Cov Khoom Taw Qhia Ua los ntawm cov hlau tsis zoo, cov couplings no muaj qhov tshwj xeeb ruaj khov, tiv taus corrosion, thiab lub neej ntev, ua rau lawv tsim nyog siv rau hauv kev xav tau ib puag ncig xws li cov chaw ua tshuaj, roj av refineries, khoom noj thiab dej haus ...
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