I would check if the system is stable if the nozzle is disconnected.

A positive load may mean that your last support before the nozzle is functioning as a pivot point and if the nozzle is disconnected the pipe will displace upwards sometimes signifcantly. If the Nozzle Load is positive Y in the sustained case then I would say that it is poorly desinged. If it is only positive in the operating cases then it may not be optimally designed but it may be adequately designed.