Bellow Sealing Performance
Sealing performance refers to a component's ability to remain leak-free under a specific pressure differential between its interior and exterior. During operation, bellows-type components contain a gaseous or liquid medium under pressure; therefore, maintaining a proper seal is essential. Methods for testing sealing performance include pneumatic pressure testing, leakage testing, hydrostatic (liquid) pressure testing, as well as testing using soapy water or a helium mass spectrometer leak detector.
Natural Frequency
Elastic components used in industrial applications are often subjected to varying degrees of vibration; in some cases, they serve as vibration-isolation elements and are inherently exposed to vibrational environments. For elastic components used under such specialized conditions, it is critical to ensure that their natural frequency (particularly the fundamental frequency) does not align with the frequency of any vibration source within the system, thereby preventing resonance-induced damage. Bellows-type components are widely utilized across various fields; to avoid damage caused by resonance, the natural frequency of a bellows should either be lower than the system's operating vibration frequency or at least 50% higher than it.
Operating Temperature
Metal bellows-type components operate across a broad temperature range, which is typically specified during the design and manufacturing phase. Certain specialized bellows are designed to contain liquid oxygen (-196°C) or even colder media, such as liquid nitrogen, while withstanding pressures of up to 25 MPa. Large-scale bellows expansion joints used in piping systems-sometimes with a nominal diameter exceeding 1 meter-are required to withstand pressures of 4 MPa and temperatures of 400°C, while also offering a degree of corrosion resistance. The temperature adaptability of an elastic component is determined by the thermal properties of the material used. Consequently, selecting an elastic material with appropriate thermal characteristics-based on the component's intended operating temperature range-is a prerequisite for manufacturing high-quality bellows-type components.