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Bronze Gear Pump - N993

Our Bronze Gear Pump N993 is a robust and efficient solution designed for long-lasting performance in various fluid transfer applications. Built with the highest quality bronze and 303 stainless steel shafts, this pump is tailored for durability. The carbon graphite bearings, selected for their wear resistance, contribute significantly to the pump's extended lifespan. 

Positive displacement technology means that for each rotation of the shaft, a specific volume of liquid is moved, ensuring a steady flow rate that is largely independent of back pressure in the discharge line. The pump's flow rate is directly proportional to the shaft speed, allowing for precise fluid handling

Optimal Performance Conditions: We recommend operating this pump within pressure limits of 100 PSI (6.9 bar) for water and non-lubricant fluids, and up to 150 PSI (10.3 bar) for oil and other lubricants. The maximum shaft speed is designed to be 1750 RPM.

Key Features:

  • Rugged, corrosion-resistant bronze construction for longevity
  • Space-efficient close-coupled design for easy integration
  • Strong stainless steel shafts for reliability
  • Quiet and durable bronze helical gears
  • Self-lubricating carbon graphite bearings for low maintenance
  • O-ring cover seal providing superior leak protection
  • Standard Nitrile Lip Seal with fluoroelastomer option available
  • Adaptable for easy field assembly with various motor frames

Additional Pump Options:

  • For AC motor compact units, see our Close Coupled Bronze Adapterless Rotary Gear Pumps
  • For hydraulic motor-driven units, refer to adapter 9960
  • For pedestal pump options with mechanical seals, check out model N3000
  • For durable ductile iron pumps, consider model C993

Drive Assembly:
The pump is directly mounted to the electric motor via a suitable adapter bracket, with a flexible coupling connecting the pump drive shaft to the motor shaft.


Liquid Suitability and Temperature Range:

Our gear pumps handle all liquids compatible with bronze, commonly including water, oil, and mild chemicals with a pH range of 4 to 11. For viscous liquids, reduced shaft speeds of 1140 RPM or lower are recommended. Please consult our factory for detailed guidance. Avoid using the pump with liquids containing solids, abrasives, powders, or paint pigments. The ideal liquid temperature for operation ranges from 32°F to 140°F (0°C to 60°C). Consult our factory for advice on extreme temperatures or to prevent damage from frozen water within the pump. Note that cold oils may become very viscous and could require a slower pump speed or increased power.


Suction Lift Considerations:

It's best to minimize suction lift by installing the pump close to the liquid source. A new gear pump can lift water up to 20 feet (6.1 meters) in the suction line. We advise using a foot valve with a strainer at the start of the suction line to maintain priming and prevent dry running. The suction pipe should at least match the size of the pump's inlet port; for longer runs or more viscous liquids, a larger pipe size is recommended.


Rotation and Relief Valve Information:

If your system includes restrictive devices like valves or nozzles, a relief valve is essential to redirect liquid to the suction side or back to the tank, preventing overpressure. The pump's built-in relief valve is intended for intermittent use to avoid overheating. It acts as a safety mechanism, not a control device. For continuous pressure or flow control, a separate relief valve in the pressure line should be used. The standard factory setting provides counterclockwise shaft rotation from the pump shaft end. Reversing the motor will change the "in" and "out" ports and require adjusting the relief valve, which is always placed on the inlet side for this series. The default pressure setting is 50 PSIG (3.4 bar), adjustable by turning the relief valve screw clockwise to increase the pressure.


Shaft Seals:

The close-coupled gear pumps come standard with a Nitrile lip seal, ensuring compatibility with a wide range of fluids and specific applications. For those requiring enhanced chemical resistance or operating at higher temperatures, an upgrade to a fluoroelastomer seal is available. To request this premium seal option, simply add 'S5' to the pump model number when placing your order.

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