SLEEVES ARE INSTALLED INTO OFFSHORE STRUCTURES DURING MANUFACTURE. THEY ARE TYPICALLY MADE FROM GRADE 355 EMZ AND CAN VARY IN SIZE FROM 20" TO 84" I/D. THEY CAN BE EITHER MANUFACTURED BY WELDING THICK / THIN SECTIONS TOGETHER OR THE I/D + GROOVES CAN BE MACHINED. LINERS ARE INSTALLED INTO CAISSONS ON OFFSHORE PLATFORMS. THEY ARE USED TO REPAIR + REINFORCE THE CAISSON. THEY ARE TYPICALLY MADE FROM GRADE 355 EM AND COME IN SIZES RANGING FROM 16" TO 48". TWO TYPES ARE CURRENTLY IN USE - SECTIONS WELDED TOGETHER OFFSHORE AND SECTIONS THAT ARE SCREWED TOGETHER OFFSHORE. SECTIONS TYPICALLY 3MTRS IN LENGTH. THESE ITEMS CAN BE SUPPLIED SOME MONTHS IN ADVANCE OF THE SWAGING EQUIPMENT.

CLASSIFICATION IS DETERMINED BY THE PROVISIONS OF GIRS 1 AND 6. CN CODE 73089010 STRUCTURES AND PARTS OF STRUCTURES OF STEEL OR STEEL, OTHER, WEIRS, SLUICES, LOCK-GATES,LANDING STAGES,FIXED DOCKS AND OTHER MARITIME AND WATERWAY STRUCTURES.