A na-eji ya n'ọtụtụ ụlọ ọrụ dị iche iche dị ka ụlọ ọrụ kemịkalụ, injinia electromechanical, nrụpụta igwe, nrụpụta ụgbọ mmiri, ike eletrik, petrochemical, metallurgy, plumbing, ọgwụgwọ mmiri, nrụpụta akụrụngwa akụrụngwa, pipeline pneumatic, pipeline hydraulic, wdg.