Welded aluminum sheathed cable has become the mainstream of high-voltage cross-linked cable metal sheath

"Welded aluminum sleeve cable has become the mainstream of high-voltage cross-linked cable metal sleeve," recently, some experts introduced, China's power department has been choosing the order of metal sleeve is extruded lead sleeve - extruded aluminum sleeve - welded aluminum sleeve - aluminum-plastic comprehensive sleeve
.
In the choice of land cable metal sleeves, welded aluminum sleeves have been discriminated against, while extruded aluminum sleeves are popular, forcing some cable manufacturers to import second-hand aluminum presses
at all costs.
Due to the continuous improvement of domestic aluminum sleeve welding and rolling equipment, continuous improvement of detection methods and continuous progress of auxiliary water-blocking materials, the quality of welded aluminum sleeve and the overall waterproof sealing of the cable are greatly improved, and the welded aluminum sleeve cable is more and more accepted by users
.

Experts said that high-voltage cross-linked cable metal sheath equipment has a long
history of development abroad.
From 1797, the lead sleeve of the cable was made by the extrusion method, and until 1900, almost all large cable factories in the world used piston extruders to manufacture lead sheathed cable
.
However, due to the small mechanical strength and high weight of the lead sleeve, lead alloy
was later used.
However, lead and lead alloy sleeves recrystallize when the cable is subjected to vibration, repeated bending and thermal cycling, resulting in micro-cracks and reduced water resistance
.
The aluminum sleeve includes three types: extruded type (including pressed aluminum and extruded aluminum), welded type and composite aluminum strip type, of which land cables are most widely used in welding corrugated type
.
Due to the poor corrosion resistance of aluminum, aluminum sleeves are no longer recommended for submarine cables
.
The composite aluminum strip comprehensive cladding was first developed and used
by France.
The thickness of the aluminum strip is 0.
1-0.
3mm, single-sided coated with polyethylene copolymer, longitudinally wrapped on the cable core and bonded with a cover
.

It is understood that so far, in addition to using lead sleeves on some 400k and 500kV cables, Europe has basically abandoned the traditional vertical aluminum press and used a large number of welding equipment
。 Although some cable companies in Europe and the United States, such as the Southern Wire Company of the United States, De ABB, French Silec (Silec) and Nexans (Nexans) and other high-voltage cross-linked cables in various forms of metal sheath: aluminum strip + copper wire, lead wrap, lead package + copper wire, smooth welded aluminum sleeve, corrugated welded aluminum sleeve, 69kV and 115kV class cables also use aluminum strip bonding comprehensive sheath, but in addition to the submarine cable using lead alloy sleeve, land cables are the most used is welded
。