Gorman-Rupp O3H O Series Power Take-Off Self-Priming Pump

The Gorman-Rupp O3H is the 3 inch gear-reducer power take-off (PTO) pump in the O Series. It is a compact, lightweight self-priming centrifugal designed to mount in the unused space between the chassis frame cross members of refuelling and water transfer vehicles, delivering up to 400 GPM and 270 ft of head, and is used to unload fuel, supply fire trucks and water wagons and control dust at quarries.

Built for truck-mounted fluid transfer

The pump uses a single saddle mounting with offset drive shafts that can be mounted in one of four positions to ease shaft alignment. Quiet-running, durable helical alloy steel gears are fitted and the gear drive can be right- or left-hand rotation. Where PTO or auxiliary drive connections are not acceptable, the units can be adapted to be driven by a DC or hydraulic motor. The manufacturer says the efficient, economical design permits multiple units on one vehicle, and names aircraft fuels, fuel oil, gasoline and other petroleum derivatives as ideal liquids.

Technical specification

3 inch versus 2 inch

The 2 inch O2F reaches higher head (444 ft on petroleum, 355 ft on water at 173 GPM) but cannot pass solids, while the O3H trades head for flow and passes 0.44 inch solids. The straight-in suction design and absence of a check valve on 3 inch models eliminates entrance restrictions and gives better performance with clean fluids. A replaceable wear ring maintains efficiency over time.

Notes for installation

The pump has a heavy-duty mounting pedestal and an oil-lubricated gearbox; follow the manufacturer’s instructions for oil, rotation and PTO shaft alignment. The brochure states no approvals for fuel handling, so request the relevant certification if the vehicle will operate in a regulated fuel service.

Duty point in other units (derived)

Unit conversions below are calculated from the printed maximum values and are not manufacturer statements.

Mounting is on the vehicle frame, so provide the PTO shaft type, direction of rotation (the gear drive is available right- or left-hand) and the expected flow in the fill or transfer mode. Several units can be fitted on one vehicle where different liquids are carried. Since the pump has no suction check valve in the three inch size, an in-line valve or priming plan should be agreed for the hose arrangement.

Ordering information and support

Manuals, parts lists, curves and outline drawings for the O Series power take-off pumps are available in PDF and CAD form through the manufacturer, and parts are shipped quickly from stock according to the brochure. For quotation provide the vehicle chassis arrangement, drive shaft position (one of four), rotation hand, the liquid (water or petroleum) and whether a DC or hydraulic motor adaptation is needed instead of a PTO drive.

Since the same literature covers the 2 inch O2F, a buyer deciding between the two should compare solids passage and head together: the O2F gives the higher head but passes no solids, whereas the O3H passes 0.44 inch solids at lower head and higher flow. Ask the manufacturer for the rotation and gear ratio data that apply to your PTO speed, because the brochure gives only maximum duty values.

Related Gorman-Rupp products: Gorman-Rupp U4B Super U Series Self-Priming Pump, Gorman-Rupp V4A Ultra V Series Self-Priming Trash Pump, Gorman-Rupp SF4C SF Series Submersible Solids-Handling Pump, Gorman-Rupp 6508A 6500 Series Solids-Handling Pump, Gorman-Rupp VGH4D VGH Series High-Efficiency Centrifugal Pump and Gorman-Rupp PA6A Prime Aire Priming-Assisted Pump.

Documents and quotation

Brochure: O Series Power Take-Off (AV-05974). See Pumps. Seven Star LLC is an independent supplier in Muscat; send vehicle and rotation requirements for a quotation.