摘要 |
<p>A novel, fatigue resistant fitting of the joint ring type used between bolted, flanged sections of high pressure tubing is provided which safely and durably serves the dual functions of high pressure joint sealing and convenient instrumentation tap access. The fitting comprises two concentric, thick-walled cylindrical shells with the outer shell shrink-fitted onto the inner shell which is free of threaded portions or other stress concentration points except for one or two radial bores at about its midlength, and in axial alignment with each of said radial bores, a cleanly threaded aperture of substantially larger diameter through said outer shell. For maximum fatigue resistance under difficult service, the compound shell fitting is also subjected to an autofrettage treatment.</p> |