3. Leakage
3.1 The valve leaks inside and the length of the valve rod is not suitable. The valve rod of the air opening valve is too long, and the upward (or downward) distance of the valve rod is not enough, resulting in a gap between the valve core and the valve seat, which can not be fully contacted, resulting in untight closing and internal leakage. Similarly, the valve stem of the air shutoff valve is too short, resulting in a gap between the valve core and the valve seat, which cannot be fully contacted, resulting in untight closing and internal leakage. Solution: shorten (or lengthen) the valve rod of the regulating valve to make the regulating valve length suitable so that it will no longer leak inside.

In fact, the pneumatic butterfly valve has a long history of development, and it will not be introduced into China for a long time. It still needs some innovation in production technology, and domestic production enterprises can go further and further.