Oberdorfer Gear Pump Model# N992N-J08
Pump housings and gears are made of top quality bronze, shafts are
303 stainless steel. Bearings are designed of high performance
carbon-graphite material selected for wear resistance and long service
life.
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.
Recommended pressure limits are 100 PSI for water and non-lubricants,
150 PSI for oil and other lubricants. The maximum shaft speed is 1750
RPM.
FEATURES
- Rugged Corrosion Resistant Bronze Construction
- Compact Close-Coupled Design
- Stainless Steel Shafts
- Durable Bronze Helical Gears Provide Quiet Operation
- Process Lubricated Carbon Graphite Bearings
- O-Ring Cover Seal For Maximum Leak Protection
- Lip Seal or Mechanical Seal
Easy Field Assembly to a Variety of Motor Frames - For Typical DC Motor Pump Units - see N992 DC
- For Compact AC Motor Pump Units see Close Coupled Bronze
Adapterless Rotary Gear Pumps - For Danfoss Hydraulic Motor Driven Pump
Units - See Adapter 9960 For Bonze Pedestal Pumps - See Model N2000 For
Close-Coupled Ductile Iron Pumps - See Model C992
LIQUIDS & TEMPERATURES
These pumps are suitable for all liquids that are
compatible with bronze. Most common liquids are water, oil, and mild
chemicals in the pH range of 4 to 11. Viscous liquids require reduced
shaft speeds of 1150 RPM or lower. (Consult factory.) Liquids containing
solids, abrasives, powders, or paint pigments are definitely not
recommended for gear pumps. If abrasives are unavoidable, use a very low
shaft speed. See price book for the recommended liquid temperature
range of lip and mechanical seals. If more extreme temperature
conditions exist, factory should be consulted. Freezing of water-filled
pumps can cause damage and must be avoided. Oils at low temperatures are
very viscous requiring a lower speed or extra power.
SUCTION LIFT
As a general rule, the suction lift should be
kept at an absolute minimum by placing the pump as close to the liquid
source as possible. A gear pump in new condition can lift 20 feet of
water in the suction line. A foot valve (preferably with built-in
strainer) is recommended at the beginning of the suction line. For a
first startup, the pump should be primed to avoid dry running. Minimum
size of the suction pipe is the size of the pump inlet port. For longer
suction lines (over 3 feet) or for viscous liquids, the pipe should be
at least one size or two sizes larger than the pump inlet port. If the
discharge line contains any throttling devices such as a shut-off valve,
a spray nozzle or other restrictive device, it is necessary to have a
relief valve in the system, which returns the liquid to the suction side
or to the tank. The relief valve is also available as part of the pump
itself (R-model pumps). However, built-in relief valves are only good
for intermittent service. If used continuously, the pump will overheat. A
built-in relief valve is strictly a safety device against overpressure.
It will not work successfully as a pressure or flow control device. For
this purpose a separate relief valve in the pressure line must be used.
Unless otherwise specified, the pump motor unit is supplied by the
factory for shaft rotation counterclockwise from shaft end. Reversing
motor will reverse “in and “out” ports and also requires changing relief
valve location. The relief valve is always on the inlet side of this
pump series. The factory pressure setting is 50 PSIG. To increase
pressure, turn the relief valve adjusting screw in a clockwise
direction.
