Multiquip ST70 - Manual (Page 27)

ST-70 — PARTS & OPERATION MANUAL — REV. #4 (05/29/07) — PAGE 27
ST-70 — OPERATING PROCEDURES
WARNING: Common sense tells us that if you
drive a truck into a “brick wall,” something is
going to be damaged. The same holds true
with your concrete pump. If you repeatedly pull
the throttle all the way out and 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 the warranty. If a blockage
exists, find where it is and clear it before further pumping. Do
not use extra horse power, it will only make it worse.
1. When pumping long distances or pumping stiff mixes, you
can expect a drop in volume, compared to shorter lines and
wetter mixes due to higher pumping pressures and
cavitation.
2. Leaking hose coupling gaskets (which leak water) cause
separation and subsequent jamming at that point.
18 Priming the Pump and Delivery System with Slurry.
It is CRITICAL to the successful operation of a concrete
pump that the manifold and all delivery hose, pipe and
elbows are coated with a film of lubrication BEFORE
you attempt to pump concrete. Failure to properly
prepare the pump and system will result in a “dry pack”
of concrete, blocking the shuttle valve tube or delivery
line.
18.1 With the entire delivery system connected to the pump.
Except for the first hose. Pour 5 gallons of water into the
second hose and push in your clean out ball and
reconnect. This will help hold back the prime.
18.2 What you can use to mix the prime:
There are several things you can use for the prime. Here
are a few. Cement and lime at a 50/50 mixture, slick pac,
bentonite clay.
NOTE: The bentonite is not compatible with concrete.
Do not pump it into the forms discharge it out of the
formed area.
Mix the prime to the consistency of a smooth batter.
18.4 Position the first ready-mix truck at the hopper. Check
the concrete. Do not discharge concrete into hopper at
this time.
18.5 Pour the prime into the first hose and connect it to the
pump.
NOTE: You should use two 5 gallon buckets of prime.
18.6 With the pump in FORWARD at 25-30 strokes per minute,
slowly discharge the concrete from the ready-mix truck
into the hopper and completely fill it. Keep the pump
running continuously until concrete is discharging at
the end of the delivery system. If the pump is stopped
during this procedure, a blockage may occur (see page
22, Section 4).
18.7 If it is necessary to replace or add a section of delivery
system, after the initial lubrication procedure, wet the
inside area of the hose, pipe or elbow with 5 gallons of
water per 25 foot length, before adding it to the
system.
19. Waiting for concrete trucks to arrive: If there are delays:
19.1 Stop the pump with a full hopper.
19.2 Run the remixer, alternating forward and reverse,
whenever the engine is running.
19.3 Add water to stiff mixes, if necessary.
19.4 If shutdown period exceeds 3 to 4 minutes, turn off engine
to prevent vibration from separating the mix in the hopper.
Separation will cause a blockage in the manifold when
pumping is resumed.
19.5 Start the engine, cycle the pump slowly 1 or 2 strokes
and run remixer every 10 minutes.
19.6 If shutdown period reaches 1 hour (or less, depending
on the age and temperature of the concrete), pump out
and clean the delivery system and pump. (See page
24 for clean up procedures.)