What is offshore container?
1.Definition of offshore container
The offshore container is a transportation equipment used in the environment of offshore oil platforms. The total weight is generally less than 25 tons(definied by DNV). It is always carried by a spreader fixed on the lifting lugs.
2. Type of offshore container
1) Offshore containers for transportation, including general containers, open top containers, tanks, bulk containers and special units.
2) Service used offshore containers, for offshore oil platform projects,mostly used as temporary devices,including,laboratory, workshop, warehouse, power workshop, console and cable box(if there is any electrical equipment in offshore container, must carry out safety certification for electrical appliances)
3) Waste skip
3. Special requirements for offshore containers
1) The offshore container is always handled by the lifting lugs, so the general container cannot meet its transportation requirements.
2) The strength of the offshore container should be able to meet the impact of operation in a marine environment with a wave height of 6 meters.
3) TD of offshore container is lower than -20°,therefore, the impact requirements for steel plates of different thicknesses are as follows
t≤12mm,Impact temperature TD +10
12mm＜t≤t25mm,Impact temperature TD
25mm＜t,Impact temperature TD -20
4) When the total weight is more than 1 ton, the thickness of the main structure outside the corner column and the bottom beam must be not less than 6 mm, and the other main structure must be not less than 4 mm. (The main structure refers to the structure that transmits the load to the hook, including at least the top and bottom side beams, the top and bottom end beams, the corner posts, the lifting lugs and other structures deemed necessary).
5) The thickness of the metal plate of the secondary structure is not less than 2 mm. (Secondary structure refers to structures that are not used to design the calculated strength and stiffness, including doors, walls, roofs, stiffeners, waves, internal bolting points, and tank protection structures.)
6) Special test requirements:
a) The air bag test at both ends was 0.6P.
b) 4 lifting ears, internal load is 2.5R-T.
c) 2 lifting ears, internal load is 1.5R-T.
d) Vertical impact test, the internal load is 1.0P, the cabinet is inclined by 5 degrees, but the highest and lowest points are not more than 400mm, and the bottom can be padded with no more than 50mm thick. Operation Method 1 (drop method): Quickly release from a position at least 50 mm high (the end of 50 mm height may be the weak end). Operation method 2 (down method): The constant speed of the drop is not less than 1.5 m/s.
7) The material of each part on the main structure must be traceable
8) The welding process of the main structure must be certified in accordance with the requirements of ISO15624. The sample used as the welding process must be bent, stretched, -10 degree impact, weld bead hardness test and bead X-ray film inspection, bead magnetic particle inspection and bead macroscopic metallographic inspection
9) Welders who weld the main structure must be certified in accordance with EN287-1. Welders' weld samples must be bent and inspected by bead X-ray film.
10) The main structure of the weld bead shall pass 100% magnetic particle inspection or dye inspection (satisfying the requirements of Class 1 standard). If possible, 20% of the weld bead shall be subjected to ultrasonic inspection (satisfying the requirements of Class 2 standard) (the minimum thickness of detection is 8mm) 10% of the weld bead shall be inspected by X-ray film (satisfying the requirements of Class 1 standard), and 100% of the lifting ear shall be subjected to ultrasonic inspection (to meet the requirements of Class 2 standard).