/ 3.6 \ w^{2} L
p = 0.04839 K | 1 + ----- | ----------- (43)
\ d_{1} / D d_{1}^{5}
Some of the experimental determinations for the value of K are:
K = .005 for water (Unwin).
K = .005 for air (Arson).
K = .0028 for air (St. Gothard tunnel experiments).
K = .0026 for steam (Carpenter at Oriskany).
K = .0027 for steam (G. H. Babcock).
The value .0027 is apparently the most nearly correct, and substituting
in formula (43) gives,
/ 3.6 \ w^{2} L
p = 0.000131 | 1 + ---- | ----------- (44)
\ d_{1}/ D d_{1}^{5}
/ pDd_{1}^{5} \
w = 87 | -------------- |^{½} (45)
| / 3.6 \ |
| | 1 + ---- | L |
\ \ d_{1}/ /
Where w = the weight of steam passing in pounds per minute,
p = the difference in pressure between the two ends of the pipe in
pounds per square inch,
D = density of steam or weight per cubic foot,[80]
d_{1} = internal diameter of pipe in inches,
L = length of pipe in feet.