Pipe fittings question! 1

[Flow-rider]

Hello everybody...
I'm currently on my probation work in oil/gas industry firm...

I'm studying one, lets say brochure, and it contains fitting names which i'm unfamiliar with. I probably saw them, and know some of them on my Croatian language but on English, i have hard time to understand how those fittings look like.

Can please somebody post google image / web page links so I can see directly what those fittings look like.

This are the names:
bends with <3d straight pipe between
heavy wall bends
tees with <3d straight pipe between
unbarred full bore tees

Thanks everybody on help!

 

[LittleInch]

Is this piping or pipelines?

Piping they tend to call these elbows, usually "Long Radius" which means 1.5D.
Pipelines have "bends" which are usually min 3D and often 5D.

bends with <3d straight pipe between - no known word, but there are "U" bends called Long Radius Returns
heavy wall bends - No known word to differentiate thin from heavy wall
tees with <3d straight pipe between - Tess are tees. These are just welded end to end or "fitting to fitting" as it's sometimes called. You usually want at least 1D of straight pipe or weld them together. But this is custom - you won't find that in any code.
unbarred full bore tees - Equal Tee

Look up ASME B 16.9 for some of these and their standard dimensions, but other codes are available.


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

 

[GBTorpenhow]

This sounds like a list of things that can make a pipeline difficult or impossible to pig. Rather than describing individual fittings these descriptions are of combinations of fittings or configurations that should be avoided in a piggable pipeline.

"unbarred full bore tee" is just a regular tee - a "barred tee" has bars in the branch so a pig wont nose into the branch and get stuck:

"tees with <3d straight pipe between" Putting two tees close together can cause a pig to get stuck:

https://www.apachepipe.com/assets/why-pigs-get-stuck.pdf

 

[Flow-rider]

First and foremost,
I'm sorry for this delay in replying...

@LittleInch:

Is this piping or pipelines?

Piping they tend to call these elbows, usually "Long Radius" which means 1.5D.
Pipelines have "bends" which are usually min 3D and often 5D.

I'm taking about long distance pipelines, or to be more specific, all this is referred to IN LINE INSPECTION, that's where I'm finding these expressions.

bends with <3d straight pipe between - no known word, but there are "U" bends called Long Radius Returns
heavy wall bends - No known word to differentiate thin from heavy wall
tees with <3d straight pipe between - Tess are tees. These are just welded end to end or "fitting to fitting" as it's sometimes called. You usually want at least 1D of straight pipe or weld them together. But this is custom - you won't find that in any code.
unbarred full bore tees - Equal Tee

Tnx for the clarifications...I will go with your descriptions...
Even tough some of them are still logically hard to describe to myself...like heavy wall bends? Considering that's mentioned in IN LINE INSPECTION questionnaire, that means it can make a difference (special version of heavy wall?). In my head then that's a special bend with thicker wall = inside diameter is smaller that nominal diameter of pipeline before/after that specific bend = obstruction of passage for pigging tool/Smart pig.

unbarred full bore tees; tees with <3d straight pipe between - ok, I understand know what those are.

Look up ASME B 16.9 for some of these and their standard dimensions, but other codes are available.

I will, thanks.

 

[Flow-rider]

https://www.apachepipe.com/assets/why-pigs-get-stuck.pdf

Thank You very much for this link.
This is very helpful...

Visually very helpful article.

 

[LittleInch]

Ah,

You should have said earlier what your issue was about.

Intelligent pigs, as opposed to "normal" pigs are usually quite long, sometimes up to 4 to 5m in length and composed of a number of articulated sections.

The contractors know from experience that there are some configurations of pipe which they just don't like and have a high possibility of either getting stuck or causing damage to the expensive pig.

So your list again.
bends with <3d straight pipe between - Pipeline bends usually come with straight lengths between the end of the bend of between 0.5 to 1m. However in some cases bends can be cut back or larger diameter pipe means the bend is less than 3D apart. This means the intelligent pig is trying to go two directions at the same time. At worst this is like a Z where two 90 degree bends occur within the length of the pig.

heavy wall bends - Pipelines, especially gas pipelines, often have what is called "heavy wall" where the Design factor is 0.6 to 0.3 compared to the normal pipe which is 0.72. This is used at road and rail crossings or where there are occupied buildings close to the pipeline. This leads to a smaller ID.

tees with <3d straight pipe between - GBTs drawing is excellent to show why this is an issue

unbarred full bore tees - again GBTs picture is good. Pigs have an unnerving ability to do things you wouldn't have thought possible. It is quite easy for a full bore equal tee to get a pig going into the branch pipe and getting wedged there. I once saw a pig manage to reverse itself doing this ( a small bi di pig). I doubt there are many operators who would actually allow the pig run to happen if they thought there was a full bore equal tee without bars.


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