Temperature Stress Factors For Determining Tubing Pressure Ratings at Elevated Temperatures - Table 5 Temperature Stress Factors Temperature Stainless Steel CarbonSteel Copper Monel®400 °F °C 304SS 316SS 100 38 1.00 1.00 1.00 1.00 1.00 200 93 1.00 1.00 .96 .80 .88 300 149 1.00 1.00 .90 .78 .82 400 200 .94 .97 .86 .50 .79 500 260 .88 .90 .82 n/a .79 600 316 .82 .85 .77 n/a .79 700 371 .80 .82 .73 n/a .79 800 427 .76* .80* .59 n/a .76 900 482 .73* .78* .41 n/a .43 1000 538 .69* .73* .16 n/a n/a 1200 649 .30* .37* n/a n/a n/a * The precipitation of chromium carbides potentially resulting in intergranular corrosion may occur when exposed to operating temperatures above 800°F. Consult the factory for further information. Instructions To determine maximum allowable working pressures for tubing at elevated temperatures, multiply the applicable tube’s maximum allowable working pressure from Table 1-4 by the corresponding temperature stress factor from Table 5. Duolok tube fittings function reliably in applications ranging from cryogenic temperatures to high temperature bake out with the tube fitting material as the limiting factor. It is important to note that elevated temperatures will reduce the maximum working pressure capability of the tubing system. (For more information regarding the effects of temperature on tubing pressure ratings, refer to Table 5 regarding temperature stress factors in SSP’s Selection Guide for Instrumentation Fittings and Tubing).