Operating Guidelines for Concrete Trailer Pumps and Boom Pumps

Proper operation of concrete trailer pumps and boom pumps is essential for safe, efficient, and reliable concrete delivery. Operators should follow the manufacturer's operating procedures and pay close attention to ground conditions, concrete quality, pumping continuity, pipeline pressure, and equipment cleaning.

The following guidelines cover the key procedures for preparing, operating, stopping, and cleaning concrete pumping equipment.

1. Position the Pump on Stable Ground

The concrete pump must be positioned on firm, level, and stable ground.

If the pump has to be parked on a slope, use wheel chocks or suitable wheel restraints to prevent the machine from moving. The inclination of the equipment should not exceed 30°.

For boom pump trucks, the outriggers must also be properly deployed and supported before the boom is extended.

2. Warm Up the Hydraulic System in Cold Weather

When the ambient temperature is low, allow the pump to run without load for a longer warm-up period.

Concrete should not be pumped until the hydraulic oil temperature has reached at least 15°C (59°F). This helps ensure proper hydraulic system performance and reduces the risk of damage caused by operating with cold hydraulic oil.

3. Lubricate the Pipeline Before Pumping

Before pumping concrete, add approximately 10 liters of clean water and 0.3 m³ of cement mortar into the hopper.

If the delivery pipeline is longer than 100 meters, the amount of water and cement mortar should be increased appropriately according to the pipeline length and actual site conditions.

The purpose of this procedure is to lubricate the inside of the delivery pipeline and reduce the risk of initial blockage.

4. Properly Introduce the Cement Mortar

After adding the cement mortar to the hopper, briefly reverse the agitator to lubricate the inner wall of the hopper.

Then run the agitator in the normal direction so that the mortar is gradually fed through the hopper throat into the concrete distribution valve.

When starting the pump, do not pump all of the mortar out of the hopper. Keep some mortar above the agitator shaft level. Once concrete is added, the remaining mortar can be pumped together with the concrete.

This helps maintain adequate lubrication during the initial pumping stage.

5. Maintain an Adequate Concrete Level in the Hopper

During continuous pumping, the concrete level in the hopper should remain above the agitator shaft.

If the supply of concrete cannot keep up with the pumping rate, stop pumping rather than allowing the hopper to run nearly empty.

Maintaining sufficient concrete in the hopper helps prevent air from entering the pumping system and reduces the risk of segregation and pipeline blockage.

6. Control the Feed Rate and Remove Foreign Materials

Do not allow the hopper grate to become overloaded with concrete.

The concrete feeding rate should be controlled so that the agitator can operate properly. Oversized aggregate, foreign objects, and other unsuitable materials should be removed from the hopper promptly.

This helps prevent the agitator, distribution valve, or pumping cylinders from becoming blocked or damaged.

7. Stop Pumping if the Agitator Becomes Jammed

If the agitator shaft becomes stuck or cannot rotate normally, stop pumping immediately.

Do not continue forcing concrete through the system while the agitator is malfunctioning. Identify and eliminate the cause of the blockage or mechanical failure before resuming operation.

8. Stop Pumping if Concrete Segregates

If the concrete entering the hopper shows obvious segregation, stop pumping and allow the concrete to be thoroughly remixed before continuing.

If severe segregation occurs and there is insufficient mortar in the hopper:

• Remove some of the separated coarse aggregate.

• Add an appropriate amount of cement mortar.

• Remix the concrete thoroughly before pumping again.

If necessary, open the inspection window of the distribution valve and completely remove the concrete from the hopper and valve box.

Never force severely segregated concrete through the delivery system, as this can cause serious pipeline blockages.

9. Procedures for Temporary Pumping Interruptions

The interruption of concrete supply should generally not exceed one hour.

If pumping has to be stopped temporarily, perform 2–3 reverse-and-forward pumping cycles approximately every 10 minutes to prevent the concrete from settling and hardening inside the pipeline.

Before restarting continuous pumping, thoroughly remix the concrete in the hopper.

The actual allowable interruption time should also be adjusted according to concrete mix design, ambient temperature, setting time, and site conditions.

