Flanders PrecisionAire 425T Specifications

For use as a pre-filter
The 425T panels are manufactured from
two distinct 100% resin bonded polyester
media layers with a wire support frame
sealed between the two layers. This
provides a self-supportive, self-sealing
panel filter which significantly decreases
air bypass when installed in the entire fil-
ter track.
The first layer is a 1.5" polyester media
which uses 45 denier polyester fibers
with an open weave on the entry side, 15
denier fibers with slightly tighter weave in
the middle, and 6 denier fibers with an
even tighter weave on the downstream
side. This triple denier entry media com-
bination provides three stages of filtration against particulate. The downstream side of
the media is treated with a special non-migrating tackifier which significantly increases
the filter's efficiency. The second media layer is made from 6 denier polyester fibers
heavily needled to a dense 1/4" depth. This adds a final layer of defense against
small particulate.
The progressive density media structure is what makes the 325T panel so effective.
The particles are "funneled" out of the airstream. Large particles are captured on the
outer layer and finer particles are captured in the second and third layers.
425T panel filters are available as single panels with one single wire sup-
port covering the entire filter area, or link panels utilizing multiple wire sup-
port pieces inside a single piece of media. Both the single panels and the
link panels are available in custom sizes.
Fractional Efficiency vs. Particle Diameter
100
80
60
40
20
0
0
110
1
Particle Diameter (µm)
425T Panel
4-Ply Polyester Panel Filter
Test Type
Test Number
Flow Rate/Velocity
Test Aerosol:
DP ("H20)
Size
Size
Range (mm)
0.3-0.4
0.4-0.55
0.55-0.7
0.7-1.0
1.0-1.3
1.3-1.6
1.6-2.2
2.2-3.0
3.0-4.0
4.0-5.5
5.5-7.0
10
7.0-10.0
Fractional Efficiency
T033103B
1968 cfm
KCI Neutralized
0.489
24x24 panel
Initial
Fractional
Efficiency (%)
2.3
9.6
19.7
34.0
46.9
53.4
60.3
68.5
77.0
82.3
86.0
90.1