Are there any specific advantages of selecting Lisega 205 in spring type i.e. cold design then just selecting Lisega 5, in the
input file.

The typical spring hanger design is setup to balance the system in the "operating" configuration. "Cold load design" attempts to balance the system in the cold condition.

You would need to have a "real good reason" to select "cold load design", since your system will (hopefully) be in the operating condition most of the time.

Dear Richard,

Does that mean , spring is also working even under cold conditions. But I know that generally springs act as rigid hangers in cold conditions and so kept in locked position when the line is not operating. And only when the line is operating, their spring constant comes into play.

But if I am choosing Lisega205 does tha mean I am going against the criterion mentioned by me in the above paragraph and spring becomes active even in cold conditions. Wont that result in over designing the system?

Regards
Paritosh Garg ( Siemens PG)

Once the travel stops are removed (typically and hopefully prior to the first system operation), the spring is "working"; F=K*Y. Also when the line is not in operation the travel stops are NOT reinstalled. During maintenance of the line the travel stops should be reinstalled, but one is lucky if this happens and also lucky if the field crew remembers to again remove the stops after the work is completed. Enough on this.

One advantage to using the so-called "cold design" spring option is that it MAY make the travel stops easier to remove for the field (if the line is normally vapor service) since the installed load is the actual support load. Caution: THIS SHOULD ONLY BE USED IN MODERATE TEMPERATURE SYSTEMS, e.g., <=400 F for Carbon Steel. For hot systems the standard Caesar method should be used since the actual weight shall be supported in the HOT condtion to limit sag/strain/creep and to be in code compliance.

Again personnel undertaking pipe stress analysis work should occaisionly go back to "basic principles", reference books/material, the piping code, and the CII manual to help understand the background and good practices for piping design and analysis.

Be careful out there,