Npauj npaim valve, tseem hu ua nrov plig plawg valve, yog ib tug regulating valve nrog cov qauv yooj yim, uas yuav siv tau rau switching tswj ntawm nruab nrab nyob rau hauv tsawg-pressure pipeline. Npauj npaim valve yog hais txog lub valve uas nws kaw (valve disc los yog npauj npaim phaj) yog lub disc thiab tig ib ncig ntawm lub valve ncej kom qhib thiab kaw.