Schwing SPB 28, Operation Manual

Page: 92 / 216

GENERAL RULE S
PAGE 62
700+ smgr.fm
S AF ETY M AN U AL
16.13
Do not let the concrete level in the hopper become low! If air is
sucked into the material cylinders, the pump will compress the air. Compressed
air always poses a hazard as it is expelled from the hopper or the delivery pipeline
(Figure 80). If air is taken into the material cylinders, take the following steps to
minimize the hazard:
1. Stop the pump immediately. Hit the emergency stop switch (E-Stop) if
that is the quickest way to stop the pump. There will be an expulsion of
compressed air the next time the concrete valve shifts. If possible, fill the
hopper with concrete to help contain the expulsion. Do not put your face
directly over the hopper.
2. Alert the operator of the problem. It is the operator’s job to know the pro-
cedures for safe removal of air from the pump and delivery system. These
procedures include pumping in reverse for a couple of strokes.
3. Persons standing at the discharge end or near the delivery line must be
warned to move away until all of the air has been purged. Warn them to stay
a reasonable and prudent distance beyond the reach of the end hose or point
of discharge (Figure 80).
4. When the pump is restarted, don’t assume that the first little air bubble is the
end of the compressed air.
5. Do not allow anyone near the discharge until concrete runs steadily from
the end and there is no movement of the delivery system.
6. If workers are positioned in high or precarious places, warn them to expect
a loud sound as the air escapes the pipeline. (Warn them even if they are
well away from the discharge.) That way, it’s possible to prevent the worker
from falling as a result of being startled by the noise.
WARNING
hosepop7.eps
Figure 80
Remove everyone from the
discharge area whenever the
pump is first starting, restarting
after moving, or if air has been
introduced into the line