Detailed mechanical seal inspection and replacement instructions
are included in Oberdorfer's Chemsteel® Gear Pump Inspection
and Repair Manual.
Lip Seals
Pumps equipped with lip seals are of the metal cased, teflon
backed, single viton lip style. These are intended to provide min-
imum friction drag with positive sealing and again should be
maintenance free provided the same conditions for mechanical
seals are met as well as:
6) Avoid scouring of the shaft in the lip seal area due to contami-
nated abrasives
7) Avoid excessive seal lip contact pressure on the pump shaft due
to excessive pump pressure.
These are readily replaceable by removing retaining rings, press-
ing out the old seals, pressing in new replacement seals, while re-
installing retaining rings.
Packing
Pumps equipped with Teflon®, Grafoil®, or Teflon® with
graphite packing require periodic adjustment as described above
in the Startup section to avoid excessive leakage. Eventually all
the packing in the pump will become deteriorated and will have
to be replaced.
Recommended Spares
Repair kits are available for all Oberdorfer Chemsteel® Gear
Pumps. For the proper kit, simply add a "K" to your pump prod-
uct number when contacting your Oberdorfer Distributor or the
factory. Kits are supplied with a full set of
internal components including gears, shafts,
keys, seals, and bearings.
system plumbing. Simply remove the cover nuts (or cap screws)
to pull the rear cover. Full pump removal and complete disassem-
bly may be needed for a comprehensive inspection. Refer to
Oberdorfer's Chemsteel® Gear Pump Inspection and Repair
Manual for detailed inspection and repair instructions covering a
range of service life conditions including opened clearances,
bearing wear, gear wear, bulged covers, scoured shafts, and chem-
ical deterioration.
Mechanical Seals
Pumps equipped with mechanical seals are of the standard push-
er bellows type or wedge style. They can be expected to provide
long and troublefree service provided:
1) Seal materials are compatible with pumped fluid and properly
applied to the service.
2) Adequate cooling and lubrication is provided
3) Dry running is avoided
4) Abrasives are kept away from the seal area
5) Pump and driver are properly aligned
DIFFICULTY
PROBABLE CAUSE
REMEDY
No liquid
delivery
1) Closed valves
2) Plugged suction
3) Air leak at suction
4) Suction lift too high
5) Motor wired incorrectly
6) Wrong rotation
1) Open valves
2) Eliminate restriction
3) Locate and repair leak
4) Do not exceed vapor pressure of liquid
5) Check wiring diagram
6) Correct rotation
Low liquid
delivery
1) Pump shaft speed incorrect
2) Discharge pressure too high
3) Air leak at suction
4) Worn or damaged pump
5) Low viscosity
1) Check driver speed, motor wiring, pulley tension
2) Reduce downstream pressure
3) Locate and repair leak
4) Inspect and repair as required
5) Verify original application conditions
Gradually
loses
prime
1) Suction lift too high
2) Air or gas in fluid
3) Air leak at suction
4) Worn or damaged pump
1) Improve suction pressure
2) Eliminate air or gas from fluid
3) Locate and repair leak
4) Inspect and repair as required
Noisy
1) Cavitating
2) Solid particles in fluid
3) Air or gas in fluid
4) Worn or damaged pump
1) Improve system suction pressure, provide adequate NPSH
2) Install suction strainer. Clean suction strainer
3) Eliminate air or gas from fluid
4) Inspect and repair as required
Motor runs
hot
or overloads
1) Discharge pressure too high
2) Shaft speed too fast
3) Fluid viscosity higher than
expected
4) Incorrectly wired motor
5) Binding internal pump parts
6) Motors normally feel hot
1) Reduce downstream pressure. Check relief valve setting. Be
sure discharge pressure gages functions correctly
2) Reduce speed
3) Change to larger horsepower or higher service factor motor.
Thin fluid.
4) Check wiring diagram
5) Inspect and corr
Seal leaks
1) Dry running
2) Solids in fluid
3) Damaged during field
replacement
4) Seal material incompatible with
fluid
1) Open valves. Prime pump
2) Add suction strainer
3) Inspect and replace damaged components
4) Verify original application conditions. Consult factory
TROUBLE SHOOTING MATRIX
5990 Firestone Drive
Syracuse, NY 13206
Phone (315) 437-0361 Facsimile (315) 463-9561
Toll-Free 1-800-448-1668 www.oberdorfer-pumps.com
Teflon® is a regsitered trademark of DuPont, an equivalent fluoropolymer may be used.
Ryton® is a registered trademark of Chevron Phillips Chemical, an equivalent polyphenylenesulfide may be used.
PEEK® is a registered trademark of Victrex, an equivalent polyetheretherketone may be used.
Grafoil® is a trademark of UCAR Carbon Technology, an equivalent may be used.
Loctite® is a trademark of Henkel Company.
CH-IOM 11
4
OBERDORFER PUMPS LIMITED WARRANTY
For a period of 12 months from date of shipment, Oberdorfer
Pumps, Inc. warrants all of their pumps to be free from defects in mate-
rial and workmanship when used in a service for which the product was
designed. If any pump or part is proved to be defective in workmanship
or material on examination in our factory, and is forwarded to our factory
by prepaid carrier, it will be repaired or replaced (at the factory’s option)
and returned to the customer f.o.b. destination.
Oberdorfer Pumps, Inc. assumes no liability for pumps that
have been altered or tampered with in any way. No pump shall be
returned to the factory for warranty service or credit without prior
arrangement with the factory and the assignment of a return goods
authorization number.
This warranty is not to be construed that our product shall be
deemed fit or suited for all or any particular service. Our pumps are not
designed or intended for use with every known substance. If you require
assurance or satisfactory pump service life, you are urged to discuss
your proposed usage with the company.
Equipment and accessories (motors, controls, etc.) not man-
ufactured by Oberdorfer Pumps, Inc are warranted only to the extent of
the original manufacturer’s warranty.
Oberdorfer Pumps, Inc assumes no responsibility for conse-
quential damages arising from the operating failure of the equipment for
any reason whatsoever. The company will assume no liability for service
calls or expenses incurred in the installation or removal of defective
equipment and replacements.
