Abstract: A printing fluid delivery system comprising a fluid pump having an inlet and an outlet, a valve connected to the outlet of the fluid pump, and a controller to close the valve while the fluid pump is driven to increase the pressure at the outlet of the fluid pump based on a service condition and to open the valve based on a predefined relief condition to relieve the pressure at the outlet of the fluid pump.

Abstract: A device includes a fluid channel connecting a pair of ports and an attachment feature to attach the device at a dummy cartridge; wherein the pair of ports is dimensioned to mate with fluid feed ports of a printer when the device is attached to the dummy cartridge and the dummy cartridge is inserted in the printer.

Abstract: In an example, a pressure system includes a fluid movement device, a buffer reservoir coupled to the fluid movement device, and a first fluid interface coupled to the buffer reservoir. In that example, the first fluid interface is able to couple to a pressurizable chamber of a print fluid container (that can apply force on a print fluid bag of the print fluid container).

Abstract: A differential pressure sensor is used for measuring or identifying a pressure difference, for example to determine a movement or speed of fluid in a fluid conduit or printer re-circulation conduit. The differential pressure sensor determines the difference between an air pressure and a fluid pressure, wherein the fluid is moving in a flow channel. The flow channel includes a surface conveying a fluid between a first port and second port. An opening in the surface of the flow channel provides a fluid communication between the differential pressure sensor and fluid. Moreover, the sensor is arranged in air communication with the pressure box, such as to allow the differential pressure sensor to identify the pressure difference between the air pressure in the pressure box and the fluid pressure in the flow channel.

Abstract: In an example, a pressure system includes a fluid movement device, a buffer reservoir coupled to the fluid movement device, and a first fluid interface coupled to the buffer reservoir. In that example, the first fluid interface is able to couple to a pressurizable chamber of a print fluid container (that can apply force on a print fluid bag of the print fluid container).

Abstract: In an example, a printer controller is coupled to a fluid pump, a primer pump, and a pressure sensor of a printer, wherein a flow channel provides a fluid communication between the fluid pump and the printhead for enabling fluid recirculation in the printer. The printer controller: activates the fluid pump; activates the primer pump for a first predefined time interval; and identifies or determines a movement of fluid in the flow channel based on the fluid pressure measured by the pressure sensor.

Abstract: A device includes a fluid channel connecting a pair of ports and an attachment feature to attach the device at a dummy cartridge; wherein the pair of ports is dimensioned to mate with fluid feed ports of a printer when the device is attached to the dummy cartridge and the dummy cartridge is inserted in the printer.

Abstract: A printing device comprises a printing fluid supply; a plurality of printheads connected in parallel to the supply by a first flow path and a second flow path; a first fluid pressure source to create a negative fluid pressure between the supply and the first openings; a second fluid pressure source to create a positive fluid pressure between the supply and the second openings; and a controller. Each printhead comprises a closable first opening connected to the first flow path and a closable second opening connected to the second flow path, and has an associated mechanism to increase a fluid pressure in the printhead. Each first opening is to open in response to operation of the associated mechanism. The controller is to identify a first printhead for which printing fluid in the first printhead is to be recirculated; and operate the mechanism associated with the identified printhead.

Abstract: In an example, a printer controller is coupled to a fluid pump, a primer pump, and a pressure sensor of a printer, wherein a flow channel provides a fluid communication between the fluid pump and the printhead for enabling fluid recirculation in the printer. The printer controller: activates the fluid pump; activates the primer pump for a first predefined time interval; and identifies or determines a movement of fluid in the flow channel based on the fluid pressure measured by the pressure sensor.

Abstract: An example printing fluid container (100) comprising a container body (102) defining a cavity (104), and a piston (106) located within the cavity (104), is described. The piston (106) divides the cavity (104) into a first chamber (108) to receive printing fluid and a second chamber (110), fluidically isolated from the first chamber (108), to receive a positively pressurized fluid.

