What are the characteristics of welded metal bellows seals?
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The bellows used in mechanical seals for welded metal bellows are formed by cutting rolled metal sheets into an annular corrugated shape; the wave pattern is usually S-shaped. Multiple such wave plates are stacked together and welded at both the outer and inner edges of the ring to create a single bellows, which is then welded to the drive seat and the moving ring to form a unified unit. In addition to not requiring an auxiliary sealing ring, it also features a wide operating temperature range, ranging from up to 600°C to as low as -200°C. Furthermore, it has strong adaptability to shaft vibration and oscillation at high speeds, offering excellent compensation capabilities to ensure proper sealing of the end faces. However, in welding metal bellows seals that operate under high temperatures for extended periods, the elasticity of the bellows tends to decrease (commonly known as \"loss of elasticity\"), which imposes certain limitations on their use.
The advantages of welded metal bellows seals include a wide operating temperature range (from -200°C to 600°C), no need for additional sealing rings, strong tolerance to shaft vibration and deflection, and excellent compensation capabilities that ensure proper fitting of the sealing surfaces. However, long-term use at high temperatures may lead to a decrease in the elasticity of the bellows. .