Dan,
The operating temperature is 31 degC and even with it the system fails with 122% overstress.
With design temperature 61 DegC system fails with 140% overstress.
Client specification also restricts me saying: Piping flexibility and stress analysis shall consider the most severe specified temperature
and coincident design pressure.
Line list design temperature is 61 degC.
Additional Information: The pipes are with threaded connection.
Regards
Zhambul