FSL High Viscosity Filtration Systems

A dedicated contamination solution for bulk oil handling and fluid transfer. Designed to excel in filtering particulate from heavily contaminated oil, the FSL keeps gearbox lubricant clean and equipment running efficiently. Ideal for high viscosity gearbox or lube applications and highly contaminated fuel applications


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50” (127 cm)


22” (56 cm)


28” (71 cm)


222 lbs (101 kg)

Dimensions are approximations taken from base model and will vary according to options chosen.

Inlet with 3-way valve

FSL05-FSL10: 1” FNPT

FSL20-FSL30: 1.5” FNPT


FSL05-FSL10: 1” FNPT

FSL20-FSL30: 1.25” FNPT

Operating Temperature

Fluid Temperature

30°F to 225°F

(0°C to 105°C)

Ambient Temperature

-4°F to 104°F

(-20C to 40C)

Materials of Construction


Carbon steel with industrial coating

Electric Motor

TEFC, 56-215 frame

0.5-3 hp, 1450-1750 RPM, see Appendix for amp ratings

motor starter

MSP (motor starter/protector) in an IP65, aluminum enclosure with short circuit and overload protection.


Cast iron, positive displacement gear pump with internal relief. Maximum pressure on pump inlet 15 psi (1 bar). Consult factory for higher pressures.

Pump bypass

Full bypass at 150 psi (10 bar)

10 GPM pump is rated for intermittent duty only at pressures above 100 psi. Continual operation with dual clogged filters resulting in operating pressures over 100 psi will reduce pump life  and/or cause premature pump failure.
Pneumatic Option Air Consumption

~40 cfm @ 80 psi

Air consumption values are estimated maximums and will vary with regulator setting.
Media Description


G8 Dualglass high performance media combined with water removal scrim. βx[C] ≥ 4000 (βx ≥ 200)


G8 Dualglass, our latest generation of DFE rated, high performance glass media for all hydraulic & lubrication fluids. βx[C] ≥ 4000 (βx ≥ 200)


Stainless steel wire mesh media βx[C] ≥ 2 (βx ≥ 2)


2-5000 cSt

When sized and installed appropriately. Contact factory for applications above 800 cSt for sizing requirements.
Replacement Elements
FSL replacement elements
Filter Sizing Guidelines

Filter assembly clean element ΔP after actual viscosity correction should not exceed 10% of filter assembly bypass setting. See filter assembly sizing guidelines & examples. For applications with extreme cold start condition contact Hy-Pro for sizing recommendations.

LF ΔP Factor

FSL kfactors
Fluid Compatibility

Petroleum and mineral based fluids, #2 diesel fuels (standard). For specified synthetics contact factory for compatibility with fluorocarbon seal option. For phosphate ester (P9) or skydrol fluid (S9) compatibility select fluid compatibility from special options.

Hazardous Environment Options

Select pneumatic powered unit (Power Option 00) or explosion proof NEC Article 501, Class 1, Division 1, Group C+D. Call for IEC, Atex or other requirements. If Explosion Proof option (X--) selected, no electrical cord or cord reel will be included.