Several Advantages of Metal Bellows Mechanical Seals

The metal bellows mechanical seal is a welding technology mainly used for the shaft seal of the hot oil pump in the refinery

The metal bellows mechanical seal has a wide range of applications, from low temperature to high temperature, from neutral medium to corrosive medium, from low speed to high speed, and from normal to harsh working conditions. There are rubber bellows and snake sleeves, plastic bellows, and metal bellows. Rubber bellows and snake sleeves are used as auxiliary seals for low-load mechanical seals, plastic bellows are used as auxiliary seals for strong corrosive medium mechanical seals, and metal bellows are used for high temperature, high pressure, and low temperature medium mechanical seals, which can be used as auxiliary seals and elastic components.

The metal bellows mechanical seal has good floating and random compensation

The metal bellows mechanical seal can compensate for leaks caused by seal ring wear, axial movement, and vibration. The welded metal bellows itself acts as an elastic element and also serves as a seal, so there is no need to design a general push-ring spring-type mechanical seal dynamic auxiliary seal ring, thereby avoiding the slight particle blocking caused by the dynamic auxiliary seal ring, The dynamic auxiliary seal is not resistant to high temperature and has the problem of reducing the sealing compensation ability due to its axial friction resistance.

There is no auxiliary sealing ring in the middle of the metal bellows mechanical seal, reducing a leakage point

The metal bellows mechanical seal reduces the friction resistance of the compensation mechanism, and improves its following ability. In the petrochemical industry, the use temperature of welded bellows seals is not limited by the auxiliary seal ring. Four fluorine bellows seals can be used in corrosive media. Its disadvantage is that some bellows have small elasticity and need to be equipped with auxiliary springs.

The metal bellows are tightly welded by each wave sheet's inner and outer diameters, so when used as a stationary or rotating, there is no need to consider the rotation problem. Welded metal bellows can be made of precipitation-hardening stainless steel, high-temperature nickel-based materials, and chromium-nickel corrosion-resistant materials, so welded metal bellows can be used in a wider temperature range, and various acids, alkalis, and salt media. Selecting different wave sheet thicknesses and layers allows it to withstand pressures up to 7 MPa in special pumps. The design of welded metal bellows mechanical seal is generally balanced, so the influence of the pressure it bears on the end face compared to the pressure is small. Welded metal bellows mechanical seals are not only suitable for non-hydrocarbon media but also suitable for flash distillation hydrocarbon media. Compared with ordinary mechanical seals, their service life has been greatly improved, so they have a higher performance-price ratio.