Performance and selection of bellows——HERO VALVE

Basic properties of bellows: The materials suitable for bellows production must have good plasticity, high elasticity, tensile strength and fatigue strength, stable elasticity and good welding performance. Austenitic stainless steel is widely used to manufacture bellows due to its performance characteristics.

High pressure resistance: Pressure resistance is the basic requirement of valves and bellows. However, as the pressure level of the valve increases, the wall thickness and rigidity of the bellows increase, which makes valve opening and bellows manufacturing more difficult. Bellows manufacturers usually do not simply increase the wall thickness, but increase the number of layers to improve the pressure resistance of the product, while reducing the axial rigidity of the bellows and reducing the opening force of the valve. The wall thickness of austenitic stainless steel bellows with a nominal pressure of less than 15 MPa (900 lbs) generally ranges from 1 to 6 layers. The bellows under this pressure level have a certain versatility and have formed a series of products.

If the performance parameters of the bellows cannot meet the technical requirements, the geometric parameters of the bellows should be modified appropriately. Bellows have different uses and different technical requirements. The corresponding design method should be formulated according to different requirements during design. The main requirements for measuring bellows are usually stiffness, strength and elastic properties. Although various bellows with different geometric shapes and size parameters can meet the same stiffness requirements, the stress values generated in these bellows are different. It is reasonable to meet the requirements of stiffness and generate less stress in the work. The reduction of stress not only improves the safety factor, but also reduces the influence of material elasticity on hysteresis, aftereffect, fatigue, etc. Thereby improving the accuracy and working reliability of the bellows.

——CHINA · HERO VALVE