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MAYCO C30HDGA CONCRETE PUMP • OPERATION MANUAL — REV. #1 (09/09/19) — PAGE 29
OPERATION
1. Disconnect the hoses from the pump and wash the
pump out immediately. For example: If you had 200 ft.
of system out, you would disconnect each hose.
2. Reconnect the first hose and fill the hopper with water.
DO NOT try to push all the concrete out of all of the
hose lines at one time.
3. Clean it out by pushing water through the first hose off
the pump, then continue progressing through all the
hoses, until all the system is clean.
4. If waiting time is excessive, it would be wise to wash
out the pump and hoses and start over when the new
truck arrives. This can be avoided by being observant
to the pump and system, also taking into consideration
the above factors affecting the mix.
DOWNHILL PUMPING
Downhill pumping can be difficult on some jobs. It is
suggested that a sponge 2”x 4”x 6” be placed in the hose
before the start of pumping. Wet the sponge before placing
it in the hose. Reference the Operating Suggestions at the
start of this section for slurry procedures.
The reason for using the wet sponge is to keep the slurry
from running too far ahead of the concrete and so reducing
the possibility of separation. When the pump is stopped, the
material can flow slowly down, due to gravity, and cause
the hose to collapse.
When pumping is resumed, you can expect a blockage at
the point of hose collapse. To prevent this from happening,
the hose can be “kinked off” at the discharge end when the
pump is stopped to prevent the gravity flow of the material
in the hose.
The use of stiffer mixes when pumping down-hill will
decrease gravity flow of the material in the hose and
will assure a smoother operation between the cam roller
bearing and cam plate. As with any job, make sure that
the hose and the couplings are in good workable shape.
VERTICAL PUMPING
When pumping vertically up the side of a building, above
40 feet, we would recommend the installation of steel pipe
securely fastened at intervals as necessary to support the
pipe. Ninety degree, long radius pipe sweeps should be
installed at the top and bottom of the steel line.
Use a 25 ft. hose, or short section, off the pump; and for the
balance of the horizontal distance to the vertical line, use
steel pipe. This type of installation has been satisfactory on
many jobs being pumped in excess of 100 feet high. Line
pressures are always less using steel pipe as compared
to hose.
When pumping vertically using all hose, it is recommended
not to go higher than 50 feet with hose. The hose should be
tied off at intervals of 10 feet, if possible. Special attention
should be given when tieing the hose off at the top as
the hose will have a tendency to stretch when filled with
concrete. This will increase the possibility of a blockage at
the point where the hose is tied off. To avoid this, a long
radius of 90 degree elbow is recommended. The suggested
place to tie off is on the hose, under the clamp.
VALVE SEATS
If the volume at the end of hose starts to decrease gradually
and eventually almost stops, it is quite likely that the valve
seats have had excessive wear and need replacement.
Once they have reached a certain wear point, they may
“channel out” rapidly and material will reciprocate past the
ball on each stroke.
The hollow steel ball should be replaced when it starts
to show dents or appears to be badly worn. Sand and
aggregate materials in some areas are extremely sharp and
hard and therefore highly abrasive. Under these conditions
when pumping stiff mixes, or to high elevations which cause
line pressures, it will be noted that valve components may
have short wear life.
If this condition exists, it is advisable to remove the manifold
only, and inspect the lower seat at the end of each day. If it
appears that the seat is beginning to “channel out", replace
before starting the next day’s pour.
The upper valve seat can be inspected after each washout
by running your finger around lower edge of seat where the
ball makes contact. You can reach this from the inside of
the hopper. Be sure that the engine is turned off.
NOTICE
It is strongly recommended that steel pipe be used on
all vertical pumping for safety and convenience.