Schwing SPB 28, Operation Manual

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APPEN D IX
PAGE 76
700Apndx.fm
S AF ETY M AN U AL
I X. Gl ossar y O f Te r m s
Accumulator
A hydraulic device that stores fluid power energy in much the same way that a battery stores
electrical energy. Because an accumulator will store energy, it MUST be drained and depressur-
ized before work begins on an accumulator-equipped actuator or hydraulic system.
Agitator
A device that sits in the concrete hopper to keep concrete moving; preventing it from setting. It is
typically a rotating shaft to which several paddles have been mounted.
See Also: Hopper Grate
ASME B30.27
A safety standard for material placement systems (concrete pumps and material placement con-
veyors) that has been accepted by ANSI as an American National Standard.
Blanking Plate
Also known as a blanking plug or end cap. Its purpose is to prevent material from falling out
of the delivery system when moving a boom with a full pipeline over personnel or property.
Blockage
Simply put, if the pump is pushing and concrete fails to come out at the point of discharge, it is
called a blockage. Blockages can be removed with pump pressure, by rocking the pump between
forward and reverse, or some other remedial measure. If the blockage can’t be removed in such a
manner, it’s called a plug.
See Also: Plug, Rock Jam. The causes of blockages are detailed in sec-
tion 8.21 of this Safety Manual . In all cases, blockages create a hazard by causing high concrete
pressure, combined with the sometimes uncoordinated efforts of untrained workmen to remedy
the problem.
Bulk Density
The mass of a substance per volume. For example, one cubic foot of air weighs much less than
one cubic foot of water. One cubic foot of lightweight concrete weighs less than one cubic foot
of steel-entrained concrete. We could say that steel-entrained concrete has a higher bulk density
than lightweight concrete. All calculations for the operation manuals and specifications of con-
crete pumps are based upon 150 pounds per cubic foot, which is the approximate mass of hard
rock (normal) concrete.
Certified Operator
An operator that has been issued a certification card by the American Concrete Pumping Associ-
ation. There are several classes of certification, each relating to a different category of pump. For
an operator to become certified, he (she) must: pass the written tests regarding operation, setup,
and clean-out for each category of pump; pass the technical and the safety rules tests which are
common to all certification categories; meet the experience requirements set forth for each cate-
gory; and maintain a safe and clean driving record. The certification card only certifies that the
operator has passed a written test administered by an ACPA certification proctor and does not
attest to their ability to operate a concrete pump.
See Also: Qualified Person, Qualified Operator.
Concrete Delivery Hose
A flexible concrete hose that has two end couplings.