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PAGE 30 — MAYCO C-30HDNI (PRECISION) PUMP — OPERATION AND PARTS MANUAL — REV. #7 (04/03/12)
C-30HDNI (PRECISION) PUMP — OPERATING INFORMATION
Pumping Tips
1. The effects of heat and excessive time on concrete: Hot
concrete, commonly referred to as a hot load, is concrete that
has been in the redi-mix truck in excess of 2 to 3 hours. On a
hot day, this amount of time is even less. A brief explanation
of why heat and time affect concrete:
Concrete starts setting by drying up through a chemical
reaction. The catalyst to this reaction is heat. When pumping
a hot load, it is important to remember that when you have to
stop pumping for any reason, add water to the concrete in the
hopper and hand mix and move concrete in the hose every
5 minutes. If the shut down time becomes too long, wash out
immediately.
All admixtures will be shown on the
redi-mix concrete ticket. Before start-
ing the pumping job, ask the driver of
the redi-mix truck to see the concrete
ticket and note the admixtures that
exist and take the proper action.
3. When pumping long distance or pumping stiff mixes, you can
expect a drop in volume compared to shorter lines and wetter
mixes due to the change in valve efficiency or cavitation.
4. Leaking manifold seals or hose coupling gaskets which leak
water can cause separation and subsequent jamming at that
point.
5. Damaged hoses with internal restrictions can cause block-
ages.
NOTE
If you repeatedly pull the throttle all the way out and try to force
your pump to push through
blockages
due to separation of
material in the hose or manifold, you will soon have
breakdowns and costly repairs which are not covered under
warranty.
If a blockage occurs, find where it is and clear it before further
pumping. DO NOT increase the engine speed to clear the
blockage. Increasing the engine speed will only compound
the problem.
WARNING - Hose Blockage Hazard
It will be necessary at times to move your pump from one job
site location to another. Before moving the pump, make sure to
pump the remaining concrete out of the hopper. Moving the
pump with a
full hopper
of concrete can cause severe damage
or breakage of the axle and axle springs, excess strain and
pressure on the hub and bearing assembly.
WARNING -
Moving The Pump On The Job Site
New Pumps
All new pumps are “
water pressure tested
” at the factory before
shipment. This procedure permits a thorough inspection of the
entire drive system and valving under simulated full load condi-
tions.
The pump owner can do the same by attaching an adaptor couple
to the end of the discharge cone; e.g., the use of a standard 2 in.
pipe cap with a 3/8 in. hole drilled in the center, screwed on to the
end of the hinged cone or reducer at the pump.
Fill the hopper with water after making sure that all sand and rock
have been removed from the manifold. Operate the pump at full
throttle and the 3/8 in. diameter hole restriction will create sufficient
back-pressure to make a thorough inspection of all moving parts.
2. ADMIXTURES
Remixtures that are designed into the concrete mix by the
redi-mix company or an architectural engineering company.
This section lists common admixtures and a brief explanation
of their functions:
A. Pozzolith 300 – or the equivalent acts as a water
retarder and a lubricant. On a lean mix, long pushes, stiff
mixes, and vertical pushes, Pozzolith 300R helps
pumpability.
B. MBVR – air entraining, acts as a lubricant.
C. Calcium Chloride – commonly referred to as C.C., is
used as an accelerator. When pumping a load with
calcium chloride, it is recommended that you wash out
if the waiting time between delivery trucks becomes too
long.
D. Super Plasticizers – acts as an accelerator. The
concrete will look very wet after the super plasticizer is
added, but will begin to set up very fast. Wash out
immediately if you do not have a truck waiting. Super
plasticizers are used mainly on commercial jobs.
E. Red Label – acts as a water retarder and an accelerator.
Red label will be used mainly on commercial jobs.
F. Fly Ash – is used to help increase the strength of the
concrete and decrease the cement content per yard. This
is one of the most common admixtures used.