Ma welded semi-rigid centralizers ndi zida zofunika kwambiri pamakampani amafuta, ndipo mtundu wazinthu ndizofunikira kwambiri pakuwonetsetsa kuti ntchito yobowola ndi simenti ikuyenda bwino. Mwachikhalidwe, ma centralizers amapangidwa ndi zitsulo zamtengo wapatali, zomwe zimakhala zodula. Komabe, kudzera mu uniq ...
Werengani zambiri