Gear Pumps

Filter Press Gear Pump NL4000L

Compact by design, the energy efficient positive displacement NL Series? helical gears with tight tolerances reduce mechanical losses and internal slippage to maximize volumetric efficiency; enabling self-priming capabilities providing you an economical lead-free filter press pump solution

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SKU: NL4000L Category:



  • All pump components are lead free and corrosion resistant
  • PEEK and stainless steel gears for increased durability
  • Helical gears reduce noise levels
  • While improving quality we have maintained value and affordability
  • Braided compression packing seals (with Teflon? dispersion) standard


Either direct drive with flexible coupling or pulley drive can be used. Make sure both flexible coupling halves are properly aligned. When using a pulley, do not over tighten the belt. Also, to absorb belt side thrust at higher pressures and larger size pumps, an external ball bearing support is recommended – consult factory.


Service life will be increased substantially if the liquid pumped is clean and has some degree of lubricity. These positive displacement pumps have tight tolerances. Fine abrasives like sand, silt, or powders in suspension will accelerate pump wear and reduce throughput. Liquids compatible with Lead Free Alloy and stainless steel can be pumped providing proper seal has been specified (see chemical compatibility or check factory). No carbon bearings used. When possible, flush the pump after each usage. Temperature extremes are detrimental to service life and should be avoided. Basic metals of construction allow a temperature range of -40?F to 400?F. Some lip seal elastomers have a limit of 212?F. (see engineering data or check factory). Allowing a liquid to freeze in the pump can cause damage.


Close tolerances and the positive pumping action make the rotary gear pump capable of lifting water on the suction side as high as 20 feet. Though gear pumps are self priming, a foot valve is recommended. If possible, wet the gears with liquid to be pumped for the first dry start. Liquid retained in the system and gear chambers serves to ?wet? the pump on subsequent starts.

*For pressures over 100 psi, the above selections are suitable for pumping fluids with lubricity (e.q. oils, polymers). Service life will decrease for fluids without lubricity (e.q. water, solvents).