For ease of installation, insert all flange bolts through the valve flange and then through the sleeve flange, but do not let the bolts extend beyond the surface of the flange rubber (See Figure 4).

• 为了使安装容易些，可以将所有法兰螺栓穿过阀门法兰，然后穿过套管法兰，但是不要让螺栓超过法兰橡胶表面（参阅图4）。