Johnson & Starley 42-451-09, Инструкции по установке, пусконаладке и обслуживанию

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TABLE 4. RESISTANCE FACTORS FOR USE IN CALCULATING EQUIVALENT LENGTHS
a. This appendix provides a procedure for estimating whether a given flue design is likely to
ensure full clearance of combustion products.
b. The procedure is based on calculating the ‘equivalent height’ of the flue under considera-
tion, i.e. that height of the straight vertical circular flue pipe of specific size which will pro-
duce the same flow rate as the flue under consideration. The equivalent height is calculated
from the formula:
where:
H
e
is the height of the equivalent flue;
H
a
is the vertical height of the actual or proposed flue;
K
i
is the inlet resistance of the flue;
K
o
is the outlet resistance from the flue;
subscript e refers to the equivalent flue diameter;
subscript a refers to the actual or proposed flue diameter;
K
e
is the resistance per unit length of the equivalent flue;
Sum K is the resistance (other than the inlet and outlet resistance) of the actual or proposed flue.
NOTE: K and Sum K are obtained from Table 2. K
o
and K
i
are obtained from Table 5.
c. Table 2 gives resistance factors for common flue components for use in the formula. Table 5 contains the
appropriate inlet and outlet flue resistances. The flue is likely to be satisfactory if its equivalent height exceeds
1m.
COMPONENT INTERNAL SIZE RESISTANCE FACTOR
Flue Blocks
197mm x 67mm 0.85 per meter run
231mm x 65mm 0.65 per meter run
317mm x 63mm 0.35 per meter run
140mm x 102mm 0.60 per meter run
200mm x 75mm 0.60 per meter run
183mm x 90mm 0.45 per meter run
Pipe
100mm 0.78
125mm 0.25
150mm 0.12
Chimney
213mm x 213mm 0.02
90˚ Elbow
100mm Pipe 1.22 per fitting
125mm Pipe 0.50 per fitting
150mm Pipe 0.24 per fitting
45˚ Elbow
100mm Pipe 0.61 per fitting
125mm Pipe 0.25 per fitting
150mm Pipe 0.12 per fitting
197mm x 67mm 0.30 per fitting
231mm x 65mm 0.22 per fitting
317mm x 63mm 0.13 per fitting
Raking Block
Any 0.30 per block
Adaptor Block
Any 0.50 per block
Terminal
100mm Ridge 2.5
125mm Ridge 1.0
150mm Ridge 0.48
100mm GCI 0.6
125mm GCI 0.25
150mm GCI 0.12
H
e
= H
a
x
(K
i
+ K
o
)
e
(K
i
+ K
o
)
a
- K
e
H
a
+ Sum K