The structure and working principle of oval gear flowmeter - Just Measure it
Tecalemit FMOG OVAL GEAR DEF FLOW METER - National Petroleum Equipment
Turbine Flow Meter Electronic 3/4" 3/4 inch 10-100L/Min Oil Flowmeter Kerosene Gas Methanol Diesel Fuel Flow Digital Meter Oval Gear Gauge LCD BSPT/NPT with Battery: Amazon.com: Industrial & Scientific