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HCFC 22 VAPOR LINE PRESSURE DROP/VELOCITY PER 100 FT. OF LINE
40
30
20
30
25
20
15
12.5
10
9
8
7
6
5
4
3
2
1.5
1.0
.9
.8
.7
40
30
20
To use this chart, first find capacity (tons) on left side of chart. To find pipe size, proceed right to smallest pipe size. Pressure drop (vertical line) and
velocity (diagonal lines) can then be determined for the pipe size selected. For example, for 10 ton unit, select 1 3/8 in. O.D. line.
NOTE - Shaded area denotes unacceptable velocity range.
Example -- Vapor Line Pipe Sizing
Given: 7 1/2 ton heat pump with indoor coil lower than out
door coil. Application includes 82 linear feet of piping and 4
ells. There is a 20 foot vertical lift and 62 feet of horizontal
run. Refer to figure 15.
At 45°F Evaporating Temperature and 125°F Condensing Temperature
HCFC 22 VAPOR LINE PRESSURE DROP (lbs./100 Feet)
15
10 9 8 7
6
5
15
10 9 8 7
6
5
HCFC 22 VAPOR LINE PRESSURE DROP (lbs./100 Feet)
4
3
2
1.5
EXAMPLE: 10 TON UNIT
1 3/8 IN. O.D. LINE
3.3 PSI DROP PER 100 FEET
2400 FPM VELOCITY
4
3
2
1.5
FIGURE 14
Find: Select tube size from figure 14.
Solution: 1 1/8 inch O.D. line with 6 psi per 100 feet pres
sure drop and 2900 fpm velocity is selected. Now, calculate
pressure drop due to friction to determine if this is a good
selection.
Page 14
1.0 .9 .8 .7 .6
.5
.4
.3
1.0 .9 .8 .7 .6
.5
.4
.3
.2
30
25
20
15
12.5
10
9
8
7
6
5
4
3
2
1.5
1.0
.9
.8
.7
.2
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