The double-layer structure of the metal expansion joint is designed to ensure its pressure resistance performance in various ways, and the specific measures include but are not limited to the following aspects:
Material selection：
High strength material: Inner and outer corrugated pipes are usually made of alloy materials with high strength and good ductility, such as stainless steel. These materials are not only able to withstand high internal pressures, but also adapt to thermal expansion and contraction due to temperature changes.
Corrosion resistance: Selection of materials with good corrosion resistance can prevent material deterioration due to media attack, thereby maintaining the overall strength of the structure.
Bellows Design Optimization：
Corrugation shape and size: Reasonable design of corrugated height, spacing and other parameters can increase the wall thickness of corrugated pipe or adopt multi-layer corrugated structure without sacrificing flexibility, so as to improve the overall pressure resistance.
Increased number of layersThe double-layer structure itself means that it provides higher pressure resistance at the same material thickness compared to the single-layer design. With each additional layer, it is equivalent to adding an additional pressure barrier.
Reinforcing ring and supporting structure：
In some designs, reinforcing rings or other forms of support structures are added inside or outside the bellows, which can not only limit the maximum deformation of the bellows and reduce stress concentration points, but also effectively disperse the pressure load and enhance the overall pressure resistance.
Welding quality control：
For the connection parts in the double-layer structure (such as the welding joints between the inner and outer layers), it is necessary to ensure the high quality completion of the welding process, so as to avoid the appearance of welding defects (such as pores and cracks) that affect the structural integrity and pressure resistance.
Rigorous testing and verification：
During the production process, a series of tests will be carried out on the finished product, including hydraulic pressure test, air tightness test, etc., to verify whether it meets the pressure resistance standard required by the design.
Evaluate the durability and reliability of products in long-term use by simulating pressure cycle tests under real working conditions.
To sum up, the double-layer structure of metal expansion joint effectively improves its pressure resistance performance through comprehensive application of material science, precision design and strict quality control measures, and ensures that it can still operate safely and reliably under complex working conditions.