STEP 2:
Determine the miles of pipe
9000 ft
= 1.70 mi
5,280 ft/mi
STEP 3:
Determine head loss
Hf = 28.8 ft/mi x 1.70 mi = 49 ft
STEP 4:
Determine head remaining
225 ft - 49 ft = 176 ft
PART D FRICTION LOSS
Friction Loss in Valves and Fittings: Friction losses in valves and
fittings result from the same surface friction losses in straight pipe. So
far we have only considered the losses in pipe. Now we are going to find
out how to compute the losses through valves and fittings. Valves and
fittings have been mathematically evaluated to determine the friction loss
and the information has been put in graph form. Special consideration must
be given to terminals and tank farms because of the numbers of valves and
fitting used. This friction loss must be carefully evaluated to ensure that
feeder pumps can meet the required pressure to feed the mainline pumps and
to transfer fuel from tank to tank within the terminal.
Now we can calculate the equivalent length for a pipeline that has a
certain number of valves and fittings. This number would then be added to
the pipeline length. For example:
3 rising stem gate valves
2 swing check valves
1 90 degree welding elbow
All valves and fittings are 8.415 inch diameter
Gate valve - 6.2 x 3 = 18.6
Swing check valve - 70.0 x 2 = 140
90 degree welding elbow 95.0 x 1 = 9.5
Total
= 168 ft
Given:
JP-5 at 80, F
Q = 700 GPM
d = 8.415 inches
Valves and fitting equivalent length = 188 Feet
Pipe length = 2.5 mi
Find:
Total head loss due to friction (Hf)
STEP 1:
Determine Hg
NOTE:
Using Figure 2-1, at 700 GPM and 8.415 inch pipe Hg = 34 ft/mi
STEP 2:
Determine correction factor using Table 2-1.
Correction factor = 1.17
STEP 3:
Determine True Gradient
12-24
QM 5099
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