A piston pump is disclosed suitable to be installed on machines for dispensing fluid products, comprising a jacket, a piston device mobile with alternate motion inside said jacket and comprising a rod and a head. The pump also comprises a pipe for fluids to enter and a pipe for fluids to exit, said pipes being disposed on the same side of the jacket and on opposite sides with respect to the piston device.

A piston pump is disclosed suitable to be installed on machines for dispensing fluid products, comprising a jacket, a piston device mobile with alternate motion inside said jacket and comprising a rod and a head. The pump also comprises a pipe for fluids to enter and a pipe for fluids to exit, said pipes being disposed on the same side of the jacket and on opposite sides with respect to the piston device.

[Problems] To provide a driving method for a metering pump, a driving apparatus for a metering pump, a vaporizer and an anesthesia apparatus which are capable of suppressing a pulsation in the metering pump, and lowering the costs and reducing the sizes of the vaporizer and the anesthesia apparatus.

[Means for solving the Problems] A metering pump 16 is joined to the stepping motor 15, includes an eccentric mechanism converting a revolving motion of the stepping motor 15 into a reciprocating motion of a plunger 16A, and makes a constant liquid delivery by sucking and discharging an anesthetic agent through variations in the cubic volume of a cylinder 16D caused by the reciprocating motion of the plunger 16A. The control section 12: calculates a suction and discharge cycle T of the metering pump 16 on the basis of a set anesthetic-gas concentration and a fresh-gas flow rate; sets a discharge period T2 of the cycle T to be longer than a suction period T1 of the cycle T; and controls the revolution speed of the stepping motor 15 so that the travelling speed of the plunger 16A is kept constant during the discharge period T2.

[Problems] To provide a driving method for a metering pump, a driving apparatus for a metering pump, a vaporizer and an anesthesia apparatus which are capable of suppressing a pulsation in the metering pump, and lowering the costs and reducing the sizes of the vaporizer and the anesthesia apparatus.

[Means for solving the Problems] A metering pump 16 is joined to the stepping motor 15, includes an eccentric mechanism converting a revolving motion of the stepping motor 15 into a reciprocating motion of a plunger 16A, and makes a constant liquid delivery by sucking and discharging an anesthetic agent through variations in the cubic volume of a cylinder 16D caused by the reciprocating motion of the plunger 16A. The control section 12: calculates a suction and discharge cycle T of the metering pump 16 on the basis of a set anesthetic-gas concentration and a fresh-gas flow rate; sets a discharge period T2 of the cycle T to be longer than a suction period T1 of the cycle T; and controls the revolution speed of the stepping motor 15 so that the travelling speed of the plunger 16A is kept constant during the discharge period T2.

A pump for the transfer a predetermined total volume of fluid from a pump inlet to a pump outlet in a unit of time is calibrated by deriving a count of the number of times a volume of the fluid is transferred from a pump inlet to a pump outlet in a unit of time; and adjusting the number of times the volume is transferred in a unit of time until the derived count is substantially equal to a predetermined threshold value.

A fluid delivery apparatus includes controller hardware, a diaphragm pump, a positive displacement pump, and a fluid conduit extending between the diaphragm pump and the positive displacement pump. During operation, and delivering fluid to a downstream recipient, the controller hardware draws fluid into a chamber of the diaphragm pump from a fluid source container. The controller hardware applies pressure to the chamber of the diaphragm pump to output the fluid in the chamber of the diaphragm pump downstream through the fluid conduit to the positive displacement pump. During application of the pressure to the chamber and outputting the fluid in the chamber of the diaphragm pump downstream, the controller hardware activates the positive displacement pump to pump the fluid from the positive displacement pump to the downstream recipient.

Embodiments of the present disclosure includes a method of calibrating a pump in a system to determine a minimum pump duty cycle needed. The system comprises a pump, a plurality of application lines downstream of the pump, and a flow control device in each application line. The method determines the minimum pump duty cycle to achieve total flow in the system, achieves a minimum pressure in the system, and ensures that the flow control device is not at or beyond a maximum open position.

Embodiments of the present disclosure includes a method of calibrating a pump in a system to determine a minimum pump duty cycle needed. The system comprises a pump, a plurality of application lines downstream of the pump, and a flow control device in each application line. The method determines the minimum pump duty cycle to achieve total flow in the system, achieves a minimum pressure in the system, and ensures that the flow control device is not at or beyond a maximum open position.

Described is a method for regulating a volume of liquid delivered by a peristaltic pump and a peristaltic pump system that can be used to perform the method. The method includes sensing an ambient temperature of the peristaltic pump. The peristaltic pump includes a pump motor. At least one of a motor speed and a motor operation duration is determined from the sensed temperature, a selected volume of liquid to be delivered and a predetermined correspondence of the motor speed to ambient temperature. The pump motor is operated at the determined motor speed or for the determined motor operation duration to deliver the selected volume of liquid from the peristaltic pump.

A rotary pump for a fluid metering system is provided. The rotary pump reciprocates, and is reversed by a signal from a limit switch that is deflected by an actuator arm on a rotating sleeve of the pump system. The rotary pump includes a plunger and optional stopper formed from a two-shot molding process, and including seals overmolded onto the head of the plunger and the head of the optional stopper.