Abstract: A fluid-actuated squeeze valve is provided for use where leak-tight operation and/or very rapid valve closure characteristics are required. The valve comprises an annular valve body with a generally cylindrical open-ended bore for receiving the frusto-conical end portions of two, axially aligned, opposed end plugs. An annular clearance is provided between the end portions and the bore wall for receiving an elastomeric sleeve. Each end plug is provided with an axially extending bore for passage of process fluid which communicates with angled passageways extending from the bore to the slant surface of a respective frusto-conical end portion. The smaller truncated end surfaces of the two opposed end portions are spaced apart axially to define a narrow gap therebetween. Fluid pressure is exerted through an access port in the valve body to actuate the valve by causing the elastomeric sleeve to press against the end portions. Means for operating the valve in response to system pressure parameters are described.

Abstract: Method and apparatus for automatically pipetting reagents which avoid contamination of the reagents. The reagents are withdrawn from a reagent bottle via a pipette tip which is unique to a particular reagent. The pipette tip is moved to a cuvette where the reagent is dispensed and then returned to rest in the cap of the reagent bottle. The apparatus for carrying out the method includes a pump, pipette pick-up device, reagent bottle cap and bottle rack.