Screen vs. Paper Fuel Filters for Small Engines
Screen and Paper Filter Media
Paper fuel filters use filter elements made of polymer resin (phenolic resin) treated cellulose. This filter paper is considered a nonwoven filter media. Polyester felt sheets are another type of nonwoven filter media used for inline fuel filters.
Screen fuel filters use fine mesh screen filter elements. This screen is made of woven monofilament plastic or metal wires.
Fuel Filtration for Demanding Outdoor Power Equipment ApplicationsAll ICE (internal combustion engine), Outdoor Power Equipment (OPE), and Powersports machines require fuel filters to protect sensitive fuel system components. Optimized fuel filtration plays a significant role in maintaining consistent machine performance and improved longevity for more demanding applications.
Commercial groundskeeping, off-road Powersports and commercial-grade portable power generation are typical of these sorts of applications. Manufacturers build these machines with robust materials for handling rougher conditions. Notably, these machine designs include easy access for regular maintenance to maximize their service life.
Small engine applications
Applications where fuel system maintenance is critical for reliable engine performance:
- Portable power generation, primarily commercial grade generators
- ATV, UTV and utility vehicle maintenance and maintenance services
- Outdoor power equipment such as zero-turn, stand-on mowers, and snow blowers
- Off-road fleet, Powersports, and commercial small engine maintenance and fleet maintenance operations (MROs)
Why is fuel filtration for these small engine applications so demanding?
- Safety and durability requirements
- Performance requires higher, reliable fuel flow even at full load
- Designs provide easy access for carefully managed maintenance
- Machinery and repair costs that encourage maximizing its working life
Maintenance and repair management, fuel systems and fuel filter requirements:
- Filters durable enough to have a practical filter life
- Efficient filters that provide effective particle capture
- Filters that create no engine performance issues under full load
- 10% ethanol compatibility plus a broad resistance to alcohol exposure
Protecting modern ICE engines means using fuel filters resistant to alcohol exposure from different ethanol-gasoline blends, including E85. This alcohol resistance should include resistance to methanol exposure from fuel additives.
Protecting expensive machinery also means maximizing its life. Practical economics requires reliable fuel system component protection and fuel filters that are:
- Made to industry standards
- Made with high-quality materials
- Made using recognized good manufacturing practices (GMP)
Screen vs. Paper Filter Media
Screen filter elements
- Stainless steel wire screen mesh
- Polyester plastic monofilament mesh
Nonwoven filter elements
- Felted polyester sheet
- Polymer resin-treated cellulose (paper)
Small plastic inline gasoline filters typically use nonwoven filter components made of polymer-treated cellulose (paper) or synthetics like polyester felt.
Pleated paper and felt nonwoven filter elements have higher working surface areas and greater mechanical strength within the filter element. Maximizing filter element surface area increases flow through the filter while reducing flow restriction and pressure drop. A larger surface area also captures small particles more efficiently over time without reducing the filter's flow rate much.
Screen vs Paper: Pros and Cons
Particle capture
Mesh captures particles on its surface, aka sieving
- Cleanable
- High flow rates
Paper and felt capture particles on the surface and within the filter media
- Lower flow rates
- Capture finer particles
- Not cleanable or refreshable
Cleanability
Screen filter media
- Surface capture filter elements can be flushed out of a filter using backflushing or backwashing
Paper and felt nonwoven filter media
- Nonwoven filter media cannot be usefully cleaned or refreshed
- Attempted cleaning by backflushing can damage nonwoven filter media
Size
Screen filters are physically smaller than paper or felt filters with comparable flow rates. This smaller size makes them useful where space requirements are critical.
What About Fuel Flow and Flow Rates?
Small internal combustion engines require higher flow rates to power commercial-grade machines. This higher performance requires adequate fuel flow rates provided by fuel pumps, not gravity feed.
Screen filter flow
- High flow rates
- More easily clogged by an accumulation of debris
Paper filter flow
- Lower flow rates than mesh filters
- Pleating and larger filter element sizes help to increase flow
Flow matters for maximum fuel pump life
Screen filters before fuel pumps offers protection without restricting flow. Restricted flow places stress on the pump, leading to a shorter working life.
Fuel system components susceptible to clogging and erosive wear need fine particle protection. Install fuel filters with nonwoven filter elements (paper or felt) downstream of the fuel pump but just upstream of the engine. The fuel pump can then push enough fuel through the finer filter to avoid fuel starvation.
