Oberdorfer 401H Pump 401M-2 with Manual Clutch — Bronze Pedestal Flexible Impeller Pump for Demanding Fluid Transfer Applications
The Oberdorfer 401H Pump, configured as the 401M-2 with a manual clutch, is a rugged, reliable bronze pedestal flexible impeller pump built for professionals who need dependable fluid transfer performance across a wide range of industrial, agricultural, and general-purpose applications. The pump end is constructed entirely of corrosion-resistant bronze paired with a high-chrome nickel stainless steel shaft, two sealed extra-capacity ball bearings with Teflon barrier seals, and a shaft slinger for added bearing protection — a combination that translates directly into a longer service life and fewer maintenance interruptions. The neoprene impeller is the standard fitment, with a Buna-N mechanical seal handling the primary sealing duties. The manual clutch configuration gives operators direct, hands-on control over pump engagement, making it especially practical in setups where independent on/off drive control is preferred without electrical clutch components in the loop.
What makes this pump particularly versatile is its self-priming capability. When the impeller is wet and the pump is fully primed, it can achieve suction lifts of up to 15 feet, making it adaptable to installations where the liquid source sits well below the pump. The flow rate reaches up to 36 GPM, and the pump accepts either a direct drive with a flexible coupling or a pulley drive arrangement, giving integrators flexibility in how they tie it into their existing power source. The 1-inch FNPT inlet and 1-inch FNPT discharge ports are straightforward to plumb, and the pump can be mounted in virtually any position without loss of performance. Whether it's handling water transfer in agricultural settings, fluid circulation in light industrial processes, or general-purpose liquid movement, the 401M-2 with manual clutch delivers consistent, dependable output that Oberdorfer has stood behind for well over a century of pump manufacturing.
Key Features
- All-bronze construction for maximum corrosion resistance and long-term durability
- High-chrome nickel stainless steel shaft (Grade 303) for added strength and corrosion protection
- Two sealed, extra-capacity ball bearings spaced for maximum load capacity
- Teflon barrier seals protecting ball bearings from contamination
- Shaft slinger providing supplementary bearing protection
- Buna-N mechanical carbon ring / ceramic face main pump seal as standard
- Neoprene flexible impeller standard; optional Buna-N (nitrile) impeller available (both spline drive)
- Manual clutch engagement for direct operator-controlled pump drive
- Self-priming design — suction lift up to 15 feet when impeller is wet and pump is fully primed
- Compatible with direct drive (flexible coupling) or pulley/belt drive configurations
- Can be mounted in any position without loss of performance
- Large vent and drain openings that keep the seal and bearing chambers separate
- Pump end only — no motor included
Applications
- Agricultural water and fluid transfer
- Industrial process fluid circulation
- General-purpose liquid transfer in light manufacturing environments
- Irrigation and irrigation support systems
- Engine-driven pump systems requiring manual clutch control
- Fluid recirculation in stationary or mobile industrial equipment
- Wash-down and water supply systems
- Chemical-adjacent transfer of compatible, non-severe liquids
Specifications
- Model / Part Number: 401H / 401M-2
- Drive Type: Manual clutch
- Construction: Bronze
- Shaft Material: High-chrome nickel stainless steel (Grade 303)
- Impeller Material: Neoprene (standard); Buna-N / Nitrile (optional)
- Seal Type: Buna-N mechanical seal (carbon ring / ceramic face)
- Inlet Port Size: 1 inch FNPT
- Discharge Port Size: 1 inch FNPT
- Maximum Flow Rate: 36 GPM
- Maximum Suction Lift (primed): 15 feet
- Operating Temperature Range (Neoprene impeller): 45°F to 180°F (7°C to 82°C)
- Bearing Type: Two sealed extra-capacity ball bearings
- Drive Options: Direct drive (flexible coupling) or pulley/belt drive
- Mount Type: Bronze pedestal
- Pump Configuration: Pump end only (no motor)
- Manufacturer: Oberdorfer Pumps (an Ingersoll Rand company), Syracuse, New York, USA
Frequently Asked Questions
Q: What is the difference between the 401H and the 401M-2 designations?
The 401H refers to the overall pump model series in Oberdorfer's lineup, while 401M-2 is the specific catalog part number identifying the bronze pedestal pump end configuration. When listed together as "401H Pump 401M-2," it identifies this particular pump end unit with its specific construction and seal options within the 401 series family.
Q: Does the manual clutch come pre-assembled with the 401M-2 pump end?
The 401M-2 is sold as a pump end only without a motor. The manual clutch is a drive engagement component that must be integrated into your drive system. Clutch kit components are available separately and are designed to work with the 401M pedestal pump configuration. Confirm the correct clutch kit for your specific setup before ordering.
Q: Can the Oberdorfer 401M-2 run dry for short periods during startup?
No. The neoprene impeller relies entirely on the liquid being pumped for lubrication. Running the pump dry — even briefly — causes rapid impeller degradation due to high rubbing friction generated without fluid lubrication. Always prime the pump before startup, and never operate it without liquid present.
Q: What types of fluids is the 401M-2 with neoprene impeller suitable for?
The neoprene impeller is well-suited for water, light agricultural fluids, and general-purpose compatible liquids within its temperature range. It is not appropriate for severe solvents, concentrated acids, or fluids outside the 45°F to 180°F operating window. For chemically aggressive fluids, the optional Buna-N (nitrile) impeller may be a better fit depending on chemical compatibility.
Q: How is the direction of flow determined on the Oberdorfer 401M-2?
The direction of shaft rotation determines which port acts as the inlet and which acts as the discharge. The pump will operate correctly in either rotation direction, but you must confirm your shaft rotation before plumbing the inlet and discharge lines. Reversing shaft rotation effectively reverses the flow direction through the pump.
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