輸入需要查詢的關鍵字：
詞語：flop-valve
flop-valve的意思
flop-valve 瓣閥;clack valve flap valve flop-valve 瓣閥;flip-flop valve 觸發器閥，啪嗒啪嗒作響的閥，突然改變方向的閥;