常見(jiàn)例句Some wrench-operated valves, specifically those used in ammonia and amines service, have packing nuts with notches machined into the flats.一些扳手型閥門(mén)，特別是那些用於氨和胺設(shè)施的扳手型閥門(mén)的襯墊螺母帶有加工進(jìn)平麪的凹槽。 返回 packing nut