Hello Dears,
I've reviewed several the CAESAR II on-line documentation about the spring support selecting. There are somethings that I can't understand them. I've listed them below.

Cold Load Spring Hanger Design. Cold Load Spring Hanger Design is a method of designing the springs, whereby the hot (or operating) load is supported in the cold (or installed) position of the piping. This method of spring design offers several advantages over the more usual hot load design:

- Hanger stops are easier to remove.
Why?
-There is no excessive movement from the neutral position when the system is cold or when the stops are removed.
Why?
-Spring loads can be adjusted before the system is brought up to temperature.
Why?
-Some feel that the cold load approach yields a much more dependable design.
Why?
-In some system configurations, operating loads on connected equipment are lower. A typical configuration resulting in this "load-reduction" is one where a hot vertical riser, anchored at the bottom, turns horizontally into a nozzle connection. The spring to be designed is at the elbow adjacent to the nozzle. Operating loads are lower because the difference between the hot and cold loads counters the moment produced by the vertical thermal expansion from the anchor.

The disadvantages to cold load design are

-In some systems, in the hot condition the loads on rotating equipment may be increased by a value proportional to the spring rate times the travel.
Why?
-Most installations are done on a hot load design basis.
Why?

Hello dears,
Why no one didn't answer me?

Spring supports balance intended load at only one position. Sometimes this is important. Cold load design attempts to balance load while piping is cold. Sometimes this is useful.
(Simply asking "Why?" stimies response. A big request with a small commitment on you side.)