-33-
Model W1867/W1868/W1869 (For Machines Mfd. Since 11/18)
SE
TU
P
Figure.49.
Totaling static pressure numbers.
Main Line
6" Rigid Duct (0.037) at 20'
........
0.740
Branch Line
4" Rigid Duct (0.075) at 10'
........
0.750
4" Flex Duct (0.28) at 5' ................
1.400
Elbows/Branches
6" 45˚ Y-Branch
........................
0.329
4" 45˚ Elbow................................
0.225
Additional Factors
Seasoned Filter
........................
1.000
Total Static Pressure Loss ................
4.444
Figure.48.
Additional factors affecting static
pressure.
Example:
A typical
Data.Sheet.
Performance.Curve
is illustrated in
Figure.50
. Find 4.4 on the Static Pressure
axis (the amount of total static pressure
loss calculated in
Figures.49–50
), then
refer to the closest value on the CFM axis—
approximately 1120 CFM.
The 1120 CFM for the static pressure loss
of the line connected to the router is well
above the 220 CFM requirement of that
machine.
— If the CFM for your static pressure loss is
above the requirement of the machine
connected to the end of that branch line,
then dust collection will most likely be
successful. Congratulations! You've just
designed your own dust system. Refer to
the
Accessories
section on
Page.37
to
start buying the components necessary to
make your system a reality.
— If the CFM for your static pressure loss is
below the requirement of the machine,
then that line will not effectively collect
the dust. You must then modify some
of the factors in that line to reduce the
static pressure loss. Some of the ways to
do this include 1) installing larger duct,
2) reducing amount of flexible duct used,
3) increasing machine dust port size, 4)
moving machine closer to dust collector
to eliminate duct length, and 5) reducing
90˚ elbows or replacing them with 45˚
elbows.
3.
Add the additional factors from the
following table to your list.
Additional.Factors
Static.Pressure
Seasoned (well used)
Dust Collection Filter
1"
Entry Loss at Large
Machine Hood
2"
4.
Total your list as shown in the example
below to come up with your overall static
pressure loss number for that line.
Note:
A
lways account for a seasoned filter,
so you don't end up with a system that only
works right when the filter is clean.
Note:
When calculating static pressure loss
to determine if multiple lines can be left
open at the same time, only include the
main line numbers once.
5.
Compare the total static pressure loss
for that line to the closest CFM given in
Figure.50
for your dust collector.
Figure.50.
CFM for static pressure loss of line
connected to a dust collector & router.
Performance Curve
2500
2250
2000
1750
1500
1250
1000
750
500
250
0
0.0
1.0
2.0
3.0
4.0
5.0
6.0
7.0
8.0
9.0
10.0 11.0 12.0 13.0
1354
CFM
STATIC PRESSURE (Inch/H2O)
Closest
CFM
(1120)
4.4 SP
Loss
Summary of Contents for W1867
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