Pipeline alignment sheets 2

[zsa]

Hi,

Recently started dabbling in pipeline design at work, and came across a term 'Reduced level at point of intersection' on the pipeline alignment sheets showing the plan and profile for the pipeline. Would anyone be kind enough to explain what this means exactly? The pdf is attached in the link below

Also, what do the 'to be cut' and 'to be backfilled' labels indicate?

Secondly, please recommend some good resources to get brushed up with all pipeline design basics and fundamentals I would need to know as a pipeline engineer? Looking to expand my skill set and so far, I have got my hands on Pipe stress engineering by LC Peng- wondering if this is a good place to start.

I would truly appreciate your help in this matter

Cheers

 

[LittleInch]

Please please don't "dabble" in this. It will go horribly wrong.

These are simple civil engineering terms indicating that for some reason the pipeline designer doesn't want to follow the contours, but wants to have a small gradient, so I can only assume this is a sewer or some other form of gravity draining pipe.

Hence all the material shown as "cut" is removed from the current hillside, with a small amount going to "fill" the holes in the ground from 0 to 70m.

Point of intersection is a new one on me, but appears to be finished ground level after the 40" pipe has been installed and the earth backfilled over the top of it. What it means is you're cutting a large hole in the hill to place your pipeline.

Possibly a bit like this if you think of your 40" pipeline under the railway.

I'm a little reluctant to recommend any such tomes to someone who can't grasp such simple fundamentals as this, sorry.

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

 

[DGrayPPD]

zsa, before work begins on the pipeline, civil construction must be carried out as i'm sure you are aware. They must grade out the earthwork and due to natural changes in elevations from hills, valleys, etc., certain areas of the earth must be "cut" and "filled" to level out the construction surface. This is necessary for different reasons such as trenching and laying the pipeline. As you can see in your attachment, if the pipeline is run at the proposed elevation of 15m, it will eventually become exposed once it reaches a certain point. Also, the area to be cut is necessary for trenching. Otherwise, think about how deep of a trench you would need if you did not cut and grade out the hilly areas and how much of a construction/safety nightmare and how impractical this would be.

I've also attached a link for the "reduced level" part of your question, as my knowledge isn't quite where I'd like it to be on that subject. I'm sure others with more knowledge on the subject will be along soon.

https://en.wikipedia.org/wiki/Reduced_level

And lastly, I've asked a similar question in the past when trying to increase my knowledge on pipeline design. You can view some of the helpful responses I received in the link below.

http://www.eng-tips.com/viewthread.cfm?qid=426117

Volume 1 & 2 of IPLOCA "Onshore Pipelines - The Road to Success" were recommended to me and I found them very helpful.

 

[Gator]

"I'm a little reluctant to recommend any such tomes to someone who can't grasp such simple fundamentals as this, sorry."

This is related:

There was a recent post at LinkedIn (from a 'Senior Piping Designer / Piping Project Lead' with 5800 followers) that asked about standard height for control station bypasses.

I could not believe that such a question was being asked by someone with a job title like that.

Is piping design now just the ability to operate specific software? Are people now routinely promoted to positions where they do not even understand the basics of their discipline?

 

[DGrayPPD]

Gator,

"Is piping design now just the ability to operate specific software? Are people now routinely promoted to positions where they do not even understand the basics of their discipline?"

Short answer... for the most part, yes.

The experienced mentors still out there are scarce. And the new up-and-comers "don't know what they don't know" as the saying goes. But when you don't have anyone to ask questions to, what do you do? I guess one option is to ask questions on a forum like me. Or seek out experienced advisors as best you can. The more I learn, the more I realize the lack of knowledge and understanding that plagues this profession today. But I appreciate the advice I'm given and I will continue to try and return the favor whenever I can.

 

[zsa]

Thanks for the reply guys. To shed some light on the situation, I am a fresh design engineer and am being made to 'rotate' through different departments. I am due to start pipeline design with one of the senior engineers but I wanted to get a jump on that and start from now- this is why I posted this question

I wholeheartedly agree with DGrayPPD; if newbies/newcomers like me dont ask on forums like this where there are plenty of experienced and knowledgable engineers to help them out, where else do we go? Unfortunately not every company has a lot of 'senior' people with the requisite technical expertise as Gator pointed out in his reply.

Note that by 'dabble' I dont mean to imply that I will only have a cursory look at some standards and start designing pipelines; I just want to get a basic understanding and develop a 'gut-feel' for the subject so it comes more naturally to me when I do eventually get down to designing it on softwares and such.

