ASME B31.8 and ASCE 7-16 Wind Load 1

[structure_engineer]

Since ASCE 7-10, the wind load is strength level for 1.0 Wind. For pipe stress calculations, do you use allowable stress design or strength level wind loads?

In COMPRESS Pressure Vessel Design Calculations, which is a Mechanical discipline related function, there is this section:

I have attached the load combinations of a vendor on a slug catcher stress calculation. It seems like they mix the strength level load factor with the nominal weight of pipe which is allowable stress design. I have no exposure to ASME B31.8. Thus, I am asking for any Piping Engineer who can help me to sort this out. I have downloaded ASME B31.8 and could not find any load combinations in the document. As far as I know, allowable stress design load combination could not be mixed with ultimate strength design load combinations. I have a set of load combinations for Load and Resistance Factor Design for structural steel members and a set of load combinations for allowable load values for pile design. There is very distinct difference between these sets of load combinations. In the attached file, should Load Combination 46 be like:

46 (OPE) W+T3+P2+0.6WIND1?

All load cases with wind load, there should be a 0.6 load factor? Your input is much appreciated. Have a Happy New Year!

 

[saplanti]

Structure_engineer,

I agree with you. However, all the clients are not the same. Some of them are with lack of knowledge. Whatever comes from piping engineer, they pass on other parties without even looking at it.In my previous works I used to prepare a spreadsheet for the purpose, mostly with unfactored loads, for structural/civil engineer by showing the considered directions of the analysis on the spreadsheet in addition to the print of the analysis model which shows the nodes. Structure/civil engineer used to factor the loads in accordance with the applicable code rules for the design on their side.

Sometimes clients or their structural/civil engineers ask for foundation drawings with marked loads which becomes a bit time consuming for pipe stress engineer.

I guess the piping analysis that you have includes structure connected and you are after the foundation loads. So you are able to get foundation loads directly from the analysis.

We need to be patient with the client, sometimes by educating them or their project engineers how and what to provide to relevant parties.

 

[StressGuy]

A 17,000 page stress report from 128 load combinations? That's not engineering, that's a tragedy.

And for a wind load on a slug catcher? I wouldn't even run wind cases for something like that sitting on the ground.

Edward L. Klein
Pipe Stress Engineer
Houston, Texas

"All the world is a Spring"

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

 

[r6155]

I am curious, can you tell us the pipe diameter and thickness?
Regards