What is the difference between low-stress metal wound gaskets and regular metal wound gaskets?

Stress relaxation of the gasket is one of the main factors leading to leakage. The greater the stress relaxation, the lower the residual stress in the gasket. If the residual stress becomes too low to maintain the gasket’s sealing properties, leakage will occur. Metal wound gaskets are formed by alternately winding shaped metal strips and non-metallic fillers; the metal strips ensure the gasket’s resilience, while the non-metallic fillers ensure its sealing properties. They are typically used in applications with severe fluctuations in temperature and pressure. Low-stress sealing wound gaskets can achieve efficient sealing even at low bolt clamping forces. The basic design concept is the same as that of ordinary sealing wound gaskets; it simply uses thinner and fewer metal strips compared to ordinary sealing wound gaskets, while employing more filler strips. Low-stress seal winding gaskets are suitable for certain materials covered by ASME standards that are subject to constraints imposed by bolt tension. The effective sealing pressure is up to 200 Bar, **which exceeds the pressure rating of ordinary Class 150 and Class 300 flanges. Refer to ASME/ANSI standards.