短語詞組短語flapper -valve 板閥flapper seal valve 密封瓣閥flapper actuator valve 瓣閥Nozzle Flapper Servo Valve 噴嘴擋板伺服閥Nozzle flapper valve 噴嘴兒擋板閥bulkhead flapper valve 艙壁瓣閥flapper type exhaust valve 舌門型排氣閥jet flapper valve 單噴嘴擋板閥 返回 flapper valve