More complicated designs have been used in the past but have not had the structural integrity nor the watertight sealing capabilities of the Red Valve Hawse pipe valve.
英
美
- 以前所采用的设备则复杂得多,但是反而缺乏结构的整体性,也无法实现象美国红阀公司锚链管道阀门一样的不透水的紧密密封。