Ua ntej, dab tsi yog qhov kev nyab xeeb valve Lub tub yees kev nyab xeeb valve yog ib hom valve siv los tiv thaiv cov khoom siv tub yees thiab kev ruaj ntseg system, belongs rau lub siab tsis siv neeg nyem valve. Kev nyab xeeb valve feem ntau yog tsim los ntawm lub cev lub cev, lub valve npog, lub caij nplooj ntoos hlav, spool thiab cov lus qhia. Nws qhib thiab kaw ...
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