Nyob rau hauv kev coj ua welding, lub vuam nto yuav tsum tau npaj los xyuas kom meej qhov zoo tshaj plaws weld ua tau. Kev npaj yog xav tau rau txhua hom kev vuam thiab txhua hom pob qij txha. Feem ntau, pob tw welds xav tau kev npaj me me, tab sis qee qhov tseem xav tau rau qhov zoo tshaj plaws. Phaj npoo tuaj yeem npaj rau pob qij txha hauv ntau txoj hauv kev, tab sis tsib txoj kev siv ntau tshaj plaws yog oxyacetylene txiav (oxy-roj vuam thiab txiav), machining, chipping, sib tsoo, thiab cua carbon-arc txiav los yog gouging. Txhua txheej txheem muaj qhov tshwj xeeb zoo rau lawv siv.
Rau cov khoom siv hlau, oxyacetylene txiav yog hom kev npaj ntau tshaj plaws. Cov txheej txheem no muaj txiaj ntsig zoo vim nws qhov nrawm, tus nqi qis, thiab yoog raws. Machining yog qhov ua tau zoo tshaj plaws rau kev tsim khoom thiab kev tsim khoom ntau ntawm cov khoom. Kev npaj ntawm J lossis U pob qij txha yog ib qho kev npaj los ntawm kev siv tshuab vim qhov xav tau kom raug siab. Txoj kev chipping yog siv los npaj cov khoom uas tau tsim los ntawm casting. Kev siv kev sib tsoo los npaj cov khoom yog tshwj tseg rau cov ntu me me uas tsis tuaj yeem npaj los ntawm lwm txoj kev. Cua carbon arc txiav yog muaj nyob rau hauv kev lag luam uas ua hauj lwm nrog stainless hlau, cam khwb cia hlau, los yog zoo tib yam carbon hlau.
Ua ntej vuam cov ntaub ntawv sib txawv, ib lossis ob lub ntsej muag ntawm qhov zawj tuaj yeem ua tau buttered. Cov txheej buttered tuaj yeem ua tau zoo ib yam li cov hlau muab tub lim lossis cov hlau sib txawv uas yuav ua raws li qhov tsis sib xws ntawm ob lub hlau yuav tsum tau koom nrog.
