Hanger Table - CAESAR II - Help

CAESAR II Users Guide (2019 Service Pack 1)

Language
English
Product
CAESAR II
Search by Category
Help
CAESAR II Version
11.0 (2019)

Specifies the active hanger table.

The software provides the following hanger tables:

1. Anvil

14. BHEL

27. NHK

2. Bergen Pipe Supports Inc (formerly Bergen Power)

15. CASTIM 2000 (formerly Flexider)

28. PSSI GmbH

3. Power Piping

16. Carpenter & Paterson

29. Seonghwa

4. NPS Industries

17. Bergen Pipe Priv Ltd (India) (formerly Pipe Supports Ltd)

30. Mitsubishi

5. Lisega

18. Witzenmann

31. Yamashita

6. Fronek

19. Sarathi

32. Sanwa Tekki

7. Piping Technology

20. Myricks

33. Techno Industry

8. Capitol

21. China Power

34. Hesterberg

9. Piping Services

22. Pipe Supports USA

35. Spring Supports Mfg. Co.

10. Basic Engineers

23. Quality Pipe Supports

36. Senior

11. Inoflex

24. PiHASA

37. Unison (Korea)

12. E. Myatt & Co.

25. Binder

38. Wookwang

13. Sinopec

26. Gradior

Additional design options are available if you use the following check boxes.

  • Extended Range

  • Cold Load

  • Hot load centered (if possible)

You can globally set the hanger data for a model from the Hanger Design Control Data, accessed by clicking Hanger design criteria in the piping input. Specify the default hanger table that appears in this dialog by specifying the Default Spring Hanger Table configuration setting in Configuration Editor > Database Definitions. For examples of incorporating spring hanger designs into your models, see the Hangers section in the CAESAR II Application Guide.

Extended Load Range Springs

CAESAR II includes the maximum load range to permit the selection of less expensive variable support hangers in place of constant effort supports when the spring loads are just outside the manufacturers recommended range. Extended load ranges are the most extreme ranges on the spring load table. Some manufacturers build double-spring supports to accommodate this range. Others adjust the top or bottom travel limits to accommodate either end of the extended table. Make sure that the manufacturer can supply the spring before you use the maximum ranges. Use of the extended range often eliminates the need to go to a constant effort support.

Most manufacturers do not support an extended range. If you select Extended Range for a hanger with springs that do not support an extended range, the software returns the standard spring table and ranges.

Cold Load Spring Hanger Design

Cold load spring hanger design is a method of designing the springs in which 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.

  • There is no excessive movement from the neutral position when the system is cold or when the stops are removed.

  • Spring loads can be adjusted before the system is brought up to temperature.

  • Some feel that the cold load approach yields a much more dependable design.

  • Operating loads on connected equipment are lower in some system configurations. A hot vertical riser anchored at the bottom turning horizontally into a nozzle connection is a typical configuration resulting in this load-reduction. 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, the loads on rotating equipment may be increased by a value proportional to the spring rate times the travel in the hot condition.

  • Most installations are done on a hot load design basis.

Middle of the Table Hanger Design (Hot Load Centered)

Many designers prefer that the hot load be centered as closely as possible to the middle of the spring table. This provides as much variability as possible in both directions before the spring bottoms out when the system is hot. This design was necessary prior to effective computer modeling of piping systems, when the weights at hangers were approximated by chart methods or calculated by hand. Activating this option does not guarantee that spring hot loads are at the middle of the spring table, but CAESAR II makes every effort to move the hot load to this position. The CAESAR II design algorithm goes to a higher size spring if the design load is closer to the middle of the larger spring's range, but never switches spring types. This option, when it is effective, can only result in a one-size larger spring. CAESAR II attempts to move the hot load to the next higher spring when it is within 10% of the maximum travel range for the spring. If the new spring is not satisfactory, then CAESAR II uses the old one.