A gate or ball type valve can be used or the isolation valve can be installed further upstream. 可以采用闸阀或球阀，或者可以将隔离阀安装在更上游的地方。
A butterfly isolation valve cannot be installed directly to the valve inlet flange, as the disc will contact the orifice plate. 蝶阀隔离阀不能够直接安装在阀门进口法兰上，因为其阀瓣将会接触到节流板。
Where piping being tested extends beyond the process unit limit without flanges, it shall be tested to the first block valve or set of flanges outside the unit limits. 如果试压管道超出了工艺装置界区而没有法兰时，则应试压至装置界区外的第一个隔断阀或第一组法兰。
