Cov ntawv thov ntawm semi -}} kua dej ntim tshuab

Semi -}}} Cov tshuab ntim tau zoo li cas los ntawm kev lag luam, kev siv tshuaj, tshwj xeeb yog cov khoom noj khoom haus, thiab tshuaj ntsuab} meterical metering thiab filling filling. Piv txwv li, cov kua ntxwv thiab cov khoom noj kom haum rau hauv kev lag luam khoom noj khoom haus, thiab cov tshuaj pleev ua kom txhua tus tau ntim hauv lub tshuab tshuaj, txhua yam siv rau kev siv hluav taws xob, tuaj yeem siv cov tshuab ua kua.