1. The wide mouth
Offset, refers to the pipe and flange is not vertical, different center, flange surface is not parallel.Flange leakage occurs when the internal medium pressure exceeds the load pressure of the gasket.This situation is mainly caused in the process of installation or maintenance, easier to be found.Such accidents can be avoided by proper inspection at the completion of the project.
2. Wrong
Offset means that the pipe is perpendicular to the flange, but the two flanges are not centered.Flange of different centers, resulting in the surrounding bolts are not free to enter the bolt hole.In the absence of other means, only reaming or a smaller bolt through the bolt hole, this method will reduce the tension of the two flanges.In addition, the sealing line of the sealing surface is also deviated, which is very easy to leak.
3. The open mouth
Open mouth, refers to flange clearance is too large.Flange clearance is too large and cause external load, such as axial or bending load, gasket will be impacted or vibration, loss of compression force, thereby gradually losing the sealing kinetic energy and lead to failure.
4. The wrong hole
Staggered hole, refers to the pipe and flange concentric, but two flange relative distance between the bolt hole deviation.Wrong hole will make the bolt stress, the force is not eliminated, will cause shear force on the bolt, a long time will cut off the bolt, resulting in seal failure.
5. Stress effect
In the flange installation, the two flanges are relatively standard butt joint, but in the system production, the pipe into the medium, resulting in pipe temperature changes, pipe expansion or deformation, so that the flange by bending load or shear force, easy to cause gasket failure.
6. Corrosion effects
The chemical change of the gasket is caused by the long time erosion of the gasket by the corrosive medium.The corrosive medium penetrates into the gasket, and the gasket begins to become soft and lose its compression force, resulting in flange leakage.
Expansion by heat and contraction by cold
Due to the thermal expansion and cold contraction of the fluid medium, the bolts expand or contract, so that the gasket will have a gap, the medium through the pressure leakage.