Abstract: A liquid sealed air displacement apparatus may be used in a fluid transfer device to transfer volumes of fluid. The air displacement apparatus may include a piston and a cylinder defining a displacement chamber for receiving the piston. The air displacement apparatus may be used to displace precise volumes of air into the air displacement chamber. Displacing the air creates a negative pressure in the air displacement chamber (i.e., suction), which may cause a precise volume of fluid to be drawn into the fluid transfer device. The piston and the cylinder may define a diametrical clearance for receiving sealing fluid, which may prevent air leakage and wear.

Abstract: A liquid sealed air displacement apparatus may be used in a fluid transfer device to transfer volumes of fluid. The air displacement apparatus may include a piston and a cylinder defining a displacement chamber for receiving the piston. The air displacement apparatus may be used to displace precise volumes of air into the air displacement chamber. Displacing the air creates a negative pressure in the air displacement chamber (i.e., suction), which may cause a precise volume of fluid to be drawn into the fluid transfer device. The piston and the cylinder may define a diametrical clearance for receiving sealing fluid, which may prevent air leakage and wear.

Abstract: The present invention provides systems and methods of dispensing liquids. In one embodiment, the system includes a pump with a removable pump module with at least one displacement piston and at least one piston valve. A motor and base assembly provide the supporting components of the pump which can be used in environments where precise small volumes of ultra-pure liquids must be transferred from a reservoir to a point of use. The preferred embodiment of the system prevents contaminants and air bubbles from being introduced into the liquid to be dispensed by placing a filter across the discharge line downstream from the pump, and providing a separate drawback line for performing the drawback of the liquid in the dispensing nozzle.

Abstract: The present invention provides systems and methods of dispensing liquids. In one embodiment, the system includes a pump with a removable pump module with at least one displacement piston and at least one piston valve. A motor and base assembly provides the supporting components of the pump, which can be used in environments where precise small volumes of ultra-pure liquids must be transferred from a reservoir to a point of use. The preferred embodiment of the system prevents contaminants and air bubbles from being introduced into the liquid to be dispensed by placing a filter across the discharge line downstream from the pump, and providing a separate drawback line for performing the drawback of the liquid in the dispensing nozzle.

Abstract: A rotary reciprocating pumping apparatus is provided with a positive two position adjustment feature which allows the piston stroke to be increased to a maximum and repeatably, automatically, returned to a second calibrated dispensing position. Such rotary reciprocating pump is further provided with an adjustable liquid displacement velocity profile to maintain sufficient velocity of liquid flow at the end of the pump discharge cycle to enable injection of small volumes of liquid through a pump exhaust port, thereby eliminating the inaccurate and time consuming operation of touching off a small volume of liquid as a drop characterizing known rotary reciprocating pumping systems.