Abstract: A differential pressure sensor is used for measuring or identifying a pressure difference, for example to determine a movement or speed of fluid in a fluid conduit or printer re-circulation conduit. The differential pressure sensor determines the difference between an air pressure and a fluid pressure, wherein the fluid is moving in a flow channel. The flow channel includes a surface conveying a fluid between a first port and second port. An opening in the surface of the flow channel provides a fluid communication between the differential pressure sensor and fluid. Moreover, the sensor is arranged in air communication with the pressure box, such as to allow the differential pressure sensor to identify the pressure difference between the air pressure in the pressure box and the fluid pressure in the flow channel.

Abstract: A printing fluid cartridge (104) for a pumped printing fluid system containing a pump (110) is described, the printing fluid cartridge (104) comprising a housing (120) defining an interior chamber (122); a collapsible bag (124) within the chamber for holding a supply of printing fluid (126); and a fluid connection member (106) for forming a fluid connection between the collapsible bag (124) and an upstream side of the pump (110). The housing (120) includes a structure allowing the application of manual pressure to the collapsible bag (124) to urge printing fluid out of the collapsible bag through the fluid connection member (106) to the upstream side of the pump (110) to displace air (130) in the fluid connection member (106) and the pump (110).

Abstract: A printing device comprises a printing fluid supply; a plurality of printheads connected in parallel to the supply by a first flow path and a second flow path; a first fluid pressure source to create a negative fluid pressure between the supply and the first openings; a second fluid pressure source to create a positive fluid pressure between the supply and the second openings; and a controller. Each printhead comprises a closable first opening connected to the first flow path and a closable second opening connected to the second flow path, and has an associated mechanism to increase a fluid pressure in the printhead. Each first opening is to open in response to operation of the associated mechanism. The controller is to identify a first printhead for which printing fluid in the first printhead is to be recirculated; and operate the mechanism associated with the identified printhead.

Abstract: A printing fluid cartridge (104) for a pumped printing fluid system containing a pump (110) is described, the printing fluid cartridge (104) comprising a housing (120) defining an interior chamber (122); a collapsible bag (124) within the chamber for holding a supply of printing fluid (126); and a fluid connection member (106) for forming a fluid connection between the collapsible bag (124) and an upstream side of the pump (110). The housing (120) includes a structure allowing the application of manual pressure to the collapsible bag (124) to urge printing fluid out of the collapsible bag through the fluid connection member (106) to the upstream side of the pump (110) to displace air (130) in the fluid connection member (106) and the pump (110).

Abstract: An example device in accordance with an aspect of the present disclosure includes a first reservoir for a printable composition, a pump fluidically coupled to the first reservoir and a second reservoir, a sensor, and a controller. The controller is to identify first and second reservoir statuses based on the sensor.

Abstract: An example device in accordance with an aspect of the present disclosure includes a first reservoir for a printable composition, a pump fluidically coupled to the first reservoir and a second reservoir, and a valve to prevent backflow from the second reservoir to the pump. The valve is to selectively isolate the second reservoir from the pump based on a threshold pump pressure under which the valve is to close.

Abstract: An example printing fluid container (100) comprising a container body (102) defining a cavity (104), and a piston (106) located within the cavity (104), is described. The piston (106) divides the cavity (104) into a first chamber (108) to receive printing fluid and a second chamber (110), fluidically isolated from the first chamber (108), to receive a positively pressurized fluid.

Abstract: A printing apparatus, a printing system and a method are disclosed. The method of moving printing fluid within a printing apparatus includes selectively providing a first pressure difference between a first reservoir and a second reservoir by a differential pressure system to cause the printing fluid to move from the first reservoir through a printing fluid applicator to the second reservoir. The method also includes selectively providing a second pressure difference between the first reservoir and the second reservoir by the different pressure system to cause the printing fluid to move from the second reservoir through the printing fluid applicator to the first reservoir.

Abstract: An example device in accordance with an aspect of the present disclosure includes a first reservoir for a printable composition, a pump fluidically coupled to the first reservoir and a second reservoir, a sensor, and a controller. The controller is to identify first and second reservoir statuses based on the sensor.

Abstract: An example device in accordance with an aspect of the present disclosure includes a first reservoir for a printable composition, a pump fluidically coupled to the first reservoir and a second reservoir, and a valve to prevent backflow from the second reservoir to the pump. The valve is to selectively isolate the second reservoir from the pump based on a threshold pump pressure under which the valve is to close.