Estimating fuel flow for small engines
Small engine manufacturer specifications may provide fuel consumption rates. Base fuel consumption estimates on engines running at full throttle and under load. Use these estimates for determining filter flow requirements.
Matching fuel flow to maximum demand ensures enough fuel is provided to the engine, preventing fuel starvation. Full throttle under load is when good engine performance is most important. If fuel consumption rates are unavailable, estimate small engine fuel consumption at between 0.4 and 0.6 pounds per hour per horsepower.
Horsepower x Fuel Consumption = Pounds of Fuel Per Hour
The following fuel weights per gallon are approximate because the weight of gasoline can vary slightly between brands and grades:
- Diesel 6.9 pounds per gallon
- E85 gasoline 6.6 pounds per gallon
- Gasoline (E0, E10 and E15) 6.2 pounds per gallon
The engine's fuel flow requirement is the pounds per hour divided by the weight of the fuel per gallon.
Pounds of Fuel Per Hour / Pounds Per Gallon = Fuel Flow Requirement
What is ANSI/OPEI, and Why Does It Matter?
What advantages do ANSI-compliant filters have over non-compliant filters? Certified testing to Outdoor Power Equipment performance requirements ensures parts have the quality and durability needed for real-world conditions.
ANSI/OPEI B71.10 certified, independent testing standards
- Durability, sturdiness, and safety
- Material compatibility with both gasoline and 10% (E10) ethanol-blended gasoline
No ethanol, according to the OPEI, is ideal for outdoor power equipment. However, pure non-ethanol gas (E0) is becoming increasingly expensive and challenging to get. It is reasonable to assume that Powersports and Outdoor Power Equipment will be exposed to E10 or other ethanol-gasoline blends.
How ITW OEM small engine filters go beyond ANSI performance standards
ITW fuel filters provide superior compatibility with E-85 ethanol-gasoline and good resistance to methanol exposure from fuel additives.
Superior design
- Overmolded filter element designs that eliminate the use of adhesives
Superior materials
PETg filter bodies instead of just PET
- More robust, more impact and heat resistant
- Higher chemical resistance, especially to alcohols
Find out more about the materials it takes to make reliable, sturdy plastic fuel filters >>
Impact and heat modified engineering grade nylon instead of commodity nylon filter bodies
- More robust, more impact and heat resistant
- Higher chemical resistance, especially to alcohols
304 stainless steel instead of brass or lower-grade steels
- Higher chemical resistance, especially to alcohols
Find out more about our compact and miniature inline filtration products >>
The Best Small Engine Fuel Filter Option?
Installing a screen filter upstream of the fuel pump with a nonwoven paper or felt filter downstream provides optimum fuel system protection and performance.
Large micron ratings capture coarse particles
Protect fuel pumps from damage by capturing coarse particles. Because mesh filters are high-flow filters, they should be installed upstream of a fuel pump. In general, use mesh screen filters with micron ratings between 75 and 150 microns for pre-pump filters.
Small micron ratings capture fine particles
Fuel filters with low micron ratings capture smaller particles. They protect sensitive fuel system component damage caused by fine particle erosion and clogging. These finer filters generally use nonwoven filter elements like polyester felt sheets and polymer resin-treated cellulose (paper).
Filter elements made of these types of materials are usually pleated. Also, the filters themselves tend to be physically larger than mesh screen fuel filters. The larger size and pleating increase the filter's effective surface area, which maximizes flow.
Filters with nonwoven filter components have micron ratings ranging from 10 microns or lower to as high as 80 microns. Install these filters downstream of fuel pumps and near the engine to protect fuel system components from fine particle damage.
Conclusion
Fuel pumps are necessary for demanding small engine applications with higher fuel flow rates. Install fuel filters with paper or felt filter elements downstream of fuel pumps and close to the engine.
Place screen filters with about 100-micron ratings and adequate flow rates just upstream of the pump. Manufacturer recommendations for placement and filter micron ratings should always override these rules-of-thumb. Also, use fuel filters with high enough flow rates that engines always perform well under full load. It is necessary whether the machine uses a gravity-fed flow or a fuel pump.
Use fuel filters and valves tested to and compliant with ANSI/OPEI B71.10 performance testing standards.
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- ANSI/OPEI B71.10 Compliant Fuel Valves and Filters >>
The ANSI/OPEI B71.10-2018 standard went into effect 12-Nov-2020. Learn more about ANSI-compliant plastic fuel filters and fuel shut-off valves. Find out how independent, third-party testing in certified labs confirms material and manufacturing quality by exposing critical fuel system components to stresses that mimic real-world operating conditions.
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