The biasing member urges the selector towards the first position with a biasing force and is spaced apart from the selector to limit eccentric force exerted on the selector. Inline valves and methods of controlling fluid flow through inline valves are also described.

Self-closing aquarium valves to consistently acclimate fish to temperature and pH of a new tank with minimal monitoring are described. The self-closing aquarium valve includes a frame, an automatic stopper hingedly connected to the frame that closes automatically, and a hose that provides fluid communication from the new tank to a holding tank, and an adjustable flow control. The self-closing aquarium valve provides consistent acclimation of a fish from the holding tank to a new tank through the adjustable flow control with minimal monitoring with the automatic stopper.

The systems and methods of the present disclosure provides an independent passive variable resistor that can be interposed between a fluid reservoir at an inlet pressure and receptacle at an outlet pressure. The resistor can adjust resistance to the pressure difference from the input to the output so that the flow rate through it is a constant rate. The resistor can include a moveable element and a biasing mechanism located in a chamber to create a flow channel. Each side of the moveable element is exposed to the inlet and outlet pressures and moves within the flow channel to modify the resistance of the flow through the chamber in response to the pressures. The balance of these forces determines the position moveable element, which interacts with the fluid channel to determine the flow resistance through variable resistor. The biasing mechanism can provide the necessary pressure to establish equilibrium flow rate.

An agricultural air seeder planting unit incorporates control valves that split flow and change direction from supply to distribution hoses. The flow area of the control valves is automatically adjusted pneumatically by movement of a piston in response to total pressure to provide a uniform velocity flow from each of the control valves.

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.

A control system may comprise a flow control device, wherein the flow control device comprises water floats and gas floats and a regulatory valve connected to the flow control device through a control line. An autonomous flow control device may comprise a housing, one or more floats disposed within the housing, one or more protrusions connected to the outside of the housing, and an outlet disposed in the housing.

The flow rate control device includes a main plate corresponding to an inner diameter and including a through hole which is formed at the center thereof and through which a fluid flows, a sub-plate corresponding to a size of the through hole, disposed in front of the main plate, and applied with a pressure of the flowing fluid, and an expansion and contraction flow path formed to connect the through hole and a circumference of the sub-plate to each other and expanded and contracted by the pressure applied to the sub-plate. The expansion and contraction flow path includes a plurality of holes which are formed in a side surface thereof and through which the flow flows, and has a cross-sectional area changed by the pressure to control a flow rate.