Fluid measuring circuit

Claim 1

A substantially sealed, manually operable liquid measuring circuit particularly adapted to be connected with a liquid transfer circuit and employed for delivering thereto measured quantities of toxic liquids comprising: A. valve means including, 1. a valve housing having means defining therein a first port, a second port disposed in spaced relation with said first port, and a third port disposed in spaced relation with said first and second ports, 2. valve selector means movably seated within said housing and repositionable from a first position, wherein said selector means serves to connect said first port in communication with said second port, to a second position, wherein said selector means serves to interrupt communication between said first and second port, and thence to a third position, wherein said selector means serves to connect said first port in communication with said third port, and 3. manually operable valve actuating means including a manually displaceable, pivotally supported handle projected from said valve housing and connected with said valve selector means for selectively repositioning said valve selector means from said first position to said second position, and thence to said third position; B. means for continuously applying a vacuum to said valve means including a first conduit connected in communication with said first port and adapted to be connected with the low-pressure side of a liquid transfer pump of a liquid transfer circuit; C. a holding tank adapted to receive and confine therein a measurable quantity of liquid; D. means for delivering a quantity of liquid to the holding tank including, 1. a tubular member having a first end portion connected in communication with the holding tank and a second end portion adapted to be connected in communication with a container confining therewithin a quantity of liquid maintained under ambient atmospheric pressure, and 2. a second conduit connected between said holding tank and said second port through which said second port communicates with said holding tank for evacuating the interior of said holding tank when said first and second ports are connected in communication; E. liquid discharge means including, 1. a third conduit connected between said holding tank and said third port through which said third port communicates with said holding tank for discharging a measured quantity of liquid from said holding tank to said first conduit when said first and third ports are connected in communication, and 2. means including a pressure relief circuit connected with said holding tank for introducing atmospheric pressure into said holding tank in response to a repositioning of said valve selector means to said third position; and F. means including a sight-gauge mounted on said holding tank for continuously indicating the quantity of liquid confined therein.