 

[Gator]

"the lack of knowledge and understanding that plagues this profession today"

and

"not every company has a lot of 'senior' people with the requisite technical expertise"

Those experienced people absolutely are out there (I know dozens of them myself, they are unemployed - some long-term) but there appears to be little incentive to hire them. Of course there are a bunch of possible reasons for this but I won't verge too far off-topic here.

 

[fel3]

I'm a civil engineer, took two semesters of surveying in college, have done a bit of field surveying over the years, and work with surveyors quite often, and I have never heard the term "reduced level." But here is California, everything is "groovy" (I'm dating myself) and "dude", so it's not surprising.

I note a few other terminology differences. For example, I would not use "route" for the horizontal and vertical positioning of the pipe. Instead, I would use "alignment". To me, "route" is general and not quantified (e.g. "we are routing the pipe down Main Street") and "alignment" is specific and quantified (e.g. "the pipe alignment is five feet south of the centerline of Main Street").

Here, "chainage" would be "station" or "stationing".

Here, "point of intersection" usually refers to the intersection of the two tangents of a circular arc. On your drawing, it appears to be the intersection of the chainage with the existing ground profile (no parentheses) and with the finished grade profile (in parentheses).


A few other comments:

I would have called out the existing ground profile and finished grade profile specifically, rather than imply their existence with "to be backfilled" and "to be cut".

The "pipeline route" in profile needs to indicate if this is the top of pipe, soffit of pipe, invert of pipe, bottom of pipe, or (heaven forbid) centerline of pipe (I prefer top or invert, and only use centerline for plant piping. As just a line with an ambiguous callout, it's meaningless. I suppose "trench bed profile" (which implies bottom of pipe) along the bottom of the profile salvages this situation, but that's not how I would have done it.

I would not mix systems of units by calling out the pipe diameter in inches. Everything else is SI, so the pipe diameter should be also. I was once mandated by a client [U.S. Navy] to mix units because the survey I received from them was SI, but the project architect convinced the Navy's PM that the building should designed using US Customary. My project engineer and I made it work, but never again.

In the "Pipeline Data" table, i would spell out "Hydraulic" instead of using an abbreviation. It's not like there isn't room. Even though it would be nonsensical here, "HYD" is also used as the abbreviation for hydrant and hydrology, and possibly even for Dr. Jekyll's alter-ego.

I notice that horizontal control is missing from this drawing (chainage isn't sufficient for actually locating the alignment). I hope horizontal control is shown somewhere in this plan set (maybe it's in a table somewhere). By horizontal control, I mean coordinates for the alignment along with curve data (radius, angle, length, etc.). Coordinates should be provided for each point where the alignment changes (like elbows and beginnings and endings of curves), centers of curves, survey control monuments, etc. Some people use bearing and distances for pipeline alignments, but coordinates are more reliable. If you bust one coordinate, you have busted at most two legs of an alignment. If you bust a bearing and/or distance, you have busted the entire alignment past the busted leg. Even in the days of Civil 3D, it is possible to bust these.

I have to quit now. I ran out of parentheses.

==========
"Is it the only lesson of history that mankind is unteachable?"
--Winston S. Churchill

 

[LittleInch]

zsa, dgray,

I fully appreciate learning and I actually do lectures on pipeline engineering to both students and young professionals to try and share some knowledge built up over many years.

However I only knew where you were coming from from your second post. Go and look at the first one and think how was anyone else supposed to know your background. On this forum we get many and varied posts, some form people who are convinced that asking a few questions on an online anonymous forum means they can go out and build things which have the potential to harm a lot of people or the environment. So I may have come down a bit hard, but sometimes you need to make a stand...

If you follow the inks in the post Dgrey supplied it will get you quite a long way up the learning curve.

Having a closer look at your alignment sheet this is a 40" pretty thin GRP pipe. GRP is a great material for many things, but it's not a great pipeline material. Personally I think it's more trouble than it's worth. You have a lot more issues to deal with than simply moving a large hill out of the way....


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

 

[zsa]

fel3,

Truly appreciate the detailed reply. Appreciate the input; I shall look into the 'horizontal controls' and bring it to my supervisor's notice

LI:
I realize that it would have better served my purpose to give some background in the original post. I appreciate where you're coming from, and you coming down hard on the initial post (which , in hindsight, didn't really help my case) is justifiable; heck, its commendable. I am a newcomer to the forums here but I already feel like I am getting a much better understanding by reading comments by you ( and other users e.g BI) and other users on this thread.

You raise an interesting point about GRP- Again, I shall look into using GRP in pipelines vs other materials.

DGray: Thanks again for the link

 

[DGrayPPD]

LI,

Do you offer webinars of your lectures?