Hi

I have query in equipment modeling.

Some of the equipment directly welding to steel in plant and some equipment's Bolted to the steel.
My doubt is in CAESAR II modeling we need consider anchor for both bolted condition & welded condition

or

For bolted condition only need to fix 3 degrees of freedom(X,Y,Z) and rotation should be free. As this concept is correct?

Depends. If the bolted connections are cinched, then it's effectively anchored. If the bolted connections are double-nut counter-screwed, then it's possible you have some degrees of freedom. However, the more bolts you have at one location, the fewer degrees of freedom you have.

You have to make the decision whether or not those degrees of freedom are meaningful to the analysis to merit taking the time to model each of them.