V-hom pob valve yog lub pob valve ruaj khov thiab ib lub rooj sib khi pob valve. Nws txoj kev tswj hwm kev ua tau zoo yog qhov zoo tshaj plaws ntawm cov pob li qub. Cov yam ntxwv ntws yog sib npaug feem pua, thiab qhov kev hloov pauv tau nce mus txog 100: 1.
