Hi Kevin,

From the model my assumption is that the reason of increase in the moment in X-direction will be the arrengment you have between node number 64 to 130.
The distance is not clear from the graphics. Can you attached one more copy with the distance mention clearly? The arrengment looks so stiff that there is no any pipe piece to take care of the movement due to thermal expansion near the nozzle . attach the distance also.

Regards,
RK