This publication applies to cylinder gas-pressure regulators; pressure regulators with integrated flowmeter devices; medical gas flowmetering devices (flowmeters); pressure regulator/flowmeter and pressure regula-tor/flowgauge combinations; and orifice flow selectors used in the administration of medical gases for treatment, management,diagnostic evaluation, and care of patients. A pressure regulator and flowmeter used in combination shall meet the minimum requirements for each device.