The FRA Series electric fuel pump operates at a constant frequency — it will continue to cycle as long as electric power is supplied.
If there is no demand for fuel, the pump will build pressure in the fuel delivery line - up to its rated maximum pressure - and continue to cycle, but with no fuel output.
As such, it is not well-suited for continuous operation/low demand applications such as heater or stove systems, since it will constantly make noise, and have a shortened service life due to high cycling.
For stove/heater and continuous duty applications, use the Walbro FRD series of pumps, which addresses these issues. See Related Products, below.
An FRA pump can be used, however, to fill a gravity-feed day tank commonly used in diesel stove and heater installations.
FRA pumps incorporate a new piston mechanism which, unlike rubber diaphragms, is not affected by modern, high-tech fuel blends.
The FRA is designed to serve as a primary pump (replacing a mechanical fuel pump) or as an auxilliary fuel pump (assisting the existing pump) for internal combustion engines.
The pump self-regulates to its pre-set pressure, pumping more or less fuel as the delivery pressure (head) varies.
FRA pumps are commonly used as replacements for failed mechanical fuel pumps on older engines, where the owner doesn't want to continue using a pump with a rubber diaphragm susceptable to degradation by modern alcohol fuel blends.
They are also commonly used in open flow, low head applications such as fuel polishing.
• Non-adjustable maximum output pressure is factory pre-set in the ranges indicated below
• Output pressure can be further regulated by screwing in, or placing in-line, an adjustable pressure regulator such as the HOL 12-804
• FRA provides low cost with good durability
• Compatible with all commercially available pump grade gasoline, gasoline-alcohol blends, diesel, and bio-diesel fuels
• Continuous duty life (diesel fuel): >5,000 hours
• Flow rates as high as 52 gph, but 30 gph is a more typical maximum
• Current draw averages less than 2 amps
• Self-priming to at least 2 feet; maximum dry run time is 4 hours
• Inlet (bottom)/Outlet (top): 1/8-27 NPSF (Dryseal American National Standard Straight Pipe Thread) — will accept NPT tapered fittings without leaking, thread sealant recommended
• No internal filter - a 70 micron, or finer, pre-filter is recommended
• USCG 16623-1 and 16623-2 approved; ignition protected
• Dichromate coating passes 96 hour salt spray test - not recommended where exposed to saltwater
• Dimensions: 5.43"H x 2.76"Dia.
• Note - a suffix number (typically -1 or -2) in part number refers to type of packaging
• Made in USA
NOTE — The FRA Series of pumps is supplied with a kit of commonly used installation fittings: mounting fasteners, wire terminals, hose barbs and clamps. Although the included instructions reference (4) hose clamps, the clamps have been re-designed, and now only (2) are needed.
Heavy on the technical side...
Selecting among the Walbro FR Series electric fuel pumps:
• All the FR electric pumps provide fuel until the fuel demand decreases, or flow is restricted - but they have different mechanisms for doing so.
FR pumps will cycle (pump) until they build up the pressure (head) in the outflow line - with an accompanying decrease in fuel flow - and reach their factory preset maximum pressure.
At this point, constant frequency pumps like the FRA will continue cycling - but no fuel will flow.
Variable frequency pumps, like the FRB and FRD, will slow and eventually stop cycling as the pressure builds.
If the pressure on the outflow side of the pump drops, both types of pump will start supplying fuel again.
• Choosing an FR Series pump is often less dependent on the application, and more a matter of user preference:
— FRA pumps are lower cost, basic models.
They have no built-in filter, and their constant cycling means electric current draw is constant - regardless of output, they are always making noise, they typically have a shorter lifespan (higher wear), and they can wear unevenly as the stroke can be shortened when operating near their maximal pressure.
— FRB and FRD pumps have a more expensive variable frequency circuit board, always use their full stroke length - so wear is evenly distributed, do not always operate at full capacity/maximal cycling — so less wear, longer life, less noise, and lower average current draw.
Additionally, the FRB models include a built-in/replaceable 70 micron mesh filter, so the user doesn't need to supply a pre-filter.
• What the FR fuel pump is designed to do:
— In carbureted applications - The FRA and FRB fuel pumps self-regulate to their maximum output pressure when the carburetor bowl is full, and respond to float movement in the carburetor as required.
When the engine demands more fuel, the pump increases its flow rate.
When the engine demand drops, the pump reduces its flow rate.
— In diesel applications - The FRA and FRB pumps will deliver fuel to the diesel injector pump, assuring a positive pressure at the injector pump inlet.
These pumps are designed to refill diesel filters after service or replacement.
— In transfer applications, including fuel polishing, FRA and FRB pumps run continuously, as long as electrical power is supplied to the pump, and output back pressure is low.
— In diesel heater and stove applications, the task-specific FRD pumps will slow their cycling rate to deliver only the fuel required by the stove fuel metering valve ("carburetor").
FRD pumps can also fill day tanks in gravity feed installations.
• Complete list of approved fuels for FR pumps:
— Unleaded regular gasoline, premium gasoline, gasoline-alcohol blends, diesel fuel, bio-diesel, Stoddard solvent, E85.
The versatile FR pumps are capable of pumping fluids other than fuels - including water and oils, thus having potential uses in many diverse applications. Please consult with us first, however, if you have a non-listed application in mind for one of these pumps, as there may be technical issues to resolve.