The present invention is directed to an improved liquid additive injection pump that of a type wherein a variety of additive volumes may be metered into a fluid stream or fluid source by adjusting the plunger stroke with an easily accessible adjustment bushing without changing or interrupting, the power supplied to the pump during operation. A robust roller bearing drive is used to power the plunger(s) providing fluid suction and discharge as the plunger(s) cycle, while ensuring accurate and reliable additive injection rates. A spring energized seal eliminates overtightened packing by field technicians. An easily accessible adjustment bushing allows the user to modify the piston stroke length, thereby increasing, decreasing or stopping the volumetric flow of injected additive into a fluid stream or storage container.

The invention relates to a valve assembly for a diaphragm pump, the valve assembly having an inlet side and an outlet side. A first outlet channel (23) leads from an inlet opening (24) arranged on the inlet side to an outlet opening (25) arranged on the outlet side, and a second outlet channel (26) leads from an inlet opening (27) arranged on the inlet side to an outlet opening (28) arranged on the outlet side. An inlet channel (30) has a first part (31) and a second part (32), the second part (32) having an outlet opening (33), which is arranged on the inlet side, and the first part (31) extending at an angle to the second part (32). An inlet valve body (40) is provided at the outlet opening (33) of the second part (32) of the inlet channel (30), and a first outlet valve body (41) is provided at the outlet opening (25) of the first outlet channel (23). The outlet opening (28) of the second outlet channel (26) is closed and opened either by a second outlet valve body or also by the first outlet valve body (41).

A low-force, non-displacement, micro/miniature valve and/or pump assembly is provided. A tube component having a first side port coupled to an inlet portion and a second side port coupled to an outlet portion can be selectively moved to alternatively couple the side ports to a first or second piston pump chamber. First and second pistons can be actuated after positioning the tube component to either draw in fluid or push out fluid from either the first or second piston pump chambers during each actuation of the pistons. The fluid can be drawn in from a reservoir and can be expelled to a patient for providing a dose of the fluid to the patient.

A pipetting device includes a housing, a valve assembly, and an actuator assembly. The housing includes a tip for receiving a capillary tube. The valve assembly includes a shuttle valve having a filling position and a dispensing position and a valve rod. The actuator assembly includes an actuator, a valve trigger, a piston mount, and an indexing mechanism. The actuator extends from the housing and has a push button coupled to a push rod. The valve trigger being configured to engage the valve assembly and includes an aperture configured to receive the piston mount therein. The indexing mechanism is configured to index a rotated position of the push button to a predefined volume of dispensed fluid.

An automatic bidirectional valve includes: a valve body, a central conduit that crosses the valve body and is provided with a first opening in a first end of the valve body and a second opening made in an opposite second end thereof, and a peripheral conduit made in the valve body, provided with a first opening, made in a portion of the valve body between the first and second ends, and a second opening made in the second end. A first shutter is movable between a closing position and an opening position, a first elastic element configured to generate a force adapted to maintain the first shutter in the closing position, a second shutter movable between a closing position, and an opening position, a second elastic element configured to generate a force to maintain the second shutter in the closing position, and a retaining body fixed to the valve body.

A double-acting reciprocating pump comprises a piston assembly comprising at least one piston disposed within at least one piston cylinder for undergoing opposite reciprocal movements within said at least one piston cylinder, an upper pump chamber disposed above the piston, and a lower pump chamber disposed below the piston. A fluid inlet is fluidically connected to one of the upper and lower pump chambers so as to supply fluid thereto, and a fluid outlet dispensing port is defined within a lower end portion of the double-acting reciprocating pump assembly for permitting fluid to be dispensed out from the double-acting reciprocating pump assembly during both of the opposite reciprocal movements.

A double-acting reciprocating pump comprises a piston assembly comprising at least one piston disposed within at least one piston cylinder for undergoing opposite reciprocal movements within said at least one piston cylinder, an upper pump chamber disposed above the piston, and a lower pump chamber disposed below the piston. A fluid inlet is fluidically connected to one of the upper and lower pump chambers so as to supply fluid thereto, and a fluid outlet dispensing port is defined within a lower end portion of the double-acting reciprocating pump assembly for permitting fluid to be dispensed out from the double-acting reciprocating pump assembly during both of the opposite reciprocal movements.

A pump includes a liquid housing having a liquid chamber with a piston/diaphragm assembly arranged therein that responds to a suction stroke and draws liquid into the liquid chamber, and responds to a pressure stroke and provides liquid from the liquid chamber; and a gas housing having a slide valve assembly separating first and second gas chambers. The slide valve assembly responds to a suction-to-pressure-force at the suction stroke conclusion, changes from a suction-to-pressure stroke state, provides gas from the first to second gas chamber through the slide valve assembly, and provides the pressure stroke so liquid passes from the liquid chamber; and responds to a pressure-to-suction-force at the pressure stroke conclusion, changes from the pressure-to-suction stroke state, provides gas from the second chamber through the slide valve assembly, and provides the suction stroke so liquid is drawn into the liquid chamber.

A fuel pump, is disclosed, including a power group having a housing, a coil, a pole piece and a movable armature; a valve group including a valve body, a plunger connected to the armature, a bushing in which the plunger is disposed, an inlet chamber, an outlet chamber, a pump chamber, an inlet valve disposed between the inlet chamber and the pump chamber and an outlet valve disposed between the pump chamber and the outlet valve; and an inlet filter coupled to a fluid inlet of the valve group. The inlet filter is disposed relative to the coil such that when the fuel pump is disposed within a fuel tank, a bottom of the inlet filter as oriented in the fuel tank is disposed above a fuel level in the fuel tank and the coil is at least partly submerged in the fuel.

A method of driving a pump is used in a pressure-applying apparatus, the apparatus including a flow passage, a pump configured to impart pressure into the flow passage, an opening and closing valve configured to open and close the flow passage, a pressure detector configured to detect pressure in the flow passage, and an atmospheric air open valve configured to open an interior of the flow passage to atmospheric air. The method includes driving the pump after closing the opening and closing valve and opening the atmospheric air open valve, and evaluating a state of the pump, based on one of: the pressure detected by the pressure detector at a time at which a predetermined time period has elapsed after closing the atmospheric air open valve, and a time from closing of the atmospheric air open valve until detection of a predetermined pressure by the pressure detector.