|
| |
2-7 General - Cont'd.
the intake line to the switching manifold. Differences in lengths will cause a variation in the pressure drop from the intake
to the end point. The available intake pressure may deviate downward from 150 psig. The information in this section is
intended as a guide to assist the responsible parties to make a proper judgment as to the effect on pressure drop and
flow rates of the potential deviations outlined above.
2-7.1 Elevation Head
If the elevation at the inlet is greater than the elevation at the end point, there will be additional pressure available due to
the elevation head. There will be less pressure available if the end point is higher than the inlet. At 60F. the pressure
in psi for each foot of elevation difference is as follows:
On Diesel (.85 Specific Gravity)
-
.369 psi per foot
On Jet Fuel JP-4 (.78 Specific Gravity)
-
.338 psi per foot
On MoGas (.72 Specific Gravity)
-
.312 psi per foot
The following table will permit quick estimating of the pressure effect of elevation differences.
Table 2-1
PRESSURE EFFECT OF ELEVATION DIFFERENTIALS
PRESSURE DIFFERENTIALS PSI
Required Pressure
Elev. Diff.
Diesel
JP-4
MoGas
Feet
5
1.9
1.7
1.6
10
3.7
3.4
3.1
15
5.5
5.1
4.7
20
7.4
6.8
6.2
25
9.2
8.5
7.8
30
11.1
10.1
9.4
35
12.9
11.8
10.9
40
14.8
13.5
12.5
45
16.6
15.2
14.0
50
18.5
16.9
15.6
100
36.9
33.83
31.2
2-7.2 Line Loss
a.
The following tables compare approximate hoseline lengths with flow rates and the required pressure to flow
through that length.
2-52
|
