External Gear Pumps

External Gear Pumps

External gear pumps are typically used as lubrication pumps in machine tools, oil pumps in engines and in fluid power transfer units. They can have one or two gears in the pump that drives the liquid. As with all gear pumps, external gear pumps provide a relatively smooth flow of liquid. The two-gear versions of external gear pumps differ from internal gear pumps in that they have two identically sized gears operating next to each other. One gear connected by a drive shaft to a motor, drives the second gear. As the gears unmesh, they create a vacuum that draws in the liquid from an inlet valve. The gears carry the liquid around the casing until they begin to mesh again, forcing the liquid through the outlet valve.

External gear pumps run with close tolerances, allowing them to pump to pressures beyond 3,000 PSI / 200 BAR, making them well suited for hydraulic systems. Their tight internal clearances also provide a more reliable measure of liquid passing through a pump and greater flow control, making them a pump of choice for precise transfer and metering applications requiring the flow of fuels, chemical additives and polymers.

Yet because of their tight tolerances and bearings in the liquid, these pumps are not well suited to transfer abrasive fluids or work in extremely high temperatures.

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Wilden Pumps
Since 1955, Wilden Pumps has been the market leader in air-operated double-diaphragm pumps.



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Viking Pump
Viking Pump provides an unmatched combination of application expertise and positive displacement pumping products to meet your pumping needs.



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Liquiflo Equipment Company is an international company that engineers, manufactures, and markets sealed and mag-drive, positive displacement and centrifugal pumps.



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Liquid Controls
Liquid Controls has been dedicated to providing high quality flow meters and accessories for accurate liquid measurement in both custody transfer and process control applications.



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Red Seal Measurement
Red Seal Measurement systems are specially designed to provide unsurpassed service in the most demanding measurement applications, from refined fuel custody transfer to exacting batching operations in the food and chemical industries.



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Neptune ​metering pumps deliver precise, adjustable flow rates to move a measured volume of liquid over a specified time.



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