TM 10-4320-317-13
(1) Mark crest of hill on ground profile.
(2) Draw a vertical line downward from the hill crest.
(3) Determine location of pumping station closest to the crest (on uphill side).
(4) Draw a horizontal line outward from pumping station until it intersects with the vertical line.
(5) Measure footage of horizontal line and footage of vertical line.
(6) Using formula provided below, determine total hoseline footage between pumping station and hill crest:
Total hoseline footage = a2 + b2
(a = horizontal line footage)
(b = vertical line footage)
(7) 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)
(8)
Using formula provided below, determine total feet of friction loss:
Vertical feet of
Feet of elevation
friction loss in
+
between pumping station
=
Total feet of friction loss
hoseline
and hill crest
friction loss
(9) Using formula provided
below, convert total feet
of friction loss into psi:
Total feet of friction loss = friction loss in psi
2.31
(2.31 = psi conversion factor)
(10) Using formula provided below, determine existing psi at hill crest:
150 psi - psi of friction loss = psi at hill crest
(150 psi = pumping station discharge pressure)
(11) Using formula provided below, determine allowed additional psi before safety limit is reached:
225 psi - psi at hill crest = Allowed additional psi before reaching safety limit
(225 psi = safety limit of pressure)
(12) Using formula provided below, convert allowed additional psi into vertical feet:
Allowed additional psi X 2.31 = Allowed additional vertical footage before reaching safety limit
(2.31 psi = vertical footage conversion factor)
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