Appendix
Operation Manual -
SP 30578
revDate
When the output line intersects the pipeline diameter
that corresponds to your job, draw a line straight down
into the lower right quadrant, as shown in Figure 52.
3. The lower right quadrant refers to the
proportional value of your pipeline. It is a way of
taking into account not only the length of the
pipeline, but also the number of bends, the
increased resistance of flow in rubber hose, and
other factors. It is more a measure of the resistance
to flow than a measure of length. In calculating the
proportional value of your pipeline, always apply
the following criteria:
• each 90° bend with a radius of 250 mm (boom
elbow) = 3.5 feet
• each 90° bend with a radius of 1 meter (long
sweep) = 10 feet
• each 30° or 45° bend with a radius of 1 meter
or 250 mm = 3 feet
• each section of rubber hose causes three times
as much resistance as the same length of steel
pipe (e.g., 12 ft. of rubber hose has the same
resistance as 36 ft. of pipeline)
• Figure all horizontal and vertical distances
equally. The increased pressure required to
push concrete vertically is accounted for by
adding pressure, not distance. An example
pipeline is shown below (Figure 53).
40 ft.
hose
400 ft. pipe
70 ft.
level
difference
mavprop.eps
Example: You must go 400 feet through the pipeline, then through 40 feet of rubber hose.
Calculate the proportional value as follows:
40 10-foot pipe sections = 400. feet
3.5 x 2 = 7 feet (for 90˚ elbows)
40 x 3 = 120. feet (for the rubber hose)
Total = 527.0 feet
Round down to 500 feet to make it easy to use the chart (Figure 54).
elbow - 90°, r = 250 mm...3.5 feet
elbow - 90°, r = 1 meter...10 feet
elbow - 30° or 45°, r = 250mm or 1 meter...3 feet
Figure 53
Calculating proportional values
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