Oberdorfer 700B Bronze Centrifugal Pump End – Reliable High-Flow Performance with a 3.5" Impeller
The Oberdorfer 700B is a rugged, close-coupled bronze centrifugal pump end built to handle demanding fluid transfer tasks across a broad range of industrial, agricultural, commercial, and light-duty processing environments. Designed to mount directly to a standard NEMA 56J flange jet pump motor — with a weld-on base and threaded shaft end — this pump end accepts a single-phase, 1/2 HP motor running at 3,450 RPM, making it a practical and versatile replacement or new-installation choice wherever reliable high-flow pumping is needed. The entire pump housing and 3.5-inch impeller are constructed from bronze, while the shaft is 416 stainless steel, giving the unit strong resistance to corrosion in water, oils, and mild solvent applications up to 212°F.
What sets the 700B apart in everyday use is the simplicity of its centrifugal design. Liquid enters at the center of the impeller and is thrown outward by centrifugal force — with the impeller making no contact with other pump components — delivering quiet, efficient operation with flows reaching up to 70 GPM and a maximum pressure of 19 PSI. There is no relief valve required, and flow can be conveniently managed with a throttling valve on the discharge side. The pump is not self-priming; it performs best in flooded-suction installations, though with a properly installed foot valve and manual priming, it can handle up to 15 feet of suction lift. The Buna mechanical seal (Carbon/Ceramic) keeps the unit tight and long-lasting under normal operating conditions, with optional Viton or PTFE seals available for more aggressive chemical environments.
Key Features
- Bronze construction throughout housing and impeller for excellent corrosion resistance
- 3.5-inch bronze impeller for high-flow output up to 70 GPM
- 416 stainless steel shaft for durability and strength
- Carbon/Ceramic mechanical seal with Buna (Nitrile) rubber element — standard
- Optional Viton (fluoroelastomer) and PTFE seals for solvents, chemicals, and elevated temperatures
- Close-coupled design mounts directly to NEMA 56J flange jet pump motors
- O-ring housing seal eliminates traditional gasket issues
- Discharge port orientation is adjustable to 8 positions for flexible installation
- Quiet, non-contact impeller operation — no relief valve required
- Handles liquids with small impurities without damage
Applications
- Water transfer and circulation in commercial and industrial facilities
- Agricultural irrigation and water supply systems
- Light chemical and solvent transfer (within compatibility limits)
- Oil transfer and lubrication fluid handling
- HVAC and building services fluid circulation
- General-purpose fluid handling in processing plants and manufacturing
- Replacement pump end for existing NEMA 56J motor installations
Specifications
- Part Number: 700B
- Pump Type: Close-coupled centrifugal pump end (no motor included)
- Construction: Bronze
- Impeller Diameter: 3.5 inches (bronze)
- Shaft Material: 416 stainless steel
- Seal Type: Mechanical — Carbon/Ceramic with Buna (Nitrile) element (standard)
- Optional Seals: Viton/fluoroelastomer (S10), PTFE (S11)
- Maximum Flow: 70 GPM
- Maximum Pressure: 19 PSI
- Maximum Temperature: 212°F
- Motor Requirement: 1/2 HP, 3,450 RPM, single phase, NEMA 56J flange (not included)
- Inlet Port Size: 1-1/4 inch NPT
- Discharge Port Size: 1 inch NPT
- Discharge Port Positions: 8 adjustable orientations
- Suction Lift (with foot valve and priming): Up to 15 feet
- Motor Frame Compatibility: Standard NEMA 56J with weld-on base and threaded shaft
- Phase: Single phase (1 phase)
- Motor Rotation: Counter-clockwise when viewed from inlet end
Frequently Asked Questions
Q: Does the Oberdorfer 700B come with a motor included?
No. The 700B is a pump end only. It is designed to close-couple to a separately purchased standard NEMA 56J flange jet pump motor with a weld-on base and a threaded shaft end. A 1/2 HP, 3,450 RPM, single-phase motor is required.
Q: Can the 700B handle chemicals or solvents other than water?
Yes, within limits. The standard unit is rated for water, oils, and mild solvents up to 212°F. For more aggressive chemicals, elevated temperatures, or severe solvents, optional Viton (fluoroelastomer) or PTFE mechanical seals are available.
Q: Is the Oberdorfer 700B self-priming?
No. This pump is not self-priming and requires a flooded suction installation — meaning the pump must be positioned below the liquid source so fluid flows to it by gravity. However, when a foot valve is installed at the start of the suction line and all air is manually bled from the pump, it can achieve suction lift of up to 15 feet.
Q: In how many positions can the discharge port be oriented?
The discharge port on the 700B can be set in 8 different positions, giving installers significant flexibility to route the outlet line in the most practical direction for the application.
Q: Do I need a pressure relief valve with this pump?
No. Because the 700B is a centrifugal pump, the discharge line can be fully closed without risk of overloading the motor or bursting any lines. Flow control is safely managed with a throttling valve on the discharge side, and no relief valve is necessary.
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