Where are external gear pump used?

An external gear pump is a type of positive displacement (PD) pump. External gear pumps use the rotating gears to transfer liquids. The rotating gears form a liquid seal with the pump casing and create a vacuum at the pump inlet, fluid drawn into the pump, is enclosed within the cavities of the rotating gears and transferred to the discharge. External gear pump provides smooth pulse-free flow proportional to the rotational speed of its gears.

External gear pump is deisgned with safety valve for protecting against overload. The full return flow pressure is 1.5 times higher than the rated exhaust pressure of the pump. external gear pump safety valve can be adjusted within the allowance of exhaust pressure range according to circumstance. But please noted the external gear pump safety valve can not be applied pressure reducing valve for long time. You may install pressure reducing valve separately on pipe line if needed.

The design of external gear pump can use circular arc gear, helical gear or herringbone gear. The design of helical gears can reduce the noise and vibration of the pump, because the teeth will gradually mesh and separate during the rotation process. The advantage of spur gears is that they can run at very high speed and are easy to manufacture.

External gear pumps are usually used to pump lubricants, oil, light oils, chemical additives, resins or solvents. They are preferred in any application requiring accurate measurement, such as fuels, polymers or chemical additives.

Some normal applications of external gear pumps are:

·       Crude oil or Palm oil

·       Engine oil or lubricating oil in ship building

·       Various fuel oils and lube oils (engine and gear box lubrication systems)

·       Acids and caustic (with stainless steel material)

·       Resins and polymers

·       Alcohols and solvents

·       Chemical mixing and blending

·       Industrial, agricultural and mobile hydraulic applications (tractors, log splitters, lifts, etc.)

·       Chemical additive and polymer metering

·       Asphalt, bitumen ( external gear pump can with heating jacket)

If the medium working temperature more than 120 deg C, we can change the material of the external gear pump, such as stainless steel or cast steel material. Also, we can suitable mechanical seal to meet the high temperture for external gear pump.

External gear pump can transfer the liquid is normaly for 5cst to 1500 cst, if the liquid is more than 1500 cst, some times, we can change the external gear pump speed to transfer the high viscosity liquids.

Please do not hesitated to contact me if you have any questions for the external gear pump, we will always here to help you.