Cu-ni forged fittings feem ntau yog muab tso ua redrawn leeg hauv anealed mob. Kev sib xyaw ua ke ntawm kev ua qauv zoo thiab lub zog muab cov kev tsim nyog zoo. Ntxiv rau qhov no, cov fitting fittings tseem tiv taus xeb, oxidation, pitting, kev ntxhov siab thiab tawg kev ntxhov siab.