2、 Attention shall be paid to:
1. Confirm the geographical location for installing the pneumatic ball valve: when there is water or moisture on the ground, change the installation location or remove the water or moisture completely to ensure that the site does not sink, and the foundation must be firmly pressed. At this time, adjust the pipe to a level position with the ground.
2. One end of the pipe shall be fixed to the welding machine first, and then the packing of the pneumatic ball valve shall be opened, and one end of the pneumatic ball valve shall be fixed. If the fixed length of the butt welding machine is not enough to fix the pneumatic ball valve, two fixed machines shall be used to fix it. The other end of the pneumatic ball valve shall be adjusted to the same height as the fixed machine. The fixed surface processing heating plate is installed with pressure welding heating to maintain the separation of the joint cooling welding machine.
3. The pipe at the other end shall be welded according to the welding method after being fixed.

It is reported that the earthquakes of M4.2 and M3.3 (39.7 degrees north latitude and 118.8 degrees east longitude) occurred at 18:10 and 18:23 on September 14, 2015 in Changli County, Qinhuangdao City, Hebei Province, with focal depths of 14 km and 13 km respectively. At present, no report on casualties and wealth loss has been received.