Abstract: An IV fluid flow control device includes a rigid casing defining a flow passage having a fluid entrance and a fluid exit. A rigid, previous base is affixed inside the flow passage of the casing. A flexible, resilient flow regulator is disposed inside the flow passage of the casing adjacent to and upstream of the base. The flow regulator normally has a smaller cross-section than does the flow passage, leaving open space for fluid to pass. A rigid, previous cap is disposed inside the flow passage of the casing adjacent to and upstream of the flow regulator. The cap is axially movable inside the flow passage of the casing. The flow regulator biases the cap against pressure from fluid entering through the fluid entrance. Increases beyond a threshold level in the pressure from fluid entering through the fluid entrance cause axial compression of the flow regulator, thereby expending the transverse cross-section of the flow regulator, resulting in a reduction of the open space for fluid to pass.

Abstract: An intravenous fluid flow control device includes a rigid casing having a fluid entrance and a fluid exit. A portion of the casing has a flow restrictor. A pin is disposed inside the casing and axially movable within the flow restrictor. The pin has an interior passageway and at least one upstream opening for a fluid to pass from the casing fluid entrance to the interior passageway of the pin. The upstream opening is elongated in a direction parallel to a pin longitudinal axis, the pin elongated opening being axially movable within the flow restrictor to variably restrict a flow of the fluid passing through the interior passageway of the pin. The pin has a downstream opening for fluid to pass from the interior passageway of the pin to exit the device. Biasing structure (preferably a spring) biases the pin against a fluid pressure of the fluid entering from the casing fluid entrance to cause the pin elongated opening to move with respect to the fluid restrictor.