Kev ua haujlwm ntawm lub rooj vag valve, lub ntiaj teb valve thiab pob valve: lub rooj vag valve tsuas yog qhib thiab kaw tag nrho, thiab tsis tuaj yeem hloov kho thiab throttled. Globe valve tuaj yeem siv los txiav tawm lossis throttling. Lub pob valve feem ntau yog siv los txiav tawm kev faib tawm thiab hloov cov kev taw qhia ntws ntawm qhov nruab nrab hauv cov kav dej. Nws tsuas yog yuav tsum tau tig 90 degrees thiab lub zog me me tuaj yeem kaw nruj nreem. Lub pob valve yog qhov tsim nyog tshaj plaws rau kev siv los ntawm kev kaw-off valve.
