The inspection and testing of emulsion cranes (cranes used in emulsion environments) after installation should be carried out in combination with four aspects: mechanical structure, hydraulic system, electrical safety, and emulsion environment adaptability. The specific methods are as follows:

1、 Mechanical structure inspection: ensuring foundation safety

Appearance and size inspection

Metal structure: Use a tape measure and laser rangefinder to measure the geometric dimensions of the main beam, support legs, and boom, and compare them with the design drawings to confirm a deviation of ≤± 2mm (GB/T 6067.1 standard).

Weld quality: Magnetic particle testing (MT) or ultrasonic testing (UT) is used to inspect the welds, with a focus on checking the main beam butt welds and leg connection welds. The defect level must comply with ISO 5817 Class B standard.

Connecting components: Use a torque wrench to check the pre tightening force of bolts and pin shafts. The torque error of key parts (such as slewing bearing bolts) should be ≤ ± 5%.

Inspection of walking and operating mechanisms

Track system: Check the straightness and span deviation of the track (≤± 3mm), use a level to check the elevation difference of the track (≤± 2mm), and confirm that the rail stopper and anti-collision device are securely installed.

Wheel set: Check the wear of the tread surface (≤ 5% of the original diameter), the meshing clearance of the open gear (0.3-0.5mm), and the integrity of the coupling protective cover.

2、 Hydraulic system testing: ensuring power stability

Sealing integrity test

Pressure test: Start the hydraulic pump and gradually increase the pressure to the rated pressure (such as 16MPa), hold the pressure for 5 minutes, observe the leakage of the oil cylinder and pipeline joints, and ensure that the leakage rate is ≤ 3 drops/minute.

Oil cleanliness: Sampling and testing for hydraulic oil particle contamination (ISO 4406 standard ≤ 18/16). If emulsion residue causes oil emulsification, it needs to be replaced immediately.

Action performance verification

Empty load test: Operate the lifting, variable amplitude, and rotating mechanisms three times in each direction, with a cumulative time of ≥ 5 minutes. Confirm that the action is smooth and there is no jamming, and the braking distance is ≤ 0.1m.

Load test: Lift the rated weight (such as 10t), repeat the lifting and lowering actions 3 times, check the pressure fluctuation of the hydraulic system (≤± 5%), and the oil temperature rise is ≤ 15 ℃ (when the ambient temperature is 25 ℃).

3、 Electrical system testing: ensuring safety control

Insulation and grounding test

Use a megohmmeter to measure the insulation resistance (≥ 2M Ω) and grounding resistance (≤ 4 Ω) of the motor and control cabinet, with a focus on investigating the risk of short circuits in the circuit caused by emulsion splashing.

Functional verification of safety devices

Overload protection: Simulate 1.1 times the rated load (such as 11t), test the torque limiter alarm and power-off function, with an error of ≤± 3%.

Limit switch: Trigger the lifting height and amplitude limit switch, confirm that the mechanism stops immediately without delay or misoperation.

Emergency stop button: Press the emergency stop button and verify that the power outage time of the entire machine is ≤ 0.5 seconds. After recovery, manual reset is required.

Lighting and Signal System

Check the brightness of the cab lighting (≥ 100lx), ensure that the warning lights and buzzer are working properly, and verify the waterproof performance (IP55 level) during the rainy season.

4、 Load test: Verify comprehensive performance

No-load test

Run each mechanism for a cumulative time of ≥ 10 minutes, confirm that there are no abnormal vibrations or noise (≤ 85dB), and that the brakes do not slip or slide.

Load test

Lift the rated weight (such as 10t), perform a combination of lifting, lowering, rotating, and walking actions, repeat each action 3 times, and detect the structural deformation (vertical deflection of the main beam ≤ L/700, L is the span).

Static Load Test

Suspend 1.25 times the rated load (such as 12.5t), hover 100-200mm above the ground for 10 minutes, check that the main beam and support legs have no permanent deformation (monitored with a laser rangefinder), and that there are no cracks in the welds.

Dynamic load test

Suspend 1.1 times the rated load (such as 11t), perform lifting, braking, and rotating composite actions, check the impact load of the detection mechanism (≤ 1.5 times the rated load), and ensure that no components are detached or damaged.

5、 Special testing for emulsion environment

Anti corrosion performance verification

Spray emulsion (pH 6-8) on steel structures such as frames and legs, and check for paint peeling and rust after 72 hours, with a focus on inspecting welds and bolt connections.

Waterproof testing of electrical system

Spray the control cabinet and sensors with a high-pressure water gun (pressure 0.3MPa) for 10 minutes to verify the IP65 protection level, and there is no water ingress or short circuit phenomenon.

Lubrication system adaptability test

Replace the waterproof grease (NLGI grade 2), check the lubrication of the pulley assembly and bearing seat after 50 hours of operation, and confirm that there is no grease deterioration caused by emulsion invasion.

The main equipment produced by Hebei Makita: stage electric hoist, electric chian hoist, wire rope electric hoist，Hand chain hoist, lever hoist, pneumatic hoist and other lifting equipment