Socket welded or threaded flanges are not recommended outside which of the following temperature ranges if severe thermal cycling or gradients are expected?
a) -20°-300°F.
b) -50°-500°F.
c) -50°-750°F.
d) -20°-500°F.
a) -20°-300°F.
b) -50°-500°F.
c) -50°-750°F.
d) -20°-500°F.