Muab faib los ntawm cov khoom siv
Lawv tuaj yeem muab faib ua plaub pawg:
Hlau manhole npog: cam khwb cia hlau, ductile hlau, bronze manhole npog, thiab lwm yam .;
Siab-lub zog steel fiber reinforced qhob manhole npog (Cement-raws li cov ntaub ntawv sib xyaw);
Recycled resin manhole npog (Recycled resin-raws li cov ntaub ntawv sib xyaw);
Polymer{0}}raws li composite manhole npog, thiab lwm yam.
Classified los ntawm cov duab
Lawv feem ntau muab faib ua voj voog thiab square.
Hauv kev tsim kho hauv nroog, lub voj voog manhole npog feem ntau yog siv vim tias lawv tsis tshua qaij, muab kev nyab xeeb zoo dua rau cov neeg taug kev thiab tsheb.
Nyob rau hauv cov cheeb tsam nyob deb nroog thiab rau cable manholes, square manhole npog feem ntau yog siv los tiv thaiv dej nag thiab lwm yam dej los ntawm kev nkag mus.
