A check valve should be installed on return piping if there will be a pressurized return line or the trap drains to an overhead return line (Fig. B).
如果存在一个压力回路，或者疏水阀排放口位于回路管道的上方，则应该安装一个止回阀(图b)。
2
Therefore each line or line section shall have an expansion chamber a pressure relief valve or rupture disc discharging to a receiver.
各管路或管段应配备膨胀室，减压阀或将压力释放到储气罐的爆破隔膜。
3
The discharge line must be installed to allow complete drainage of both the relief valve and the discharge line. The discharge line must not be restricted or reduced in size under any circumstances.