A pump cassette is disclosed. The pump cassette includes a housing having at least one fluid inlet line and at least one fluid outlet line. The cassette also includes at least one reciprocating pressure displacement membrane pump within the housing. The pressure pump pumps a fluid from the fluid inlet line to the fluid outlet line. A hollow spike is also included on the housing as well as at least one metering pump. The metering pump is fluidly connected to the hollow spike on the housing and to a metering pump fluid line. The metering pump fluid line is fluidly connected to the fluid outlet line.

To manufacture a diaphragm pump with higher reliability in which the mechanism of a main valve is simplified without a pilot chamber. A diaphragm pump 10 includes paired diaphragms 34 and 44 that define pump chambers 36, 46 and air chambers 32, 42, a main body unit 20 that slidably supports a center rod 120 at a central portion of each diaphragm 34, 44 so as to be capable of reciprocating the center rod 120, and a valve body 80 that houses a spool 100 that switches supply of a fluid to the air chambers 32 and 42 so as to reciprocate the center rod 120, the valve body 80 including a sleeve 84, and the spool 100 that is disposed inside the sleeve 84 to be reciprocated in an axial direction, wherein the spool 100 is composed of a disc-shaped portion S3, a disc-shaped portion S2, and a disc-shaped portion S1, and a surface area of each disc-shaped portion that receives a compressed air pressure has a relationship that an upper side of the disc-shaped portion S3>a lower side of the disc-shaped portion S2>an upper side of the disc-shaped portion S1.

A blood treatment system includes (i) a blood pump including a first blood pump chamber operable with a first inlet valve and a first outlet valve, and a second blood pump chamber operable with a second inlet valve and a second outlet valve; (ii) an arterial blood line; (iii) a dialyzer placed in fluid communication with the arterial blood line, wherein the blood pump is provided along the arterial blood line upstream of the dialyzer; and (iv) a venous blood line extending downstream from the dialyzer. The system also includes a processor configured to sequence the first and second blood pump chambers so as to achieve a pulsatile pattern of filling the first and second blood pump chambers and an at least substantially constant pattern of discharging blood from the first and second blood pump chambers to the dialyzer.

An automated fluid transfer system and method allows a person to pour fluid, such as used motor oil, into a collection pan which automatically pumps the fluid to a bulk storage tank, without secondary containment in the collection pan. The system utilizes an air powered pump, thereby eliminating the use of electricity which creates fire and explosion hazards. A float rises and falls in response to fluid in the pan, so as to automatically turn on and turn off the pump. An alternative manual mode is provided to allow fluid to be sucked by the pump from a container directly into the bulk storage tank, while bypassing the collection pan.

Provided are sampling pumps and gas analyzers using the sampling pumps. The sampling pump may include at least one reciprocating pump set and a control system. Each reciprocating pump set can include two reciprocating pumps. The control system can output drive signals for controlling reciprocating drawing and compressing operations of the reciprocating pumps, where the control system may be designed to output the drive signals that cause the two reciprocating pumps within the same set to provide opposing impact directions at the same time.

An air-operated pump, such as an air-operated diaphragm pump, includes a pump body, a process liquid pathway defined at least in part by the pump body, and an air pathway defined at least in part by the pump body, where the process liquid pathway and air pathway are fluidly separated from one another within the pump body. The pump further includes a leak detection and containment assembly integrated with the pump body and having a process liquid sensor configured to sense process liquid leaked from the process liquid pathway into the air pathway, and a shutoff valve communicatively coupled to the process liquid sensor and configured to close in response to the process liquid sensor sensing a process liquid leak to contain the leaked process liquid within the pump body and the assembly.

A positive displacement pump includes a housing surrounding a drive chamber and a diaphragm compartment. A drive element is inside the drive chamber. A diaphragm is inside the diaphragm compartment and divides the diaphragm compartment into a fluid chamber and a cavity. A shaft connects the drive element and the diaphragm. A breather valve is fluidically connected to the cavity and is configured to allow air to exit the cavity. The cavity is fluidically disconnected from the drive chamber.

The invention relates to a low-pressure starter device for pneumatic pumps with a pivoting directional air-control valve, characterised in that the low-pressure starter system consists of a retractable push piston actuated by a variable-tension spring that exerts pressure on the shaft of a pivoting element of the body of the directional valve, during start-up, in an end operating positions, said device being formed by a retractable piston, a sealing gasket, a spring and a spring stop.

Embodiments of the present invention relate generally to certain types of reciprocating positive-displacement pumps (which may be referred to hereinafter as “pods,” “pump pods,” or “pod pumps”) used to pump fluids, such as a biological fluid (e.g., blood or peritoneal fluid), a therapeutic fluid (e.g., a medication solution), or a surfactant fluid. The pumps may be configured specifically to impart low shear forces and low turbulence on the fluid as the fluid is pumped from an inlet to an outlet. Such pumps may be particularly useful in pumping fluids that may be damaged by such shear forces (e.g., blood, and particularly heated blood, which is prone to hemolysis) or turbulence (e.g., surfectants or other fluids that may foam or otherwise be damaged or become unstable in the presence of turbulence).

Embodiments of the present invention relate generally to certain types of reciprocating positive-displacement pumps (which may be referred to hereinafter as “pods,” “pump pods,” or “pod pumps”) used to pump fluids, such as a biological fluid (e.g., blood or peritoneal fluid), a therapeutic fluid (e.g., a medication solution), or a surfactant fluid. The pumps may be configured specifically to impart low shear forces and low turbulence on the fluid as the fluid is pumped from an inlet to an outlet. Such pumps may be particularly useful in pumping fluids that may be damaged by such shear forces (e.g., blood, and particularly heated blood, which is prone to hemolysis) or turbulence (e.g., surfectants or other fluids that may foam or otherwise be damaged or become unstable in the presence of turbulence).