Cause analysis of leakage of neck flange
The neck flange will inevitably leak in the use process. The common reasons for leakage are as follows:
1, the wrong mouth, the wrong mouth is straight pipe and flange, but the two flanges are different so that the bolts around can not easily enter the bolt hole. Some will choose to reaming may be the use of small bolts, but this will reduce the tension of the flange.
2, bias, bias is the pipe and flange is not straight, and the neck flange surface is not parallel and different center. It is assumed that leakage occurs when the pressure of the internal medium exceeds the load pressure of the gasket.

3, corrosion, corrosion medium on the gasket for a long time a corrosion will cause chemical changes in the gasket, make the gasket soft, lose compression force.
4, the wrong hole, the wrong hole is better understood, is the pipe and flange concentric, but the distance between the bolt hole of the two neck flanges tends to be too large, the bolt will stress, a long time will block the bolt, causing sealing failure.