NOTE: Twin Disc Check Valves can be installed horizontally or in the vertical position with flow up.
注意：双阀瓣止回阀能够安装在水平或流向朝上的垂直位置。
2
This paper introduces the observation, records, calculation and data check of twin turning point method, its advantages, disadvantages, points for attention are discussed.
在困难地区进行支水准路线测量时，可以采用双转点法。
3
Clerk: Oh, just a minute please, Mrs. Jones. Let me check it for you. Yes, we have your reservation. A single with shower and a double with twin beds for three days, Is that right?