The temperature derating factor to be used in the design formula in §192.105 is determined as follows:
Gas Temperature in degrees Fahrenheit (Celsius) |
Temperature derating factor (T) |
250ºF (121ºC) or less |
1.000 |
300ºF (149ºC) |
0.967 |
350ºF (177ºC) |
0.933 |
400ºF (204ºC) |
0.900 |
450ºF (232ºC) |
0.867 |
For intermediate gas temperatures, the derating factor is determined by interpolation.
[35 FR 13257, Aug. 19, 1970, as amended by Amdt. 192-85, 63 FR 37502, July 13, 1998]