Dear,

With YROD facility in Caesar-II, isn't is justified to use in one or two instances rigid / 'user-defined' variable / constant spring hangers beyond 4 deg rotation due to some space limitations in vertical direction from the point of hanger attachment ?

With 'YROD',high stiffness & zero Fi, it is rigid hanger; with Fi as constant hanger load specified, but zero stiffness, it is constant effort spring hanger;with Fi as cold setting load & stiffness as variable spring stiffness, it is variable spring hanger.

Am I right in this approach ?

regards,

sam

Why are there no comments so far on this 4 degree topic of hangers? Caesar-II's 'YROD' gives us opportunity to go beyond '4 degree limit'.

Is '4degree' a sacred holy cow just because it originates from a MSS code of the West! What would happen, if this restriction was imposed by code of any other region who buy these products!

Please, don't take my comment seriously!

regards,

sam

the 4 degree norm is more a guideline,and to my knowledge,there is no code backing.by allowing this tilt of the hanger road from vertical,there will be a horizontal component which will act on the pipe and also a vertical movement which the hanger and pipe has to accomodate.in addition the tolerances of the hanger components need to allow this tilt.may be these are the reasons for this norm.

regards
siva131

Hi Sam,

There is a german VGB rule that gives the limit of 4 deg for the angle at a hanger. If you exceed this angle this is no big problem but the restoring forces at the hanger will rise.

I think its better if you increase the height of Hanger to compensate with the degree. Hope this will help you.

As stated above, the "small angle approximation" is not founded in any Code or Standard. Most of us have been introduced to this concept in College. The approximation assumes that rotations and deflections are small enough such that an analysis remains linear and loads and deflections remain uni-directional (so in the case of a spring hanger the load is only vertical).

You can "Google" this idea and find a wealth of information. From http://www.onlinefeasolver.com/articles/nonlinear/ you can get a quick summary.