Daily maintenance of fine aggregate concrete pumps refers to routine maintenance during use. The work includes checking, cleaning, lubrication, tightening, adjustment, leakage detection, and replenishing hydraulic oil, etc.
1. Hydraulic Element Inspection
- If a fault is found, check the cause and repair the entire circuit before performing any operation.
- Identify and eliminate external oil leaks.
- Check safety valves, hydraulic system steel pipes and hoses, connectors, and cylinders for any wear or cracks (a burst pipe can have serious consequences).
- Inspect the pipeline from the safety valve to the cylinder inlet to ensure no external leakage or deformation due to impact and wear. Ensure all connectors are intact and fully tightened.
- Immediately replace any damaged pipes.
- Do not alter original settings: all adjustments and calibrations must be completed by professionals.
2. Lubrication Inspection
- Ensure that the grease inside the lubrication pump is always sufficient and clean. There should be no overflow at the joints of the lubrication pipeline.
- Regularly check the lubrication status of all moving parts. If any lack of oil is detected, stop the machine immediately to prevent accidents.
- When the lubrication distributor indicator rod pops out, clear the blockage in the corresponding lubrication pipeline.
- Check the effectiveness of the centralized lubrication system daily.
- After the grease pump is emptied, it may be difficult to pump out the newly added grease due to air bubbles. In this case, open the pump outlet and run the grease pump until grease flows out again, then reconnect the pipeline.
- Lubricate lubrication points not covered by the centralized lubrication system with a manual grease gun.
- Check the levels of oil and lubricants.
- Apply grease to mechanical structural components to prevent surface exposure. All components of long-term stored equipment should be fully lubricated.
3. Tightening
Frequently inspected and tightened bolted connections include:
- Concrete cylinder body, tie rods, bolts, and nuts
- Cylinder head joint and frame connection bolts
- S-valve outlet connection bolts
- Main cylinder end connection bolts
- Oil pump suction and discharge ports connected to pipelines
- Valve box and hopper fixing bolts
- Stirring blade fixing bolts
- Valve box fixing bolts
- Fixing bolts of each oil pump, pump seat, pump seat and base plate, oil motor and bracket
- Clamping bolts of conveying pipelines
4. Leak Detection and Handling
Main leak detection areas include:
- Level gauge, drain plug, oil pump, oil motor shaft ends and shell mating surfaces, cylinder cap mating surfaces, cylinder piston rod extension area, mating surfaces of various hydraulic valves, adjustment handle extension area, oil pipe joints, cylinder
5. Adjustment
This refers to maintenance adjustments and does not include performance tuning.
After working for a period of time, the S-tube, eye plate, and wear ring will develop gaps due to wear. If the gap is too large, it will affect normal pumping. Therefore, timely adjustments and replacements are necessary. Wear gaps can be measured in a cleaned hopper.
When the gap exceeds 0.5mm, adjust the eccentric bolt behind the S-tube axis to adjust the gap between the S-tube wear ring and the eye plate to 0.1-0.2mm. If the wear ring and eye plate are pressed too tightly, the S-tube will not swing properly.
After multiple gap adjustments, if further adjustments cannot be made and the gap exceeds 0.7mm (or any groove exceeds 1.5mm), consider replacing or repairing the eye plate and wear ring.
6. Daily Maintenance Combined with Pumping Construction
(1) Pre-start Inspection and Maintenance
- Motor inspection should show good appearance, reliable fixation, undamaged motor fans, no looseness, and no friction with the cover.
- Power supply and transmission line inspection. Cables and power lines should be securely connected.
- Electrical control box inspection. Wiring should be intact without damage or disconnection; the interior should be clean, dry, and free of debris; instruments, indicator lights, switches, etc., should be complete and in good condition. All switches should be in the specified state before startup, i.e., the pressure test switch is in the off position; the plate valve reverse switch is in the forward position.
- Oil level inspection. The oil level should be in the middle position on the level gauge.
- Oil quality inspection. It should be yellow and transparent, without foaming or turbidity.
- Observe the liquid in the water tank for 10 minutes. The liquid level should not drop significantly; otherwise, check the reason for the water leak and make corrections.
