Thaum xaiv ib lub manhole npog, ib qho ncaj lifting manhole npog feem ntau pom zoo. Hom manhole no feem ntau muaj cov seem cylindrical, flange, flange phaj, thiab viav caj npab.
Txhawm rau qhib lub hau npog, nws yuav tsum tau tig tawm sab nraud ntawm ib lub kaum ntse ntse; kaw nws, nws yog flipped inwards. Txawm li cas los xij, cov qauv no muaj qee qhov tsis zoo: nws tsis yooj yim rau kev khiav lag luam, muaj tus nqi siab dua, nyuaj rau kev sib sau ua ke, thiab muaj kev ua haujlwm qis dua.
Hauv kev sib piv, rotary- pub ceev- qhib manhole npog thiab atmospheric siab manholes yog yooj yim rau kev khiav lag luam, tab sis tej zaum yuav tsis haum raws li tej yam kev mob. Qhov kev xaiv tsim nyog tshaj plaws rau lub hau npog yuav tsum tau txiav txim siab raws li qhov xav tau tiag tiag thiab qhov xwm txheej tshwj xeeb.
