I modelled a piping system recently in CAESAR II. Now when I carried out the static analysis run, I discovered that the system did not satisfy Code compliance when I used guides but when I changed the guides to +Y restraints, the Piping system passed the Code check. Please why was that the case? As a fallout of this I need explaination/interpretation of the various restraints nomenclature.

Regards

Progressing Pipe stress Engineer

Your original Y restaint was a "+/-Y". The +Y allowed the support to lift off thus reducing the displacement stresses.

Interpretation of the sustained stresses in this situation is another story where opinions differ. Have a look at the other posts on lifting off supports.

Amachree,

Guides are lateral restraints. If you specified just a guide, there was no vertical restraint.

Limit stops (or bumpers or directional anchors) are axial restraints. Again, no vertical restraint.

Y restraints are vertcial restraints (assuming you are not using the Z-axis vertical convention).

Typically, you will need a Y (or +Y) restraint with any guide or limit stop.

Hope this helps.

1) You should have used the [New Topic] button instead of the [Post a Poll] button. This is not a poll, it is a question.

2) Chapter 3 of the Applicaton's Guide explains the restraints, terminology, and direction.

Amachree,

I know this could be too late but in case I need jut to share my opinion. though I did not see your layout, I can realize that your pipeline failed in a guide simply becuase it did not have sufficient flexibility to expand horizontally. A guide restarint the pipe to move horizonatally. On some cases, try giving a gap to your guide starting from small figure like 1/16" to a higher one (even 3" or more if it works) and if the stresses pass that's the right guide for you. In your case, the system pass when you chaneg it to a +Y simply because +Y restaint the pipe only from going down - meaning it is simply a vertical support and it is free to go up. Technically, since you came from a guide, I would assume you use a +Y and an X or Z either with gap or without a gap. You could still have a guide without a vertical support but I would only assume you have a vertical support. So when you change it only +Y (maybe you have only removed the X or Z as your guide leaving the +Y), your line pass the code check because you have let the pipe expand horizontally. This is not a general rule. The concept is, study the piping flexibility and how to retraint them so to contain stresses and overloading on supports. Just keep on studying and make some trials on Caesar if you can.

Ed-Lamigo