Pipe rupture valve is able to close itself in the event of failure in the main cylinder line or where the down speed exceeds allowable limits in the hydraulic elevator system 限速切断阀是液压电梯中的安全保护阀，它能够在液压电梯系统出现异常情况时关闭系统，起到保护作用。
2.
Devil s advocate was a big hit and speed ii sunk at the box office . suddenly critics were saying how smart keanu was for turning down speed ii . the it was off to australia to film the matrix Keanu等演员在袁和平的要求下在开拍前特意学习了几个月的武术，因此，我们才看到了the matrix中令人惊讶的对抗和枪战场面。
