1、 Confirm the preparation before installation of pneumatic ball valve: ensure that the installation position of pneumatic ball valve is on the same axis, the two flanges on the pipeline should be kept parallel, and confirm that the pipeline can bear the weight of the ball valve itself. If it is found that the pipeline cannot bear the weight of the ball valve, provide corresponding support for the pipeline before installation
Confirm whether there are impurities, welding slag, etc. in the pipeline, and purge the pipeline.
Check the nameplate of the pneumatic ball valve, operate the pneumatic ball valve fully open and fully closed for several times, confirm that the valve can work normally, and then check all details of the valve comprehensively to ensure that the valve is intact.
Remove the protective covers at both ends of the pneumatic valve, check whether the inside of the valve body is clean, and clean the inner cavity of the valve body. Since the sealing surface of the pneumatic valve is spherical, even small sundries may cause damage to the sealing surface.

Leakage control technology and knowledge summary of non-metallic compensator
（1） Overview
In order to ensure the characteristics of large temperature variation, strong corrosiveness and irregular shrinkage of the desulfurization flue, non-metallic shrinkage joints are used in the selection of shrinkage joints. The non-metallic shrinkage joints are easy to manufacture, easy to construct on site and extremely low in cost. The non-metallic contraction joint is composed of skeleton and skin. The skeleton is made of 20 # channel steel, and the skin is composed of four to ten layers of fabric, which is then fixed on the channel steel with pressure plates and screws.
（2） Analysis of the cause of leakage
(1) Leakage caused by design defects