B31.1, SUPPORTS FOR SUSTAINED LOAD CONDITION??

[carletes]

Hello all!!

I have a question, perhaps too easy for some of you, but it's making me go crazy.

I am calculating a piping system according to Ansi B31.1. As you know, several comprobations must be perfomed: pressure, sustained load and expansion condition. My question refers to sustained load calculations (including piping weight, pressure, insulation and valves weight etc)
In this case, if there are any supports that I know are going to lift during operation due to expansion, must they be considerated in the sustained load case calculations? Becasuse I think ANSI doesn't say anything regarding it, but if I considerate those supporting points or not, my pipe fails or not.
I hope having explained myself "decently" (my English is not that good)

Any help will be really welcomed.

Thanks.

 

[amebo]

Hola!
Tu idioma es el español?

 

[carletes]

Sí, aunque creo que en estos foros es mejor escribir en inglés.
Entiendes mi pregunta?

 

[StressGuy]

If your support lifts in operation, you can't take credit for it in the consideration of sustained stresses. When you find a support that is lifting, you should remove it from your model, rerun and then check sustained stresses to see if they are within the allowable. Edward L. Klein
Pipe Stress Engineer
Houston, Texas

All opinions expressed here are my own and not my company's.

 

[LSThill]

Hi carletes (Chemical)and StressGuy (Mechanical)

StressGuy, Mr. carletes may not be using a Piping Stress Program.

Note: Mr. carletes, may not even have a PIPING STRESS SPECIFICATION, whick will address the below:

104.8 Analysis of Piping Components

To validate a desing under the relis in theis paragraph, the complete pipng system must be analyzed between anchors for the effectis of thermal expansion, weitht, other sustained load, and other occasional lands, Each completent in the system must meet the limits in this pargraph.

RE: ASME B31.1-2001 PG. 104.8.1 Stress due to Sustained Load. The effects of pressure, weight, and other sustained mechanical loads shall meet the requirements of Eq. (11).

104.8.2 Stress due to Occasional Loads. The effects of pressure, weight, other sustained load, and occasional loads including eqrthquake must meet the requirement of Eq. (12).

104.8.3 Thermal Expansion Stress Range. The effects of thermal expansion shall meet the requirement of Eq.(13).

Leonard@thill.biz

http://www.thill.biz