Cov qauv siv hluav taws xob cuam tshuam nrog lub gasket rau lub qhov rooj tsis muaj suab nrov thiab hluav taws kub, uas sib xyaw ua haujlwm ntawm kev tiv thaiv hluav taws thiab lub suab rwb thaiv tsev. Ntxiv rau qhov kev ua haujlwm ntawm cov qhov rooj zoo tib yam, qhov rooj hluav taws kuj muaj cov haujlwm ntawm kev tiv thaiv kev sib kis ntawm hluav taws thiab cov pa taws, uas tuaj yeem tiv thaiv kev sib kis ntawm hluav taws hauv qee lub sijhawm thiab xyuas kom muaj kev khiav tawm ntawm tib neeg.