GB/T 39208-2020 in English

GB/T39208-2020 is my country's first special installation and commissioning standard for retractable full-rotation propeller devices, which is applicable to two typical structures of fixed propulsion motors (vertical/horizontal) and follow-up vertical ones. The standard establishes a complete quality indicator system from the dimensions of base processing accuracy (±5mm), seal ring contact surface flatness (≤1mm), shaft alignment (radial/axial deviation), etc.

1. Base processing stage

It is necessary to ensure that the center line of the machining equipment is aligned with the center line of the telescopic paddle installation base, and the panel thickness is not less than the theoretical value. The sealing ring area is surface treated according to the requirements of CB/T3802.

2. Guide rod installation and debugging

During the full-stroke telescopic test, the gap around the guide rod and the sleeve must be kept uniform, and the thickness error of the adjustment gasket must be controlled within ±0.1mm. The welding of the underwater support seat must comply with the CB/T3558 secondary weld standard.

3. Shaft alignment control

The axial/radial deviation between the output end of the propulsion motor and the input end of the retractable propeller must be checked using a laser alignment instrument, and a secondary alignment review must be performed after launching.

Mooring debugging

Includes 12 core tests:

• Auxiliary system pressure test (30min continuous operation)
• Full rotation effectiveness test (0°-360° response time ≤15s)
• 25%-50%-75% load step test

Navigation debugging

Key verification:

• Dynamic stability at 100% rated power
• Controllable pitch propeller pitch calibration (zero calibration error ≤0.5°)
• Response time of full reverse thrust condition

1. Welding quality control: 100% UT inspection of base welds is required, and acceptance is in accordance with CB/T3559-2011 Level I

2. Bolt preload management: Hydraulic tensioner is required for bolts above M36, and torque deviation is ≤±5%

3. Debugging data record: It is recommended to use the standardized form in Appendix A/B, and key parameters need to be jointly signed and confirmed by the shipowner