Pipe weight dist, thickness selection

[kbus12]

All,
I have a PM that wants to manufacture a type of mist extractor off a 3" blow-off. My concern is the weight distribution of an 8" pipe located vertically on top of a 3" blow-off. I've attempted to calculate mass but didn't find a reliable density of API 5L ERW X42 steel; does anyone have a density sheet for different grades (my first question). And if anyone could suggest some resources to determine -- pipeline weight distribution, thickness selection, etc.. -- I would greatly appreciate it.

Likely, I'll look into a 3" flange set-up prior to the steel plate and 8" pipe -- no reducer unless necessary. I've also suggested elbowing over and running 8" to the ground. But this got me thinking, and I would like some resources for future issues.

Thanks,
Kbus12

 

[bimr]

US Steel has the pipe information:

http://usstubular.com/connections/sl/

 

[canadapipe]

API 5L pipe mass would be as per section 9.11.2 calcs. For typical applications though most pipe vendors will be able to supply you with a data book for all pipes and WT giving the corresponding weight per foot.

Also I believe Bri-Chem have a app for calculating this where you can select the OD and WT and it will give you the weight per foot.

 

[LittleInch]

This is one place where a suitable drawing or sketch would be very useful as I can't work out what you mean by "the weight distribution of an 8" pipe ". I've not seen densit change by grade and I have always used 7800 kg/m3. Any minor change in this won't affect the weight of an 8" piece of pipe very much.

thickness selection is determined by the design code, internal stress, other stresses and practicality.



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

 

[kbus12]

Thank you very much for your responses.

Attached is a mist extractor I found on Mueller's site. As you can make out, the smaller diameter pipe is welded directly to a steel plate (at least in my situation) with a hole to allow for flow. The larger diameter pipe is then welded onto the plate with closure and necessary appurtenances.

 

[LittleInch]

And your problem is?

So long as the incoming pipe is right in the middle of the plate and your nozzle is vertical then all you have is vertical weight and a bit of wind force maybe.

If not then I can see where you might be concerned, but the variation in wall thickness will be much more than the variation in steel density.


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

 

[kbus12]

When operations blows down, I imagine there will be some potential movement (minimal). But at a certain mass, the top-heavy design could allow for bending and possible failure. The situation reminded me of a static free body diagram equation. I would like to mathematically prove that the design will hold if say-- the smaller diameter pipe would sway left or right a degree or two.

 

[kbus12]

From there, I can suggest length, size, thickness, weight, etc..

 

[LittleInch]

If you're that worried about your flange then you need to brace this off the vessel or something else or detach it and pipe it somewhere else. Flanges will stand a lot of abuse and 1 or 2 degrees shouldn't be an issue. it does look a bit of a monster thing to put on a flange direct off a vessel, but I've seen worse.

you now have density and weights so if you want to do this you can.

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

 

[dhengr]

Kbus12:
It seems to me that you have asked your question in kind of a strange way, and left anyone who might try to help you wanting for the info. needed for a meaningful discussion. Standing vertically on top of a vessel, as is its orientation in the picture you show, you probably don’t have much of a problem. Unless, of course, its blow down causes serious vibration of the entire unit. If on the other hand, this unit is hanging off the side of a vessel, from the small flange at the bottom of your picture; that is your picture is rotated 90̊ clockwise or counter clockwise, then you likely have a potentially bigger problem. Because, now the mass is hanging out in mid air some distance from the flange and causing bending and increasing the damage that any vibration might do, from wind or blow down, etc. And, in that bending orientation you probably have some significant bending, stresses, stress raisers and the like.