Substation to 500kv substation frame using more LSG steel pipe, large diameter welded pipe will generally be used in caliber 299mm to 900mm but the wall thickness will certainly not be thick, generally in 6mm-14mm caliber the larger the wall thickness will be slightly thicker, the most common wall thickness of 6mm, 8mm, 10mm, 12mm, 14mm, 16mm, single these steel pipes have a lower Differential, the lower difference is generally about 0.25 in line with the national grid and some energy companies’ steel pipe pole requirements.
Substation frame straight seam steel pipe is generally selected, directly pressed into shape with steel plate (professionally called straight out without any re-heating expansion and other processes), the use of double-sided submerged arc welding to weld inside and outside, and then the weld seam grinding off. The straight seam steel pipe produced in this way can guarantee the thickness of zinc (i.e. the amount of hanging zinc can reach the requirement) and is also brighter when galvanized.
In the normal national grid standards, substation frame steel pipe is required to ensure that the chemical composition and mechanical properties of steel pipe qualified, many suppliers in order to save costs and then use hot expanded steel pipe, hot expanded steel pipe is a small diameter steel pipe heated using a mandrel using lead powder to do the lubricant expansion to the diameter we need, the chemical composition of the steel pipe in the heating process we put aside, the mechanical properties of force yield Strength Tensile strength Elongation completely does not meet the requirements of the national grid.