Dab tsi yog cov yam ntxwv ntawm plug li qub?1, lub cev lub cev ntawm lub ntsaws valve yog kev koom ua ke, sab saum toj-mounted tsim, qauv yooj yim, yooj yim hauv internet tu, tsis muaj valve to point, txhawb siab dua pipeline system zog.2, qhov nruab nrab hauv cov txheej txheem tshuaj muaj zog corrosive, nyob rau hauv chem ...
Nyeem ntxiv