Valve Steel
Raws li ib qho ntawm cov tuam txhab ua lag luam thiab cov muag khoom nyob rau hauv Suav teb rau 20 xyoo, peb sov siab txais tos koj mus yuav cov khoom siv valve hauv Suav teb ntawm no los ntawm peb lub hoobkas. Tag nrho cov khoom yog nrog cov khoom zoo thiab cov nqi sib tw.