Chemsteel® Sealed Rotary Gear Pumps
Installation, Operation and Maintenance Instructions
Congratulations for choosing an Oberdorfer Chemsteel® pump,
the Industry Standard for quality since 1890.
Chemsteel® metal pump housings are made of top quality investment cast 316 Stainless Steel or Alloy C. Non-metallic pump
housings are constructed from injection molded Ryton® PPS or
PEEK®. Shafts are Stainless Steel, or Alloy B. Pumps are available with carbon-graphite bearings or with Teflon® bearings. No
bearing lubrication is required. Dynamic seal arrangements
include packing, lip, or mechanical seals for a variety of application requirements. Static cover o-ring seals eliminate gasket problems.
Application Range
Chemsteel® Rotary Gear pumps are of the external gear positive
displacement type, displacing a finite volume of fluid with each
shaft revolution. As such, capacity varies in direct proportion to
pump speed. They are suited to handle clear lubricating and nonlubricating fluids at temperatures to 450F. These pumps handle
viscous fluids to 100,000 cps (462,000 SSU) at reduced shaft
speeds, with flow rates to 60 GPM ( 227 LPM), differential pressures to 150 psig (10.3 BAR), and suction lift capability to 20 feet
(6.1 meters) for new pumps.
These instructions should be kept in a convenient location for
ready reference. The manual should be read carefully by persons
responsible for installation, operation, and maintenance of the
equipment. For ease of reference, a copy of the order should be
kept with the manual. Write down the pump model number as
shown on the pump nametag, and the date the unit was placed into
Site Preparation
Choose a site that allows easy access to the pump for maintenance. Consider protection from the elements. Guard against
drips and spray from nearby equipment. Choose a solid foundation for mounting. If noise is a concern, consider a rubber pad
under the pump base to dampen.
Flow Direction
Chemsteel® pumps will perform equally well in either direction.
To change flow direction effectively reversing the suction and
discharge ports, simply switch driver rotation by following motor
wiring diagram instructions. Most pump motor units are factory
supplied with clockwise shaft rotation (when viewing the pump
from the shaft end).
Field Inspection
Chemsteel® Rotary Gear pumps may be readily inspected in the
field usually without removal from the drive or system plumbing.
Simply remove the cover nuts (or cap screws) to pull the rear
cover. Before attempting an inspection, follow safety precautions
and be sure to read and understand this manual.
New Pump Receipt Inspection
Upon receipt, check for obvious shipping damage and completeness to purchase order requirements. Shortages or damage should
be reported immediately to the carrier and to your Oberdorfer distributor. Occasionally during shipment, possible misalignment or
other damage including cracked mechanical seal faces can occur.
As such, customers are advised to test the pump with water in a
convenient location prior to installing into the intended system.
If the pump is to be stored prior to installation, it is recommended that it be left in the original shipping carton with all shipping
plugs in place and stored in a dry environment avoiding temperature variations. Contact the motor manufacturer for specific motor
storage information.
Suction Plumbing
Suction side plumbing considerations are key to desirable pump
performance. Minimize head loss by assuring sufficient pipe size
(especially important for highly viscous services). Generally the
same size pipe as the pump ports is adequate. For long runs
(beyond 3 feet) or viscous fluids, use one or two pipe sizes larger. Strive to keep the lines as short and straight as possible. If flexible lines are used, they should be selected to prevent wall collapse. To keep the pump from being starved or running dry, be
sure there is sufficient fluid supply. A flooded suction is generally preferred. Suction lifts over 3 vertical feet and long horizontal
runs (beyond 3 lineal feet) require a foot or check valve below the
level of the liquid being pumped. When taking suction from a
tank or vessel, position the inlet above the maximum expected
level of solids. Use full-bore ball valves or gate valves to minimize restriction. Suction strainers should be properly sized to
minimize pressure drop and positioned for easy cleaning access.
If start-up screens are used, be sure they are removed prior to
placing the system into regular operation. Orient lines so as to
prevent formation of air pockets. Be sure all joints are tight. Flush
out all suction lines prior to installing the pump.
