Schwing SP 500 - Pumping the Job

73
Operation
SP 500 / 750-15 / 750-18 / 1000 / 1250 Operation Manual
• With the cement washed to the bottom of the hop-
per, start the machine. Follow the “Starting the
Machine” on page 70. Press back and forth,
between the Concrete Pump Forward and Con-
crete Pump Reverse button (Figure 16) to cycle
the Rock Valve a few times. This will agitate the
mix a little more. Do not try to pump this mix until
you can add concrete.
ACC2ACC1
ACC3
ACC
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Concrete Pump
Forward
Concrete Pump
Reverse
Figure 16
Rear Operator Panel
• After the correct amount of slurry has been placed
in the hopper, direct the rst ready-mix truck to
backup to the hopper. Do not stand between the
ready mix truck and the concrete pump. You could
be crushed between the machines.
Never allow anyone to stand be-
tween the concrete mixer truck and
the pump. Crushing hazard.
• Look at the concrete before putting it into your
hopper. If the mixing ns of the truck are badly
worn, the rock, sand, cement, and water will not
be properly mixed. Do not allow a chute full of gray
rocks to be put into your hopper; you will almost
certainly plug the line before you get concrete out
of the pipe. If the rst chute full is all rock, have the
driver dump it o󰀨 to the side and show you the next
chute full. The second chute full will almost always
look much better than the rst. If it does not, dump
it to the side, too. You will learn by experience
what mixes can and cannot be pumped. When the
mix looks good, place the pump in forward using
the Concrete Pump Forward Button. Take a cou-
ple of strokes to get some of the slurry into the
pipeline ahead of the concrete. Position the Rock
Valve so the open cylinder is on the opposite side
of the hopper from the ready-mix chute, and shut
o󰀨 the pump. This allows the concrete to push the
remaining slurry, below the Rock Valve, into the
open cylinder. It also helps to place the agitator
in reverse to pull the rocky part of the rst chute
full of concrete toward the end of the hopper, and
direct the creamy concrete below the Rock Valve.
Have the driver ll the hopper, and as the slurry
is pushed into the open cylinder, you can put the
pump in forward and begin pumping.
• Pump slowly and watch the concrete pump circuit
pressure gauge until the slurry starts to escape
from the pipe or hose. If the line plugs, immedi-
ately switch the pump to reverse mode, and notify
the ready-mix driver to stop dumping. To remove
the plug, rock the concrete by alternately pumping
a few strokes in forward and a few in reverse, or
remove the plug manually. Rocking the concrete in
forward and reverse usually only works well when
pumping vertically, so gravity can help to create a
vacuum in the line.
Expulsion hazard. Never remove a
clamp from, or open a pressurized
pipeline.
You must not open a blocked pipeline without rst suck-
ing the concrete back into the hopper. Operating the
pump into reverse for several strokes will release the
pressure on the blockage. Understand the safety rules
for opening a blocked pipe explained in the Safety Man-
ual.
• Once concrete has emerged from the point of
discharge, stop pumping. Wait for the start signal
from your spotter before you start pumping.