On gaswithdrawal systems, use a check valve or other protective apparatus in any line or piping from the container to prevent reverse flow.
对于气体排出系统，使用止回阀或其它保护性装置以防止回流。
2
Cylinders can be supplied with standard valves for gaswithdrawal or with siphon tubes connected internally to the valves for liquid withdrawal.
钢瓶可以配有用于气体提取的标准阀门或在内部连接到阀门的用于液体提取的虹吸管。
3
Societe generale's analysis suggests that a full withdrawal from nuclear by OECD countries would increase demand for gas by more than 400 billion cubic metres a year by 2045.