Hauv kev tsim kho tshuab, kev sib txuas thiab kev txhawb nqa yog qhov tseem ceeb rau kev ua kom ruaj khov thiab ua haujlwm tau zoo. Cov ntsia hlau (tseem hu ua gaskets) yog cov khoom sib txuas. Txawm hais tias me me, lawv ua lub luag haujlwm tseem ceeb hauv kev sib dhos tshuab. Tsab xov xwm no yuav tshawb nrhiav qhov tseem ceeb ntawm cov ntsia hlau, tshuaj xyuas lawv cov haujlwm, hom, thiab qhov tseem ceeb hauv kev siv.