Bryan Boilers Forced Draft Steam Boilers, Service Manual

Page: 18 / 37

STEP 5: CORRECT EQUIVALENT INPUT FOR
SYSTEM K-FACTOR
The capacities listed in Table 1.8.15C are based
on a system k-factor equal to 7.5. For any other
k-factor, the vent capacity must be adjusted. This
is accomplished by adjusting the equivalent input
for the system using a k-factor correction factor,
designated F
3
.
Refer to Table 1.8.15E for the equivalent input
correction factor which applies to the k-factor
calculated in Step 4. This factor is designated as
F
3
.
Multiply the equivalent input calculated in Step 2
times factor F
3
from Table 1.8.15E. This step will
yield a new equivalent input, I:
I = MBH x F
1
x F
2
x F
3
eq. 15E
Using this adjusted equivalent input, check the
stack diameter by following Steps 2 thru 3 again.
If the stack diameter remains the same, the sizing
is complete. If not, redo Steps 4 thru 5 etc. until
an acceptable result is achieved.
Table 1.8.15E: K-Factor Equivalent Input Correction Factor F
3
K- Factor F
3
K- Factor F
3
K- Factor F
3
K- Factor F
3
K- Factor F
3
1.00 0.37
1.50 0.45
2.00 0.52
2.50 0.58
3.00 0.63
3.50 0.68
4.00 0.73
4.50 0.77
5.00 0.82 5.50 0.86
6.00 0.89
6.50 0.93
7.00 0.97
7.50 1.00
8.00 1.03
8.50 1.06
9.00 1.10
9.50 1.13 10.00 1.15
10.50 1.18
11.00 1.21
11.50 1.24
12.00 1.26
12.50 1.29
13.00 1.32
13.50 1.34
14.00 1.37 14.50 1.39
15.00 1.41
15.50 1.44
16.00 1.46
16.50 1.48
17.0 1.51
17.50 1.53
18.00 1.55
18.50 1.57
19.00 1.59
19.50 1.61
20.00 1.63
20.50 1.65
21.00 1.67
21.50 1.69
22.00 1.71
22.50 1.73
23.00 1.75