Schwing SPB 28, Operation Manual

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APPEN D IX
700Apndx.fm
PAGE 77
S AF ETY M AN U AL
Concrete Pressure
The force per square area that is exerted on the concrete. The concrete pressure will always be a
ratio in direct proportion to the hydraulic oil pressure on the concrete pump circuit.
See Also :
Maximum Pressure
Conductors
Materials that will conduct electricity. Copper, silver, aluminum, gold, steel, and water are con-
sidered GOOD conductors of electricity. Air, fiberglass, rubber, ceramics and glass are consid-
ered POOR conductors. All of these conductors have a resistance to the flow of electricity that
can be measured in terms of ohms per linear foot. As voltage gets higher, more current flows
through the same resistance. In the case of high-voltage electric wires (8000 volts, for example)
even the poor conductors will carry enough current through your body to ground that you could
be killed. (As little as 35 milliamps can cause fibrillation of the heart.) Some conductors, like air,
resist electricity very well; but if the voltage gets high enough, current will flow (lightning is a
good example of this).
See Also: Electrocution
Decibels
One tenth of a bel. Abbreviated dB. It is a measurement of sound volume. As it applies to con-
crete pumps, it is a measurement of the sound pressure level one meter away from a noise source.
O.S.H.A. has developed guidelines for time limits on exposure to sound at different volume lev-
els. The chart can be found on page 37 of this
Safety Manual .
Drive Engine
The primary source of power for a hydraulic system. Typically, the word “engine” denotes and
internal combustion device, whereas the word “motor” denotes an electrical device.
Electrocution
Made from the words “Electric” + “Execution.” It means death by electricity. See Also: Conduc-
tors
End Hose
A flexible concrete hose that has one end coupling.
Foreign Material
Material that was never intended to be pumped, which ends up in the concrete hopper. Examples
of foreign material include: small animals; hammers; ready mix truck fins; unmixed clumps of
cement; hardened concrete that breaks away from ready mix truck fins; and soda pop cans. These
items could create a blockage if pumped.
Go-devil
A plug made from a rubber composite, usually with several fins that expand to seal when pres-
sure is applied. They are intended to be inserted in a steel delivery pipeline and pushed with
water or compressed air for the purpose of cleaning the pipe.
See Also: Sponge Ball
Guide
An assistant brought in to help in backing up a truck or trailer, or to help in other circumstances
when the driver cannot see enough to assure safety.
See Also: Signalperson
High Voltage
For the purposes of this Safety Manual , anything over 28 volts is to be considered high voltage.
In the U.S., electrically driven concrete pumps normally operate the motors at 480 volts AC
(high voltage) and the motor controls at 24 volt (low voltage). When dealing with power lines in