Oberdorfer 170M-A81 Bronze Centrifugal Pump — 12V DC, 3/4" NPT Ports, 20 GPM
The Oberdorfer 170M-A81 is a well-built, compact bronze centrifugal pump designed for reliable fluid movement in a wide range of 12-volt DC applications. Running at 3,480 RPM and powered by a 1/10 horsepower TEFC (Totally Enclosed Fan Cooled) motor, it delivers flow rates up to 20 GPM through 3/4-inch NPT inlet and outlet ports. The pump body is constructed from rugged, corrosion-resistant bronze, and the motor shaft is made from 316 stainless steel — materials chosen to hold up in demanding environments where moisture, chemical exposure, or continuous duty cycles are common.
What sets this pump apart is its thoughtful engineering in a small package. The single open-vane rotating impeller works without contacting other pump parts, which means quieter, more efficient operation and less wear over time. A Buna (nitrile) lip seal with stainless steel spring reinforcement provides reliable, low-maintenance sealing. Because the flow is not positive-displacement, you can fully shut off the discharge line without risking motor overload or line damage — no relief valve needed. This flexibility, combined with its low voltage DC operation and corrosion-resistant construction, makes the 170M-A81 a practical choice for cooling loops, heat exchanger circulation, fluid transfer, and other low-pressure pumping duties.
Key Features
- 12V DC TEFC (Totally Enclosed Fan Cooled) motor for reliable continuous-duty performance
- Corrosion-resistant bronze pump body and impeller construction
- 316 stainless steel motor shaft for long-term durability
- Single open-vane rotating impeller — no metal-to-metal contact for quiet, efficient operation
- Buna (nitrile) lip seal with stainless steel spring reinforcement
- 3/4" NPT inlet and 3/4" NPT outlet ports
- No relief valve required — discharge line can be fully closed safely
- Flow easily controlled with a throttling valve on the discharge side
- Compact and lightweight design
Applications
- Coolant and heat exchanger circulation systems
- Engine block temperature control and radiator loops
- Industrial fluid transfer and low-pressure circulation
- Hydraulic cooling and fluid conditioning systems
- Agricultural and irrigation fluid transfer
- HVAC and chiller water circulation
- Windshield/windscreen washing systems
- Livewell, baitwell, and aquaculture water circulation
- General-purpose DC-powered liquid transfer
Specifications
- Part Number: 170M-A81
- Voltage: 12V DC
- Motor Type: TEFC (Totally Enclosed Fan Cooled), Single Phase
- Horsepower: 1/10 HP
- Speed: 3,480–3,700 RPM
- Flow Rate: Up to 20 GPM
- Inlet Port: 3/4" NPT
- Outlet Port: 3/4" NPT
- Pump Body Material: Bronze
- Impeller Material: Bronze
- Shaft Material: 316 Stainless Steel
- Seal Type: Buna (Nitrile) Lip Seal with Stainless Steel Spring
- Maximum System Pressure: 15 PSI (recommended maximum)
- Motor Enclosure: TEFC
Frequently Asked Questions
Q: What types of fluids can the Oberdorfer 170M-A81 handle?
The 170M-A81 is suitable for water, water-glycol coolant mixtures, and other low-viscosity, non-aggressive fluids compatible with bronze, stainless steel, and Buna nitrile seals. It is not recommended for fuel, strong acids, or fluids that attack bronze alloys.
Q: Does this pump require priming before operation?
Yes, as a centrifugal pump, the 170M-A81 is not self-priming. It should be installed below the fluid source or otherwise positioned so that it starts with fluid already present at the inlet.
Q: Can the discharge line be closed while the pump is running?
Yes. Because the 170M-A81 uses a non-positive-displacement centrifugal design, the discharge line can be fully shut off without risk of overloading the motor or bursting lines. A relief valve is not required.
Q: What is the maximum recommended operating pressure?
The manufacturer recommends keeping system pressure at or below 15 PSI. Pressures above this level may force the lip seal out of the pump housing.
Q: Can this pump run dry?
No. Running the pump dry will damage the seal and impeller. Always ensure the pump is primed and fluid is flowing before sustained operation.
Q: Is the 170M-A81 compatible with a 24V DC system?
No. The 170M-A81 is rated specifically for 12V DC. For 24V DC applications, Oberdorfer offers the 170M-A82, which is otherwise identical in physical configuration.
Q: How is flow rate controlled with this pump?
Flow can be conveniently regulated using a throttling valve on the discharge side of the pump. Horsepower demand decreases as back-pressure increases, so throttling is both safe and efficient with this design.
Q: What seal type does the 170M-A81 use, and how is it maintained?
The pump uses a Buna (nitrile) lip seal with stainless steel spring reinforcement, friction-pressed into a machined housing counterbore. Under normal operating conditions within recommended pressure limits, the seal requires no routine maintenance.
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