CPO CPO Hydraulic Systems & Pump Mechanics 2

Question 1

What is the function of the S-tube valve (rock valve) in a concrete pump?

Accepted Answer

To direct concrete alternately from each cylinder into the delivery pipeline

Answer

The S-tube valve swings between the two pumping cylinders to direct concrete flow into the delivery pipeline during each alternating stroke.

Question 2

What component prevents concrete from flowing backward in the delivery pipeline?

Accepted Answer

Check valve

Answer

Check valves allow flow in only one direction, preventing concrete from reversing back into the pump during each stroke transition.

Question 3

What is the primary purpose of the agitator in the concrete pump hopper?

Accepted Answer

To keep concrete moving and prevent segregation of materials

Answer

The agitator continuously moves concrete in the hopper to prevent aggregate from settling and to maintain workability before pumping.

Question 4

What type of pump is most commonly used in truck-mounted concrete boom pumps?

Accepted Answer

Twin-cylinder piston pump

Answer

Twin-cylinder piston pumps are standard in concrete boom pumps because they generate the high pressures needed and can handle abrasive concrete.

Question 5

How does a concrete pump's stroke counter benefit the operator during a pour?

Accepted Answer

It tracks pumping strokes to estimate volume of concrete pumped

Answer

Since each stroke displaces a known volume, the stroke counter allows operators to estimate total volume pumped and monitor pump performance.

CPO - Concrete Pump Operator Certification Practice Test