- The hopper should be cleaned, with no concrete residue or debris; stirring blades should be securely fastened, in good condition, and without damage or deformation.
- The valve box interior should be clean, with no concrete residue or debris, and the discharge door should close tightly and reliably; the gap between the wear ring and the eye plate should meet requirements.
- The fixation of each pump, oil motor, valve, and connection to the oil pipe should be secure and well-sealed.
- Before connecting the pipe, inspect each pipe to ensure it is clean, smooth, with no cracks or severe dents; clamps and their connecting screws should be in good condition and clean; rubber sealing rings in the clamps should be intact and elastic, with no cement residue; the pipeline should be laid as flat as possible, with secure connections and reliable support, avoiding contact with objects harmful to the pipe fittings.
(2) Fine Aggregate Concrete Pump No-load Operation Inspection
- Test the rotation direction of the motor.
- Press the pumping button. The coordination between the concrete cylinder piston push and the S-tube directional change should be correct, and the pushing frequency should meet requirements.
- Test the main oil pressure setting value, which should meet the requirements of Chapter Two.
- Press the piston reverse button to test the reverse pump control. Both the reverse and return of the piston should be flexible and reliable.
- Test the forward and reverse stirring controls, which should be flexible and reliable.
- Check electrical indicator lights and hydraulic pressure gauges, which should indicate correctly without faults.
- Test the remote control button for independent control of pumping and stopping. Alternate operation between remote control and electrical control panel should meet usage requirements.
- Run no-load for half an hour. Check all moving parts for abnormal sounds or violent phenomena; the hydraulic system should have no external leakage, and the oil tank oil level and oil temperature rise should be normal, with no foaming of the oil; the water tank water level should not drop significantly. Then stop the machine.
(3) Inspection and Maintenance During Pumping Construction
- Check the current and temperature rise of the motor, both of which should be within the specified range.
- Instruments, indicator lights, and all operating components should function well.
- Operate in the prescribed sequence to avoid starting under load.
- Keep electrical equipment clean and dry; protect cables and remote control lines from damage.
- Check the oil tank oil level, oil quality, and oil temperature, all of which should meet requirements.
- The pressure, flow, noise, and temperature rise of the oil pump and oil motor should all be within the normal range. Stop the machine immediately if the oil temperature reaches 70°C to cool down.
- All valves, accumulators, and pressure gauges should function well and meet system operation requirements.
- Hydraulic pipe connections should be secure with no external leakage.
- If there is a large amount of cement slurry in the water tank, check whether the concrete piston is damaged.
- In cold seasons, take thermal insulation measures or add 20 liters of antifreeze to prevent the water tank from freezing.
- Remove oversized aggregates or other debris on the grid at any time; do not arbitrarily remove the grid.
- Prevent foreign objects such as rebar from entering the hopper. If the stirring shaft is stuck, check the cause and remove obstacles promptly.
- Timely check the automatic lubrication equipment to ensure lubrication of all lubrication points of the distribution valve and the stirring part.
- Maintain the closure of the discharge door. If there is water leakage, slurry leakage, or air leakage, check and handle immediately. After opening the discharge door, clean the sealing surface and seal ring thoroughly before closing it tightly.
- Pipeline joints should be secure and sealed. If there is water leakage or slurry leakage, dismantle and check promptly.
- Check the support and fixation of the pipeline. If the padding is damaged due to vibration during pumping operations, restore and reinforce it promptly.
(4) Post-construction Inspection and Maintenance
- After washing with compressed air or high-pressure water, if there will be no pumping operations within two days, dismantle the pipe fittings step by step and wash them thoroughly with water, including the inside and outside of the pipe fittings, clamps, and sealing rings.
- Conduct a comprehensive inspection of all pipe fittings once and store them separately according to specifications and condition.
- Wash the hopper, valve box, concrete cylinder, and exterior of the pump thoroughly.
- Wipe off water from covers and electrical boxes and check for water ingress in the electrical box and take appropriate action.
- Disconnect the power supply and remove cables, remote control lines, etc.
- Inspect all parts for any damage.
- Handle problems discovered during operation.
- Clean and maintain random tools.
- Cover and protect the fine aggregate concrete pump.