1)how can I update my material database of Caesar
From the Main Menu, select "\tools\Material Database Editor".

2) can we give gap between guides in Caesar ? my friend is saying its not a good practice to give gap between guides ,if we are providing gap needs to provide friction coefiecent ?
Yes you can put a gap on your restraints - that is what the "gap" box is for. Gaps are used all the time, and yes you can define friction at these locations.


3) why we are checking stress in cold modules and nozzle in hot modules ,how does it make changes in our output please explain
The failure mechanism for piping is different then the over-load conditions on nozzles (which vary by equipment type). This is a really broad question, can you be more specific?


4) hanger design case is makin with operatio case or design case? is it true if we are taking hanger design for both cases( ie w+P1+T1+H and w+P2+T2+H)
The hangers must be designed for all conditions that the piping system can experience.

5) how does frictional support work?is it practical with zero friction?
You define a "mu" value at each restraint. The friction force acting at that restraint is determined and added to the load vector for that specific load case. Friction is explained in detail in Chapter 6 of the Technical Reference Manual.