General Piping
For further ease of maintenance, use union fittings to connect the
pump to the system. Install a discharge priming tee for convenience. Do not spring the piping to connect the pump. Use piping
supports or hangers as required. When necessary, provide for
thermal expansion and contraction to avoid placing strain on the
pump. Be sure that connecting pipe male tapered threads are not
undersize. Properly sized pipe threads will tighten adequately and
(with proper thread sealant) will seal properly without risk of contacting the gears and interfering with pump performance. For
non-metallic pumps, plastic threads require finger tight connections & joint sealing compound such as Loctite® Pipe Sealant
with Teflon® or equivalent. Over tightening will cause cracks.
Proper alignment is key to all variations of seals and packing as
well as bearing performance. Improper alignment can lead to premature pump failure. Check the alignment carefully between the
pump and the drive.
Belt Drive
Ensure that the pump and motor shafts are parallel and in line. Be
sure that the belt tension is adequate (per the belt manufacturer's
recommendation) but do not overtighten. For heavy pulley loads,
external ball bearing supports should be incorporated. A single ½"
(A or 4L section) V-belt is satisfactory for drive speeds up to 1 HP
3450 RPM. For larger drive sizes, double-V belts are recommended. Install guards around all moving parts in accordance
with OSHA to prevent personal injury.
Pressure Relief
Discharge lines should be fitted with properly sized line pressure
relief valves to protect both the pump and the system. The relief
outlet should be piped back to the suction vessel. Relief valves
are available through your Oberdorfer representative.
Unless the pump has been shipped directly from the factory, it is
recommended to check all bolts and nuts for tightness to eliminate
possible leakage problems or destructive vibration. Chemsteel®
pump housing fasteners are factory installed to the following
torque specifications: (top of page)
Metal - Series R1
Bolt / Nut Head
10 mm hex
45 in-lbs
Metal - Series S2
Metal - Series S4
Metal - Series S9
10 mm hex
13 mm hex
13 mm hex
45 in-lbs
85 in-lbs
85 in-lbs
Non-Metallic - Series S2
Non-Metallic - Series S9
5 mm hex socket
6 mm hex socket
25 in-lbs
35 in-lbs
Flow By-Pass
When a flow by-pass system is used to control output from the
pump, the bypassed fluid should be directed back to the suction
vessel to avoid recirculation heat build-up. In cases where this is
not possible, connect to the suction at least 10 pipe diameters
length away from the pump inlet. Provisions for cooling should
be made in the event of recirculation heat build-up.
Pump Driver Mounting
Adapter kits (including faceplate, bracket, coupling components,
and hardware) are available for the full line of Chemsteel® Gear
pumps allowing Close Coupled connectivity to NEMA and IEC
motor frames. Assembly instructions are included with each kit.
Base mount kits (including baseplate, coupling components, coupling guard, and hardware) are also available for all Chemsteel®
Gear pumps. Contact your Oberdorfer representative for additional information.
Packing: For proper operation, the packing area must be cooled
and lubricated. Where packing lubricant is required, use it.
Recommended lubricants include:
High Temperatures
Soap-free grease
Fluorocarbon grease
Typical Source
Keystone 5P9
Halocarbon 25/20M
Dow Corning 41
Where pump is equipped with lantern ring and recirculating flush,
check for proper piping from pump discharge to lantern ring nipple. Where thorough flush of lantern ring packing area is intended, check flush stream piping.
Follow National Electrical Code.
Verify that electrical service is properly grounded,
fused, and adequately sized for motor
nameplate requirements. Check to be sure that
motor wiring connections are correct referring
to the wiring diagram on the motor nameplate
or inside the terminal box.
Lip: Pumps supplied with two lip seals and flush chamber
arrangement come factory supplied with a small amount of lubricant applied to the outer lip seal. The design is intended to be used
with an eternally supplied flush fluid. Remove the pipe plugs and
install "in" and "out" connections to the flush source. Failure to
supply flush fluid will lead to outer lip seal breakdown.
Mechanical Seals: (see above) Two types are offered as standard:
single internal (in both the wedge and bellows styles) and double
mechanical seals (in both the wedge and bellows styles). Both
require cooling and lubrication to perform properly. Do not run
pump dry. Ensure that the seal surfaces are wet prior to start-up
and operation. If a seal flush system is to be used, make sure the
system is connected to the cover ports correctly. Keep abrasives
out of the seal area. Dirty flush streams can destroy seal faces.
Dry running leads to immediate damage to pump components.
Due to tight running clearances, liquids containing
solids and abrasives will accelerate pump wear.
When possible, flush the pump after each usage.
