Hanger Design Load Cases

Following hanger design load cases are defined for a piping system with T1= +75C, T2= -86C and ambient temperature = 0C:

LC No. Load Cases Input Load Case Name
1 W+(P1) Restrained weight case
2 W+T1+P1 Operating case 1
3 W+T2+P1 Operating case 2
4 W+T1+T2+P1 Operating case 3
5 WNC+P1 Installed load case

Hanger Input: Node number
Hanger Design Control Data:
No. of Operating Load Case: 3
Calculate Actual Cold Loads: yes
Allow Short Range Springs: yes
Hanger Table: 5 – Lisega
Multiple Load Case Design Options: 13-Max Load & Travel

My questions are follows:

1. What should be included in restrained weight case? With P1 or without it?
2. Which operating case is deciding load case? Is the operating case 3 important for hanger design or it is not necessary to be considered?
3. I thought “size” and “spring rate” in hanger report are enough for hanger selection. How should I regard other parameters in the hanger report?
4. Horizontal Movement is given in hanger report. What is this mean?

I have no experience for hanger design and hanger selection. I hope somebody can help me.

Regards!

Hello ghx,

You will receive responses to your specific questions later in the day. However, to learn more about hanger design, download this document and read it:

http://www.anvilintl.com/db/datasheets/Pipe_Hanger_Design-05.pdf

Regards, John.

Servus,

First: usually W only is usually run for the weight the hanger has to carry.

Second: the hanger selected should "work" for both operating cases that is it should remain in the Minimum Maximum load range and its variabilty should not exceed ~25% or so. So both operating cases are equally important.

Third: Size and spring rate are important but the hangers must be preloaded at time of order. To do so the vendor needs to have either a cold load set, or hot load set and travel. See the hanger vendors ordering requirements in their catalog.

Fourth: Horizontal movement means operating displacement in X OR Z. Assuming the spring selected is a rod hanger the hanger rod must be long enough to prevent a swing ange from exceeding ~ 4 degrees.

These are all very basic questions... as I see it you need to do some self education quickly, read John Breens reference closely. My Deutsch is kleine I hope your Amerikanishen is better than my Deutsch!

Thank you for quick reply.
John C., my second question was if the third operating case is necessary? Danke.

I presume you mean....

4 W+T1+T2+P1 Operating case 3

I would say keine! It is a non operating case, in other words how could the system ever be cold and hot at the same time?

Vericht no?