TM 10-4320-345-13
2-11. ASSEMBLY AND PREPARATION FOR USE - cont.
NOTE
If the level of ground profile is below base of pump spacing triangle,
extend the line of the spacing triangle hypotenuse until it crosses the
ground profile
(10)
To determine the location of the second boost pumping station, place the zero mark of the spacing
triangle on the first boost pumping station mark of the ground profile. Mark the point at which the
spacing triangle hypotenuse crosses the ground profile. Mark the point at which the spacing triangle
hypotenuse crosses the ground profile. This will be the location of the second boost pumping station.
Locations of successive boost pumping stations are determined in the same way.
(11)
After locations of pumping stations have been plotted, check ground profile for any sharp declines in
elevation along hoseline route. An excessive drop in elevation will significantly increase the pressure
of water as it flows downhill. If pressure builds to 225 psig, hoseline can rupture and equipment failure
will result therefore, when the ground profile Indicates a sharp elevation drop along the route, a
pressure reducing valve must be installed in the hoseline.
(12)
To determine the location of the pressure reducing valve, refer to the ground profile and proceed as
follows, (refer to figure 2-11).
(a)
Mark crest of hill on ground profile.
(b)
Draw a vertical line downward from the hill crest.
(c)
Determine location of pumping station closest to the crest (on uphill side).
(d)
Draw a horizontal line outward from pumping station until it intersects the vertical line.
(e)
Measure footage of horizontal line outward from pumping station until it intersects the vertical
line.
(f)
Using formula provided below, determine total hoseline footage between pumping station and hill
crest.
Total hoseline footage =
(a = horizontal line footage)
(b =vertical line footage)
(g)
Using formula provided below, determine friction loss of total hoseline footage in terms of vertical
feet:
Total hoseline footage x 0.024 = Vertical feet of friction loss in hoseline.
(0.024 = friction loss conversion factor)
2-28
