Lub flat drve yog lub valve teb nyob rau hauv cov duab ntawm qhov kaw lossis plunger. Tom qab tig 90 degrees, cov channel qhib rau ntawm lub valve ntsaws yog tib yam li lossis sib cais los ntawm cov channel qhib ntawm lub zog valve kom tiav qhib lossis kaw. Nws yog dav siv nyob rau hauv Ailfield excavation, tsheb thauj mus los thiab muab cov khoom siv hluav taws xob, thiab cov li qub yog xav tau hauv Asphalt sib tov nroj tsuag.

Lub valve ntsaws ntawm lub ntsaws valve rau hauv asphalt sib tov cog tuaj yeem yog cylindrical lossis conical. Hauv cov cylindrical valve plug, cov channel feem ntau cov duab sib dhos; Nyob rau hauv conical valve plug, cov channel yog trapezoidal. Cov duab no ua rau cov qauv ntawm lub teeb ntsaws valve lub teeb thiab haum rau thaiv thiab txuas xov thiab kev sib txawv.
Txij li thaum lub zog ntawm cov chaw sib khi ntawm cov ntsaws valve muaj cov nyhuv ntsaws, thiab thaum qhib qhov nruab nrab, yog li nws tuaj yeem siv rau kev tshaj tawm nrog cov lus raug tshem tawm. Tsis tas li ntawd, lwm qhov tseem ceeb ntawm lub ntsaws valve yog tias nws yooj yim hloov kho cov qauv roj av, uas tuaj yeem muab cov roj sib txawv thiab qee qhov txuas cov khoom siv uas yuav tsum tau ua hauv cov khoom siv.
Lub ntsaws valve ntawm asphalt sib tov cov nroj tsuag yog haum rau kev ua haujlwm nquag vim tias nws tau qhib sai thiab yooj yim thiab kaw. Nws tseem muaj qhov zoo ntawm cov kua me me, cov qauv me me, kev ua haujlwm me me, kev ua haujlwm yooj yim, tsis muaj suab nrov.
Thaum cov ntsaws lub valve yog siv rau hauv asphalt sib tov nroj tsuag, nws yuav tsis raug txwv los ntawm cov khoom siv tau yog ib qho, uas ntxiv txhawb nws cov cuab yeej siv. Qhov tseeb, ntxiv rau cov kev hais dhau los saum toj no, cov ntsaws lub valve tseem tuaj yeem siv dav hauv petrochemical, tshuaj ntsuab, roj av roj av thiab kev lag luam dav.