Ngophuhliso loluntu, ilizwe linika ingqwalasela ngakumbi nangakumbi kulwakhiwo lwemicimbi kamasipala. Ngoko ke, njengesixhobo esibalulekileyo ekuphuhliseni nasekwakhiweni kwemicimbi kamasipala, izityalo zokuxuba i-asphalt ziya zithandwa kakhulu kwaye ukusetyenziswa rhoqo kuyanda. Izityalo zokuxuba i-asphalt ziya kudibana nezinye iimpazamo ngaphezulu okanye ngaphantsi ngexesha lokusetyenziswa. Eli nqaku libonisa ngokufutshane indlela yokusombulula impazamo yevalve yokubuyisela umva kwisityalo sokuxuba i-asphalt.

Ukuba kukho ingxaki nge-valve yokubuyisela kwisityalo sokuxuba i-asphalt, ukubonakaliswa ikakhulu kukuba i-valve ayikwazi ukuguqulwa okanye isenzo sokubuyisela sihamba ngokukhawuleza. Kusenokubakho ukuvuza kwerhasi, ukungaphumeleli kwevalvu ye-electromagnetic pilot, njl. Ngokuqhelekileyo, xa udibana nengxaki enjalo, into yokuqala ekufuneka uyiqwalasele kukufumana unobangela wempazamo, ukuze isiphene sipheliswe ngokuchanekileyo nangempumelelo.
Ukuba ivalve yokubuyisela umva ayinakubuya umva okanye isenzo sokubuyisela umva sicotha noko, umsebenzisi unokuthathela ingqalelo izizathu ezinjengokuthanjiswa okulambathayo, i-spring jamming, okanye ukungcola kwe-oyile okuxinanisela iindawo ezityibilikayo. Ngeli xesha, umsebenzisi unokuqala ukujonga isixhobo se-oyile ye-oyile ukujonga imeko yokusebenza, kwaye emva koko uqinisekise i-viscosity yeoli yokuthambisa. Ukuba ingxaki ifunyenwe okanye iyimfuneko, ioli yokuthambisa okanye i-spring ingatshintshwa.
Ukuvuza kwegesi ngokuqhelekileyo kubangelwa i-valve yokuguqula isityalo sokuxuba i-asphalt esebenza kwi-frequency ephezulu ixesha elide, elibangela ukuguga kwe-valve core seal ring kunye nezinye iindawo. Ukuba itywina aliqinile, ukuvuza kwegesi kuya kwenzeka ngokwemvelo. Ngeli xesha, i-ring yetywina okanye i-valve stem kunye nezinye iindawo kufuneka zitshintshwe.