mankhwala athu waukulu ndi mkulu-pafupipafupi molunjika msoko mipope zitsulo ndi mbali ziwiri kumizidwa arc welded mipope zitsulo, etc., amene ankagwiritsa ntchito sing'anga ndi otsika kuthamanga madzimadzi kufala mapaipi monga mafuta, gasi, madzi, nthunzi, mpweya, etc., komanso structural zitsulo mapaipi kwa pil...
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