Handle operated butterfly valve in the process of use may occur in the following two circumstances:
1. Leakage of sealing surface
There are three reasons for leakage of sealing surface: 1. Impurities and foreign bodies are clamped at valve plate and sealing surface.2. Valve plate and sealing surface can not be completely matched, resulting in poor sealing.3. The flange bolts at the outlet are under uneven stress, causing leakage.
2. Leakage of both ends
There are also three reasons for leakage of both ends of the valve: 1. Failure of seals on both sides, resulting in incomplete sealing or lax sealing. 2.Pipeline flange force is not uniform or not under pressure, resulting in leakage of structural connections. 3. Upper and lower sealing gaskets of sealing ring fail. Make the valve structure is not complete, resulting in leakage phenomenon.