摘要 |
A sealing arrangement for a valve or shaft is disclosed which is designed to respond to movements of a rotatable element in a particular manner and to increase sealing pressure with increasing fluid pressure. The seal undergoes a radial compressive type movement as the pressure within a vessel housing increases between opposed sealing sleeves and this causes an increase in the sealing pressure. This predetermined movement of the seal creates a spring bias in the seal, urging the seal to return to the original, less stressed condition. Preferably, the seal is of a composite structure and a particular component of the intermediate wall section creates this spring bias. This structure has improved operating characteristics and accommodates a wider range of resilient materials to be used for the sealing washer.
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