Abstract: An intravenous metering device is provided which includes an air retention chamber in downstream fluid communication with a source of fluid and in upstream fluid communication with a pumping chamber. A first valve is provided between the air retention chamber and the pumping chamber to control access to the pumping chamber. A second valve is provided to control the exit of fluid from the pumping chamber. The valves include a shared diaphragm portion. A safety mechanism as provided to prevent accidental free flow of fluid through the metering device. In a first preferred embodiment of a safety mechanism, a gradually tapered priming stem is provided attached to the diaphragm portion of the second valve. In a second preferred embodiment of a safety mechanism, a priming stem is provided attached to the diaphragm portion of the second valve and a priming stem release mechanism is further provided.