The expansion of liquid outlet nozzles on the pressure vessel initiates from the tangent
line of the vessel, which is situated at the junction of the bottom head of the vessel
and the skirt connection. This expansion progresses downward in direction. Consequently, it is imperative for piping stress engineers to avoid situating pipe supports
in this expansion zone. Failing to do so may lead to a conflict between the pipe support and nozzle connection, resulting
in potential overstress on the connection between the nozzle and bottom head, as well
as the piping. In operational conditions, particularly at elevated temperatures, merely relocating the
support away from the vessel is insufficient, given the extensive expansion zone of the piping
Resolving this issue may involve incorporating an expansion loop or introducing a turn from
the vessel's centerline. Furthermore, the utilization of a spring support can prove to be highly beneficial in addressing
these concerns. When making decisions, piping and stress engineers prioritize solutions that are both secure
and cost-effective. Despite the potential expenses associated with additional pipes, fittings, or spring
supports, a comprehensive study is essential to identify the most optimal solution in terms
of both safety and cost-effectiveness. This outlet nozzle is located on top of the pressure vessels
So the thermal expansion is higher that the other nozzles. In this example the piping is routed through the pipe rack
Using stopper and or guide on pipe supports is very important to reduce the forces and
moments on the nozzle. If you put a stopper to the second axle, the pipe expansion will cause excessive moment
on the nozzle. Because the pipe will expand from the stopper through the vessel and at the same time from
the vessel to pipe rack. This will cause over stress on the nozzle connection on the head of the vessel and also
over stress on various location of the pipe. This is why a piping engineer should put the stopper as close as possible to the vessel
As you can see, you can even choose a strong guide for the first support instead of a stopper
Due to the operating temperature, due to the vessels vertical expansion, the first
pipe support will not sit on the pipe rack structure. This will cause overloaded nozzle connection due to the pipe weight that will have to be
taken by the nozzle. To prevent this, piping stress engineer can use a spring support to share the pipe weight
with the nozzle