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Gear Pump |
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Photo
courtesy of Oberdorfer
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| Gear pumps are positive displacement pumps. Each shaft revolution displaces a definite amount of liquid relatively unaffected by the back pressure in the discharge line. Shaft speed and flow are directly proportional. The most common liquids are water, oil and mild chemicals in the PH-range of 4 to 10. Gear pumps are particularly suitable for viscous liquids up to 100,000 SSU viscosity at reduced shart speeds as low as 200 rpm. Because of their close internal clearances gear pumps are definately not recommended for liquids containing solids, abrasives, powders or paint pigments. If abrasives are unavoidable and the resulting short pump life is acceptable, pump should be driven at slow shaft speed and bronze bearings should be chosen. Best liquid temperature range is from 32F to 140F. More extreme temperatures are possible from -40F to 400F. | |||