10. Restarting After an Interruption in Vertical Pumping

Special attention is required when pumping concrete vertically upward.

After pumping has been interrupted, before restarting the pump, first perform a reverse-pumping operation to draw the concrete inside the distribution valve back toward the hopper.

After the concrete has been remixed, switch back to forward pumping.

This procedure helps reduce the risk of blockage caused by concrete settling in the vertical pipeline.

11. Prevent Concrete Backflow

If the delivery pipeline is equipped with a stop-flow pipe or shut-off device, install the stop-flow rod before finishing the operation.

This prevents concrete in vertical or upward-sloping sections of the pipeline from flowing backward after pumping stops.

Always follow the specific operating procedure provided by the equipment manufacturer for the installed shut-off system.

Pipeline Cleaning Procedures

Proper pipeline cleaning is essential after pumping. Concrete left inside the pipeline can harden and cause blockages, increased resistance, or equipment damage during the next operation.

12. Install the Air-Cleaning Equipment

Before pneumatic pipeline cleaning:

1. Remove the reducer pipe.

2. Remove the remaining concrete from the end of the 6B straight pipe.

3. Install the air-cleaning adapter.

4. Insert a water-soaked sponge cleaning ball into the adapter.

5. Connect the front and exhaust valves and the compressed-air hose.

Make sure all connections are properly secured before introducing compressed air.

13. Install a Safety Cap at the Pipeline End

Install a safety cap at the end of the delivery pipeline, with its opening facing downward.

If the end of the pipeline already points vertically downward or is equipped with a 90-degree downward elbow, a safety cap may not be necessary.

The purpose of the safety arrangement is to prevent the cleaning ball and residual concrete from being discharged in an uncontrolled direction.

14. Clean the Pipeline Using Compressed Air

After all air-cleaning components have been correctly installed, slowly open the compressed-air inlet valve.

The compressed air will push the sponge cleaning ball through the pipeline and discharge the remaining concrete.

If the pipeline is equipped with a stop-flow pipe, first remove the stop-flow rod and securely cover the rod opening. Then slowly open the compressed-air inlet valve.

Compressed-air cleaning must be performed carefully because the cleaning ball and residual concrete can be discharged at high speed.

15. Release Air Pressure Gradually

When the concrete inside the pipeline is almost completely discharged, slowly open the exhaust valve.

This reduces the pressure inside the pipeline and helps prevent the cleaning ball from being expelled violently and creating a dangerous impact at the pipeline outlet.

Operators and other workers should remain clear of the pipeline outlet during the cleaning process.

Cleaning the Concrete Pump

16. Thoroughly Clean the Hopper, Distribution Valve, and Concrete Cylinders

After pipeline cleaning, thoroughly wash the pump itself.

Open the inspection window of the distribution valve and operate the hopper agitator. Perform the appropriate unloaded pumping strokes while continuously flushing water into the hopper and valve box.

Continue washing until the following components are completely clean:

• Hopper

• Agitator

• Distribution valve

• Concrete cylinders

• Other concrete-contacting components

After the internal components have been cleaned, wash the exterior of the concrete pump.

If the pump will remain unused for several days, remove the working-cylinder rubber pistons as required and drain the water system completely.

If the cleaning water is heavily contaminated or muddy, the water system should also be thoroughly cleaned.

Conclusion

Correct operating procedures are critical to the safe and reliable operation of concrete trailer pumps and boom pumps.

Operators should pay particular attention to:

• Stable equipment positioning

• Hydraulic oil warm-up in cold weather

• Pipeline lubrication before pumping

• Maintaining sufficient concrete in the hopper

• Preventing aggregate segregation

• Proper procedures during pumping interruptions

• Safe restarting of vertical pumping

• Preventing concrete backflow

• Safe compressed-air pipeline cleaning

• Thorough equipment cleaning after operation

Following these procedures can significantly reduce the risk of pipeline blockages, equipment failures, and safety accidents while helping extend the service life of the concrete pumping system.

Always follow the specific operating and safety instructions provided by the pump manufacturer, especially for pressure limits, pipeline cleaning, shutdown procedures, and maintenance.