Colleagues,

I have a piece of equipment being supported by 2 spring cans.

By casual inspection, that piece of equipment is also being supported by a straight pipe spool that connects this piece of equipment to a second piece of equipment. However, the installers are promising to install this line such that the two nozzles only see the weight of the piping spool.

I'm then tasked with sizing the spring supports such that thermal expansions and the like do not cause nozzle issues. (I have a half dozen other nozzles I need to qualify, as well.)

Question 1: Which settings must be set in order to ensure the nozzle loads are (very nearly) 0 in the installed condition? Thinking out loud - would it be correct to state that creating an "operating" case of WNC and ask CAESAR to design "free restraint" at the nozzle node?

Question 2: Can CAESAR automatically size the spring cans for this kind of set-up?

Thanks.

Image for reference.

It's difficult to decipher who is carrying what from your description.
Generally, yes, releasing restraints while calculating hanger loads can unload your equipment. (It looks like you have Anchors with CNodes as your equipment connections, these are teh ones to release.) But, while this action may reduce the vertical load on the nozzle, the other 5 load components lack any similar control.
You say you want zero load installed. CAESAR II assumes such a zero load would be for the operating state. To zero installed, use Cold Load Design.
You may want to run additional installed cases where you fiddle with the hangers to get the optimum loads.

In the installed condition, only the hangers are carrying any load. All nozzle loads are effectively 0.

When everything increases in temperature, loads on springs are lessened, and nozzle loads are increased.

My problem is I can't seem to figure out a load combination / hanger combination that results in 0 loads on any of the nozzles that represents an installed condition.

Thanks.

I was wondering how the installer will assure zero loads during installation.

To my understanding, it’s practically not possible that you will have no load during installation when pipes are connected.
One thing which can be tried out (non-standard solution) is;
1. Try to model the equipment with springs.
2. Do consider the three cases such as when equipment is empty, when equipment is half filled and when equipment is fully filled to design the spring.
3. The weight at these three conditions will be different. Try to design the spring as per the above three condition (optimized it).
4. Remember to check the option for the spring as designed with cold load. And create a load cases where you have locked the spring during installation (no piping is connected) and unlocking when piping is connected.

Then insert all the connected pipes to the system. (keep remember to define the spring rate and loads as you were designed for zero loads cases manually)

Run the system and check the nozzle load.

Personally I am not really found of making the restrained free. I hope this help.

Any commnets are always welcome.

Regards,
R.K.