Oberdorfer 700CP Bronze Centrifugal Pump End, 3.75" Impeller

Oberdorfer 700CP Bronze Centrifugal Pump End – 3.75" Impeller, Close-Coupled, No Motor

The Oberdorfer 700CP is a heavy-duty bronze centrifugal pump end designed for demanding fluid transfer and continuous circulation service across a wide range of industries. Built around a 3.75-inch bronze impeller paired with a 416 stainless steel shaft and a carbon/ceramic Nitrile mechanical seal, this pump end delivers flows up to 90 GPM at speeds reaching 3450 RPM. It mounts directly to any standard NEMA 56J C-flange jet pump motor with a weld-on base and threaded shaft end — making it an ideal drop-in pump head for new installations or replacement applications where the motor is already in place.

What sets the 700CP apart is its versatility across service environments that have nothing to do with the sea. It handles water, oils, mild solvents, water solutions, and a broad range of commercial chemicals, with temperature tolerance up to 212°F and pressure capability up to 75 PSI. Common uses include boiler feed, cooling tower circulation, condensate return, filtration systems, irrigation, spray systems, jockey pump service, chemical processing, and general liquid transfer. Because the impeller never contacts other pump components during operation, the unit runs quietly and efficiently — and since flow is non-positive, the discharge line can be shut off completely without the risk of overpressure or the need for a relief valve.

Key Features

• Close-coupled pump end only — no motor included; mounts to standard NEMA 56J C-flange jet pump motors
• 3.75-inch bronze impeller attached directly to the motor shaft for efficient, quiet centrifugal pumping action
• 416 stainless steel shaft for corrosion resistance and long service life
• Carbon/ceramic mechanical seal with Nitrile rubber element (standard); optional Viton (S10) or PTFE (S11) seals available for aggressive chemicals and elevated temperatures
• Flow can be controlled via a throttling valve on the discharge line — no relief valve required
• Capable of handling liquids with small impurities and viscosities up to 2,000 Saybolt Seconds Universal (SSU)
• Corrosion-resistant bronze construction compatible with water, water solutions, oils, mild solvents, and many commercial chemicals

Applications

• Boiler feed and condensate return systems
• Cooling tower and HVAC circulation
• Industrial filtration and chemical processing
• General water transfer, boosters, and irrigation
• Spray and wash-down systems
• Jockey pump service
• Fountain and water feature circulation
• Light chemical transfer in manufacturing and processing facilities

Specifications

• Part Number: 700CP
• Construction: Bronze
• Impeller: 3.75-inch Bronze, open vane
• Shaft: 416 Stainless Steel
• Mechanical Seal: Carbon/Ceramic – Nitrile (standard); Viton (S10) and PTFE (S11) optional
• Inlet Port: 1-1/4 inch NPT
• Outlet Port: 1 inch NPT
• Maximum Flow: 90 GPM
• Maximum Pressure: 75 PSI
• Maximum Temperature: 212°F
• Required Motor: 3/4 HP, 3450 RPM, NEMA 56J C-flange (not included)
• Motor Mount Type: NEMA 56J Flange, weld-on base, threaded shaft end
• Rotation: Counter-clockwise (viewed from inlet end)
• Priming: Not self-priming; flooded suction required or foot valve with manual prime; suction lift up to 15 feet with foot valve

Frequently Asked Questions

Q: Does the Oberdorfer 700CP come with a motor?
No. The 700CP is a pump end only. It is designed to mount to a separately purchased NEMA 56J C-flange jet pump motor rated at 3/4 HP and 3450 RPM. If you need a complete pump-and-motor unit, Oberdorfer offers several 700CP-M series combinations.

Q: Can the 700CP handle chemicals other than water?
Yes. The bronze construction and standard Nitrile mechanical seal make it compatible with water, water solutions, oils, and many mild solvents and commercial chemicals. For more aggressive solvents, acids, or elevated temperature service, the optional Viton (S10) or PTFE (S11) seal upgrades are recommended — contact Oberdorfer or your distributor for chemical compatibility guidance specific to your application.

Q: Is this pump self-priming?
No. Like all Oberdorfer 700 series centrifugal pumps, the 700CP requires flooded suction — the pump must be installed below the liquid level so fluid flows to it by gravity. If that is not possible, a foot valve installed at the beginning of the suction line combined with manual priming of all air from the pump will allow suction lifts of up to 15 feet.

Q: What happens if the discharge line is closed while the pump is running?
Because the 700CP produces non-positive flow, closing the discharge completely will not overload the motor or burst the line. No pressure relief valve is required. Horsepower demand decreases as pressure increases, with maximum power draw occurring at full open discharge.

Q: Can the 700CP handle liquids with solids or abrasives in them?
It can handle liquids that contain small impurities or minor solid content, but any abrasive content will accelerate mechanical seal wear and reduce seal service life. For applications with consistent solid or abrasive content, consult Oberdorfer directly to evaluate whether a different pump configuration is better suited.