Make sure check the bolt and nut before testing run. and if they become less crowded, fastening again.
试车前务必检查所有螺栓、螺母是否有松动，若有松动的螺栓、螺母必须重新紧固。
2
Certain system configurations involving direct connection of a Swing Check Valve to other flanged equipment may require consideration of this bolt clearance.
某些系统配置，包括旋启式止回阀直接连接到其他法兰设备的场合可能要求考虑这种螺栓所需要的间隔。
3
Check the bolt and nut and filling press cover, it it become flexible during the transport or store, screw down it.