what is the causes of ball valve leakage

There are many kinds of stainless steel ball valves, each of which has different uses. When choosing ball valves, we should know what kind of Ball Valves we need. Ball valve is essential, and there will be some leakage problems such as failure. Today I will tell you the reasons for the leakage of ball valve.

Causes of internal leakage
1. The casting quality of iron castings is not high, and there are sand holes, loose structures, slag inclusions and other defects on the valve body and bonnet body.
2. The bolt is loose due to thermal shock, and the pre tightening force of the bolt is not good. Or the nonuniformity of bolt is higher than that of flange.
3. The contact between gasket and flange becomes weak due to aging failure or mechanical vibration. Touch surface with low precision (with grooves, ridges, etc.) and medium
4. Poor welding, slag inclusion, no welding, stress crack and other defects
5. The cast iron valve is damaged after being hit by heavy objects.

External leakage cause
1. The packing is not selected correctly, is not resistant to medium corrosion, and is not resistant to the use of high pressure or vacuum, high temperature or low temperature of the valve.
2. The filler has aged and lost elasticity after the service life.
3. The number of packing rings is insufficient, and the gland is not pressed tightly.
4. The gland is skewed, and the gap between the gland and the valve rod is too small or too large, which causes the valve rod to wear.
5. Improper operation and excessive force