Allowing liquid to freeze in the pump can cause damage.
If the pump's bearing areas or seal area runs hot, shut the pump
down and determine the cause. It is recommended that the line
mounted pressure relief setting should be 5 psig above the operating pressure in the discharge line. If start-up screens were used,
be sure they are removed prior to placing the system into regular
operation. Depending on suction conditions, it may be necessary
to reprime the pump for subsequent restarts.
Prior to start-up, recheck installation as described above. Verify
desired rotation by jogging the motor and make corrections if necessary. Before initial startup, pre-wet the gears and seal, make
sure the pump is adequately primed. Failure to do so could cause
immediate damage to pump components. Make sure that discharge valves are open.
Before attempting to service the pump: Disconnect motor power
and release all pressure within the system. Flush the pump thoroughly with a neutralizing fluid before attempting to disassemble.
Wear appropriate personal protection equipment and handle the
equipment with care.
Start pump and check for proper operation.
Packing Styles: Adjust packing as necessary, allowing adequate
time to run in. Do not overtighten the packing nut else damage to
the packing and the shaft can occur. A properly packed and adjusted packing nut will leak at about 10 drops every 3 to 5 minutes.
A packing nut runs hot, it is generally a sign that the packing is
too tight.
Lip Styles: No adjustment is necessary during operation. For two
lip arrangements, insure that flush fluid continues to be supplied
to the chamber.
Single Mechanical Seals: No seal adjustment is necessary. Check
mechanical seal flush arrangements where used.
Double Mechanical Seals: Pressurized flush must be in operation at an inlet pressure of 10 to 15 psi above intended pump discharge pressure prior to and when operating the pump. Flush must
continue when pump is stopped until pump pressure is reduced to
within 20 psi of double seal chamber pressure.
Since each installation differs, the frequency and extent of pump
maintenance is best established based upon past performance.
Keeping detailed maintenance records of past performance aids in
determining future preventative maintenance intervals. During
routine operating inspections, pay particular attention to seal and
bearing areas of the pump. Consult the motor manufacturer for
motor maintenance instructions.
Changing Applications
Verify that all wetted parts of the pump are compatible with the
new fluid to be handled and that the motor is adequately sized.
Check with your Oberdorfer distributor if in doubt.
Inspect for Wear
If your Chemsteel® Gear Pump exhibits reduced flow, an inability to maintain pressure, is noisy or performs otherwise abnormally, first refer to the Troubleshooting Matrix below. If the problem persists, the pump should be inspected for wear or damage.
Oberdorfer Chemsteel® Gear pump internals may be readily
inspected in the field usually without removal from the drive or
system plumbing. Simply remove the cover nuts (or cap screws)
to pull the rear cover. Full pump removal and complete disassembly 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 chemical deterioration.
Mechanical Seals
Pumps equipped with mechanical seals are of the standard pusher 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
No liquid
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
1) Pump shaft speed incorrect
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
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
Low liquid 2) Discharge pressure too high
3) Air leak at suction
1) Closed valves
2) Plugged suction
3) Air leak at suction
4) Suction lift too high
5) Motor wired incorrectly
6) Wrong rotation
1) Cavitating
2) Solid particles in fluid
3) Air or gas in fluid
4) Worn or damaged pump
1) Discharge pressure too high
2) Shaft speed too fast
3) Fluid viscosity higher than
Motor runs
4) Incorrectly wired motor
or overloads 5) Binding internal pump parts
6) Motors normally feel hot
1) Dry running
2) Solids in fluid
Seal leaks 3) Damaged during field
4) Seal material incompatible with
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
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
1) Open valves. Prime pump
2) Add suction strainer
3) Inspect and replace damaged components
4) Verify original application conditions. Consult factory
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.
5990 Firestone Drive
Syracuse, NY 13206
Phone (315) 437-0361 Facsimile (315) 463-9561
Toll-Free 1-800-448-1668
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 minimum 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 contaminated 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, pressing out the old seals, pressing in new replacement seals, while reinstalling retaining rings.
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 product 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.
For a period of 12 months from date of shipment, Oberdorfer
Pumps, Inc. warrants all of their pumps to be free from defects in material 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 manufactured by Oberdorfer Pumps, Inc are warranted only to the extent of
the original manufacturer’s warranty.
Oberdorfer Pumps, Inc assumes no responsibility for consequential 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.
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