Pump authority switching apparatus for a fluid distribution system

A fluid distribution system comprising:

• a boost supply which provides a fluid flow;
• a fluid metering system positioned downstream of the boost supply, the fluid metering system configured to supply fluid at a minimum pressure to a downstream device;
• a main fluid pump configured to supply at least a portion of the fluid flow to the fluid metering system, a shut-off valve positioned upstream of a main fluid pump inlet;
• an actuation system positioned downstream of the boost supply, the actuation system configured to supply fluid to one or more hydraulically-operated devices;
• an actuation pump configured to supply at least a portion of the fluid flow to the fluid metering system and to the actuation system;
• a first valve positioned between the actuation pump and the fluid metering system, wherein the first valve and the shut-off valve are operable to switch between the main fluid pump and the actuation pump as a source of fluid supply to the fluid metering system;
• wherein the main fluid pump comprises a centrifugal pump.

A fluid distribution system comprising:

• a boost supply which provides a fluid flow;
• a fluid metering system positioned downstream of the boost supply, the fluid metering system configured to supply fluid at a minimum pressure to a downstream device;
• a main fluid pump configured to supply at least a portion of the fluid flow to the fluid metering system, a shut-off valve positioned upstream of a main fluid pump inlet;
• an actuation system positioned downstream of the boost supply, the actuation system configured to supply fluid to one or more hydraulically-operated devices;
• an actuation pump configured to supply at least a portion of the fluid flow to the fluid metering system and to the actuation system;
• a first valve positioned between the actuation pump and the fluid metering system, wherein the first valve and the shut-off valve are operable to switch between the main fluid pump and the actuation pump as a source of fluid supply to the fluid metering system;
• wherein the first valve and the shut-off valve are both controlled electrically by respective electro-hydraulic servo valves.

A fluid distribution system comprising:

• a boost supply which provides a fluid flow;
• a fluid metering system positioned downstream of the boost supply, the fluid metering system configured to supply fluid at a minimum pressure to a downstream device;
• a main fluid pump configured to supply at least a portion of the fluid flow to the fluid metering system, a shut-off valve positioned upstream of a main fluid pump inlet;
• an actuation system positioned downstream of the boost supply, the actuation system configured to supply fluid to one or more hydraulically-operated devices;
• an actuation pump configured to supply at least a portion of the fluid flow to the fluid metering system and to the actuation system;
• a first valve positioned between the actuation pump and the fluid metering system, wherein the first valve and the shut-off valve are operable to switch between the main fluid pump and the actuation pump as a source of fluid supply to the fluid metering system;
• wherein the first valve is configured to maintain a first constant pressure drop across the fluid metering system.