GB/T 39184-2020 in English

GB/T39184-2020 standard systematically regulates the entire installation and commissioning process of ROV retractable device and umbilical winch, covering the technical requirements of three types of typical hanger structures (single hanging point type, sliding trolley type, moon pool track type). This standard is applicable to the construction acceptance of ships and marine engineering equipment.

1. Welding quality control

The standard requires the use of symmetrical welding and intermittent welding processes to control deformation, and ultrasonic flaw detection is required inside the weld, and the defect detection rate should be <0.2%. Typical cases show that the moon pool track needs to be aged for 24 hours after welding.

2. Bolt tightening standards

The torque values of bolts made of different materials vary significantly. Take M16 bolts as an example:
- Grade 8.8: 195N·m (dry type)
- 316 stainless steel: 135N·m (wet type)
Use a calibrated torque wrench to tighten in three times.

Mooring debugging phase

• Load test: Static load (10 minutes hold) and dynamic load (3 cycles) tests are required
• Hydraulic system: Safety valve opening pressure deviation should be ≤5% of rated value

Navigation debugging phase

• Wave compensation: Activation depth threshold error should be <0.5m
• Emergency brake: Braking time of the hanger should be ≤2 seconds