1. The sealing surfaces of metal gaskets and flanges should be cleaned, and there should be no scratches, spots or other defects affecting the sealing performance of the connection.

2. The outer diameter of the metal seal gasket should be smaller than that of the flange seal surface, the inner diameter of the seal gasket should be slightly larger than that of the pipeline, and the difference between the two inner diameters should generally be twice the thickness of the seal gasket to ensure that the inner edge of the seal gasket does not extend into the container or pipeline after compression, so as not to hinder the flow of fluid in the container or pipeline.

3. The pre-tightening force of the metal gasket should not exceed the design stipulation, so as to avoid excessive compression and loss of resilience of the gasket.

4, when sealing gaskets are pressed, torque wrench is best used. For large bolts and high strength bolts, it is better to use hydraulic tighten. The tightening torque should be calculated according to the given gasket pressure, and the hydraulic pressure of the tightener should also be determined by calculation.

5, when installing metal gaskets, the nuts should be tightened sequentially. However, the design value should not be screwed at one time. Generally, it should be circulated at least 2~3 times, so that the stress distribution of the gasket is uniform.

6. For pressure vessels and pipes with flammable and explosive media, safety tools should be used when replacing metal sealing gaskets, so as to avoid sparks caused by the collision between the tools and flanges or bolts, resulting in fire or explosion accidents.

7. If there is leakage in the pipeline, it must be replaced or adjusted after pressure reduction treatment to install metal sealing gaskets, strictly prohibit pressurized operation.