Raju,

The spring hanger in and of itself is not the cause of your non-convergence. Non-convergence is ALWAYS caused by nonlinear boundary conditions such as uni-directional restraints, friction, or large-rotation rods. Having said that, changing a hanger location will change the load distribution in the piping system such that a nonlinear boundary condition elsewhere in the model is affected.

In a nutshell, nonlinear boundary conditions require Caesar to alter the boundary condition between iterations. Sometimes it gets stuck in an infinite loop because it changes the boundary condition back and forth on successive iterations. Of course this situation is exacerbated by large numbers of nonlinear boundary conditions. Sometimes as innocuous a change as a 5 degree temperature increase will make a previously converging model become non-convergent. This is simply the nature of the numerical methods employed and does not reflect in any way on the design of the piping system.