Pipe Sleeper on a Sloping Line

I have no idea what is advisable of concrete pipe sleeper designs. As the abstract of the thesis link points out, "Current design methods for sleeper-supported pipes are not rational and are believed to be excessively conservative."

I will tell you what is a good business and fabrication practice. Follow the engineers design! If the design cannot be executed as designed for any reason, seek out the engineer for an alternative. Offering the engineer a possible alternative plan is nice but don't be surprised if your plan is not used. Do not alter from the design without approval.

Shaff,

You need to give us more & better information.

- What is the Schedule (wall thickness) of the pipe?

- What is the length of the flat part(s) of the line?

- What is the spacing between all supports under flat part of the line?

- What is the length of the sloping part of the line?

- What will the spacing be between the supports under the sloping part of the line?

The OP started this thread with just three sentences. The first and third sentences are direct and indirect questions respectively. Only the second sentence provides any clear information. For accuracy I will quote the second sentence.

"I have a 12" header rolling 9 degree vertically and a sleeper is shown in the drawing."

There is a drawing. A drawing is a written plan. This drawing may not be a complete plan but it is a plan none the less. The OP is asking a bunch of strangers if the plan that we cannot read is a good plan. We do not know if this particular drawing is a precise architect drawing with a presumed mechanical engineer license and credibility behind it or just a pencil sketch on a note pad. However, there is a drawing.

I don't see the OP proposing to change/not follow the drawing, but to more thoroughly understand the reasoning behind it.

It never hurts to ask questions, nor does it hurt to gather information before going back to the designer. Whom you ask may be a problem, however: possibly the OP doesn't want to risk asking a stupid question, or risk looking stupid by asking it. It happens. Much safer to ask the question elsewhere and possibly even get the question answered to his/her satisfaction, forestalling any need to bring it up at all. We've all worked for arseholes, yes?

We don't know the OP's situation; possibly the OP is more concerned that the designer might do precisely what we are doing here: reading more into the OP's question than is actually there.

"Presumably the original drawer of the drawing should be asked about the design, not a bunch of strangers."

In an ideal world, yes, but neither is the OP required to accept advice proffered by a bunch of strangers or even deem it worthwhile, nor is asking questions of both parties mutually exclusive.

Asking questions of others who potentially may offer good advice (this is an engineering forum and not Facebook. I hope) is never a bad idea and may in fact result in one's gaining insights, insights that one might not have otherwise had.

If the advice proffered is good, all the better. If it's bad, one always has the option of rejecting it. Moreover, asking a bunch of strangers does not preclude asking others as well; perhaps the OP has already asked the designer and wasn't satisfied with the answer. We don't know. We simply do not know, but to dissuade the OP or anyone else from asking questions would be a travesty. We've all worked for people who did things "because we've always done it that way." It's an answer, yes, but it doesn't answer the question. What would be our advice to us, then? "Just pay attention to their credentials and/or title, not what they actually know"? I've worked with plenty of people who looked great on paper but didn't know shit. They got to that position by stealing others' ideas, kissing arse or just plain doing what they did best: looking good on paper. If we've been in the workforce long enough, we all know at least one.

For example, years ago our VP of Engineering (who was ultimately fired) was an MIT CompSci PhD who questioned the utility of using interrupts in a real-time system and told us in a meeting to use polling instead. I thought (but didn't say) 'Polling? In a real-time system? You've got to be f**king kidding!' What I did say was this:

"Okay, Neil, let's say you've 300 phones on your very large executive desk, but the ringers have all been disconnected. So, in order for you to tell if someone is trying to call you, you have to go round and hold each handpiece to your ear and listen briefly for someone at the other end. If you're lucky, they won't have hung up before you picked-up that handset. It could have been a life-changing call, but how would you know? You missed it. And so around you go, round and round, picking up each handset, one at a time, to see if someone is calling. Now, would you consider that an efficient use of your time? I didn't think so."

If the OP has any sense at all, he/she will continue asking questions - even of a 'bunch of strangers.' Asking the question is not the issue so much as it is what you do with the answers.

Need much more information. How long is the sloped portion? is it rolled or branched off a perpendicular straight? Is the rest of the piping on sleepers?

I see nothing wrong with supporting a sloped portion with sleepers, of itself, but the Devil is in the details.

While I was sleeping peacefully (Middle East), my stupid/genuine/reasonable (strike out which doesn't apply to your perception) question has made a big debate here…

The Project: To make existing 16" 20Kms PIPELINE piggable byinstalling a 16" Mobile Pig Receiver by cutting the line inside a relatively crowded (with piping I mean) HIPPS station.

My Role: I am a Piping Engineer from EPC contractor. "E" of EPC is subcontracted to a reputed Engineering Consultant (European MNC). I basically work in Engineering Department and have been assigned to manage consultant (piping discipline) and act as a focal point between consultant and End User. I am also responsible to look after the technical issues we may encounter during execution.

Background to my Question: 16" Mobile Pig Receiver is to be installed in the free area near the access road as planned. Line will be cut nearest to the road and will be routed near the road using two 5D bends. With a 16X12 bar tee, 12" by pass line will go and join with the line again at the nearest point. Piping GAD and all relevant documents have attained Approved for Construction (AFC) status.

However, when the civil team finished marking for foundation excavation, Client Operation team was astonished to see the 12" by-pass line running across the access road. The access road is 8mX40m asphalt road which was partially occupied by this new line (road would become 5 meter short and 2 meter thin. That is 6X35 meters). PTW (permit to work) was cancelled, project manager was summoned by the top guns from client operation and everybody turned their face toward the consultant. The consultant just sarcastically replied "This is as per FEED and client is already aware of this" and to their support the drawings are AFC by the very client who is objecting the routing". The client is after all "CLIENT" so they overruled their AFC judgment and asked the contractor to study the alternate routing to keep the road open. They have denied any variation request stating that this is a mistake from consultant that they didn't take care of accessibility.

When this was asked to consultant, they have asked for a heavy variation which we have to pay them for their mistake. Consultant argues that they have the right to claim since drawings are once AFC. Client argues that its contractor's mistake.

Ultimately, the person to do this whole thing again is ME…!!! Go to site, talk to those "already angry" operations, convince my site supervisor to come along to take some measurement etc etc etc…. Of course it covers stress analysis and support study. I know how to do it also.

So during this course, while I was studying the 12" routing I saw a pipe sleeper on a 9 degree sloping line which "I felt" is not proper. I asked many here already did not get convinced. I can't ask the consultant, to utter "HELLO" over the phone, he asks for money… So I just posted the question in forum hoping for some outright "YES" you can or "Are you crazy, NO you can't" which I could have taken as "They do it at times" or "Hmm..It never happens then". I, or many of us are aware this is not the ultimate source for getting technical advises, but I do not have the privilege of working under some 20-30 year experienced engineers here.

I am trying to find why at all we need to give this type of sloping sleeper. Cant we just relocate the pipe support in the straight portion (without affecting the integrity)?