Lifting Lug in Major and Minor Barrel in PVELITE 1

[SmallInfo]

Hi Experts,
I am designing a pig receiver with two barrels: a 6-meter major barrel and a 7-meter minor barrel. The barrels are joined by an eccentric reducer. I need to add lifting lugs to the major and minor barrels at different elevations, but PV Elite is placing the lugs at the same elevation as shown in the image. Does anyone have experience adding lifting lugs to different elevations in PVELITE?
Thanks in Advance

 

[0707]

I am not an expert on this matter, but lifting lugs at diferent levels put some dificulties on the lifting of the equipment.

 

[LittleInch]

Pig traps are not Pressure Vessels.

So why are you using a PV program?

Also the size is huge. You rarely need major and minor barrels that long.

Remember - More details = better answers
Also: If you get a response it's polite to respond to it.

 

[DriveMeNuts]

littleInch sticking his nose in where it doesn't belong.
Pig Traps can be pressurised, and therefore PV software can be useful in the design.
I'm not very familiar with PVElite, but I would expect that you could model each lug separately, like they were support brackets.

 

[LittleInch]

Really?

of course pig traps are pressurised, just like pipelines and pipe, but you don't analyse those designs as though it was a Pressure Vessel do you?

Pig traps are deliberately included in pipeline design codes to avoid mismatches between the design of the two directly connected systems.

If you can avoid the problem in the first place then it solves all the concurrent ones.

I can only guess PV Elite doesn't see many pressure vessels with different diameters welded together.

Remember - More details = better answers
Also: If you get a response it's polite to respond to it.

 

[r6155]

1) Do the calculations without the computer.
2) Use the same lifting lug for both diameters and lift with a spreader bar.
3) But why use lifting lugs? For horizontal pressure components use slings around the shell,and lift with a spreader bar.

Regards

 

[MJCronin]

I agree with r6155 .... Find someone competent with pressure vessel, piping and lifting lug experience.

Manual calculations can always be performed ... by competent people

The problem, of course, is inexperienced twenty year old "STEM engineers" who only know how to follow prompts on computer screens. Designing pressure vessels is only another kind of video game to these people ...

I also agree that lifting lugs are optional and not necessarily required, in this particular case... As is typical with most third-world postings, we cannot see the entire pigging piping assembly, so ... who knows !!! ????

The entire lifting/rigging assembly and lift beam should be designed at this time .... IMHO

MJCronin
Sr. Process Engineer

 

[SnTMan]

SmallInfo, I have forgotten most of the little I knew of PVElite, but:

I seem to recall it being finicky about which from-to nodes were selected when various components were inserted. Is it possible the software thinks both lugs belong to the large cylinder? Can you maybe insert one lug on each cylinder?

Note I take no position on issues raised by previous posts

Regards,

Mike

The problem with sloppy work is that the supply FAR EXCEEDS the demand

 

[akpipelineengr]

I'm with LittleInch on this. Pig barrels are part of the pipeline.

It's worth nothing that both B31.4 and B31.8 have limitations on what can be welded to the pipeline. B31.4 in particular basically prohibits lifting lugs and other attachments being welded directly to the pipe. In this case, full encirclement sleeves would be required to attach those lugs to the barrel.

 

[r6155]

I have never seen pig traps with lifting lugs.

Regards

 

[SmallInfo]

Thank you so much guys for you valuable feedback and time, I calculated everything manually and double checking my calculations in pvelite. Governing code is B31.8

 

[LittleInch]

From B 31.8

pig trap: an ancillary item of pipeline equipment, such as a
launcher or receiver, with associated pipework and
valves, for introducing a pig into a pipeline or removing
a pig from a pipeline.

No mention of it being a PV....

Remember - More details = better answers
Also: If you get a response it's polite to respond to it.

 

[Trestala]

SmallInfo, as suggested by others above, do not apply a lifting lug to this piping.
This is normally lifted by a sling wrapped around the shell/pipe.

You have a lifting lug located at the top and the radial loading on that may deform the shell unless you have evaluated it will not, especially for a 6m and 7m dia. shell.
That calculation by the software is only for the strength of the lug and localized stress around it.
If you are forced to use a lifting lug, you better apply 2-lugs located at 45deg~90deg and 315deg~270deg opposite of each other.

 

[SnTMan]

An aside: I often see advice, "don't use lift lugs, instead lift with slings".

OK as far as it goes. But vessels are often insulated before being installed, say in structure. Slings are out, lugs or trunnions are the alternative.

The problem with sloppy work is that the supply FAR EXCEEDS the demand

 

[DriveMeNuts]

LittleInch, these items of pressurised equipment 'can be designed' as Pressure Vessels.
A workshop I worked for fabricated pig launchers. They didn't have expertise or software for piping codes, so they were designed to pressure vessel codes instead, where the thickness of the pipe complied with piping code.
They were lifted with a sling.

 

[LittleInch]

They can be of course, but shouldn't be.

That excuse is rubbish. IMHO.

Remember - More details = better answers
Also: If you get a response it's polite to respond to it.

 

[Groombride]

Hello @smallinfo please can you share how you designed a pig trap using PV Elite, Thank you.