A rotary disc valve is used in a fluid delivery system to control flow of fluid between multiple ports of a valve housing. The valve housing may include a valve body and a lid that closes an open end of the valve body. In addition, the valve may include a diverter and seal assembly that are disposed in the valve housing. The diverter is configured to rotate about a rotational axis and to control fluid flow through the valve housing. The seal assembly provides a dynamic seal that is fluid tight within a plane that is perpendicular to the rotational axis. The diverter, the valve body and the seal assembly cooperate to define a fluid passageway that is coaxial with the rotational axis and passes through the seal assembly.

An example valve includes a piston configured to block fluid flow from a first port of the valve to a second port of the valve when the valve is in a closed position; a relief mode spring applying a first biasing force on the piston in a distal direction; a reverse flow spring applying a second biasing force on the piston in a proximal direction, wherein the reverse flow spring is weaker than the relief mode spring; and a pressure setting spring applying a third biasing force on a check element in the distal direction, causing the check element to be seated when the valve is in the closed position.

An example valve includes a piston configured to block fluid flow from a first port of the valve to a second port of the valve when the valve is in a closed position; a relief mode spring applying a first biasing force on the piston in a distal direction; a reverse flow spring applying a second biasing force on the piston in a proximal direction, wherein the reverse flow spring is weaker than the relief mode spring; and a pressure setting spring applying a third biasing force on a check element in the distal direction, causing the check element to be seated when the valve is in the closed position.

A rotary disc valve is used in a fluid delivery system to control flow of fluid between multiple ports of a valve housing. The valve housing may include a valve body and a lid that closes an open end of the valve body. In addition, the valve may include a diverter and seal assembly that are disposed in the valve housing. The diverter is configured to rotate about a rotational axis and to control fluid flow through the valve housing. The seal assembly provides a dynamic seal that is fluid tight within a plane that is perpendicular to the rotational axis. The diverter, the valve body and the seal assembly cooperate to define a fluid passageway that is coaxial with the rotational axis and passes through the seal assembly.

An example valve includes a piston configured to block fluid flow from a first port of the valve to a second port of the valve when the valve is in a closed position; a relief mode spring applying a first biasing force on the piston in a distal direction; a reverse flow spring applying a second biasing force on the piston in a proximal direction, wherein the reverse flow spring is weaker than the relief mode spring; and a pressure setting spring applying a third biasing force on a check element in the distal direction, causing the check element to be seated when the valve is in the closed position.

An example valve includes a piston configured to block fluid flow from a first port of the valve to a second port of the valve when the valve is in a closed position; a relief mode spring applying a first biasing force on the piston in a distal direction; a reverse flow spring applying a second biasing force on the piston in a proximal direction, wherein the reverse flow spring is weaker than the relief mode spring; and a pressure setting spring applying a third biasing force on a check element in the distal direction, causing the check element to be seated when the valve is in the closed position.