常見例句

• 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，特別是那些用于氨和胺設(shè)施的扳手型閥門的襯墊螺母帶有加工進(jìn)平面的凹槽。
返回 packing nut