Flow metering sight glass

Claim 1

A flow metering and flow indicating sight glass for use in a plumbing fixture having an open-ended bore extending completely therethrough, and with which input and outlet passages communicate at positions intermediate the axial ends of said bore, said sight glass including: a solid cylinder of transparent glass-like material receivable within said bore in sealed relation therewith; said solid cylinder having axially opposed end faces extending transversely of the longitudinal axis of said cylinder, at least one of said end faces providing a viewing face through which the interior of said solid cylinder can be viewed; a metering passage providing a metering orifice formed within said solid cylinder and for communication with said inlet passage of said fitting; and a cavitation chamber formed directly within said solid cylinder and into which said metering passage discharges, said cavitation chamber being formed for communication with said outlet passage of said fitting; said metering passage and said cavitation chamber being arranged in series relationship, and extending through the body of said solid cylinder transversely to the longitudinal axis thereof; whereby the presence of fluid exiting said metering passage can be visually confirmed by inspection through said viewing face, and, the presence of actual flow-through said metering passage can be visually confirmed by inspection through said viewing face of cavitation occuring in said cavitation chamber of fluid exiting said metering passage.