Multiquip ST70 - Manual (Page 30)

PAGE 30 — ST-70 — PARTS & OPERATION MANUAL — REV. #4 (05/29/07)
ST-70 — OPERATING PROCEDURES
14. All new pumps are ‘water pressure tested” at the factory
This procedure permits a thorough inspection of entire
drive system and valving under simulated full load
conditions. The pump owner can do the same by making
an adapter to couple to the end of the discharge cone:
e.g., the use of a standard 2" pipe cap with a #/8" drilled
hole in the center, screwed on to the end of hinged cone
or reducer at the pump. Fill hopper with water after making
sure that all sand and rock have been removed from
manifold. Operate pump at full throttle and the #/8" diameter
hole restriction will create sufficient back pressure to make
thorough inspection of all moving parts.
CLEANING THE PUMP AND DELIVERY SYSTEM
Cleaning the pump is a very important operation as it
determines how the machine will
pump the next time it is used.
At the end of every pour, or because of long delays during a
pour, the pump and delivery system must be thoroughly cleaned
by removing all concrete material.
1. Ensure that there is no blockage in the hose and line (See
page 29, Section 4) or in the shuttle tube (See Page 29,
Section 7). If a blockage exists, clear it.
2. Pump concrete until the opening of the concrete cylinder
intake in the hopper is visible.
3. Stop the pump.
4. Carefully disconnect the first hose joint at the shuttle tube
discharge elbow.
5. Add water to the hopper. Pump and flush clean the entire
hopper, shuttle tube and discharge elbow with water.
6. Scoop out 12 inches of concrete from the inboard end of the
delivery hose. “Cork screw” a 6" x 6" x 8" sponge into the
end of the first hose section. Reconnect the hose to the
discharge elbow.
7. Fill hopper with water. Pump until sponge and clean water
come out the discharge end of the hose and line system.
8. When the Model ST-70 has been used to pump small
aggregate concrete (pea rock, ½" minus) or mixes with
high fines content (60% or more sand) there will be a
tendency for hardened concrete to build up on the inside
surface of the shuttle tube. Therefore, at the end of every
such pour, after the pump and system have been cleaned
and the engine shut off, remove the shuttle tube inspection
plate (See Page 28, Section 7.4) and remove all remaining
concrete.
9. When the Model ST-70 has been used to pump large
aggregate concrete (¾" to 1 ½") follow the instructions in the
above Section 8 once per week.
WARNING
NEVER put your hands or any other parts of
your body in the hopper while the engine is
running or prior to any maintenance, check
the accumulator pressure gauge and make
sure the reading is zero pressure.
NEVER use muriatic acid to clean the pump.
Acid will dissolve the chrome finish on
material cylinder bore and main hydraulic
cylinder rods.
Use only a 2½" diameter clean-out hook when back-
pumping into redi-mix truck. Use a safety chain to secure
the clean-out hook to some solid part of the mixer truck to
prevent hook from jumping off of the drum.
Run the pump at 6 strokes per minute maximum speed.